Dan Carpenter [Mon, 25 Apr 2022 11:56:48 +0000 (14:56 +0300)]
dm integrity: fix error code in dm_integrity_ctr()
commit
d3f2a14b8906df913cb04a706367b012db94a6e8 upstream.
The "r" variable shadows an earlier "r" that has function scope. It
means that we accidentally return success instead of an error code.
Smatch has a warning for this:
drivers/md/dm-integrity.c:4503 dm_integrity_ctr()
warn: missing error code 'r'
Fixes:
7eada909bfd7 ("dm: add integrity target")
Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jonathan Bakker [Sun, 27 Mar 2022 18:08:51 +0000 (11:08 -0700)]
ARM: dts: s5pv210: Correct interrupt name for bluetooth in Aries
commit
3f5e3d3a8b895c8a11da8b0063ba2022dd9e2045 upstream.
Correct the name of the bluetooth interrupt from host-wake to
host-wakeup.
Fixes:
1c65b6184441b ("ARM: dts: s5pv210: Correct BCM4329 bluetooth node")
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Link: https://lore.kernel.org/r/CY4PR04MB0567495CFCBDC8D408D44199CB1C9@CY4PR04MB0567.namprd04.prod.outlook.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Steven Rostedt [Tue, 5 Apr 2022 14:02:00 +0000 (10:02 -0400)]
Bluetooth: hci_qca: Use del_timer_sync() before freeing
commit
72ef98445aca568a81c2da050532500a8345ad3a upstream.
While looking at a crash report on a timer list being corrupted, which
usually happens when a timer is freed while still active. This is
commonly triggered by code calling del_timer() instead of
del_timer_sync() just before freeing.
One possible culprit is the hci_qca driver, which does exactly that.
Eric mentioned that wake_retrans_timer could be rearmed via the work
queue, so also move the destruction of the work queue before
del_timer_sync().
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: stable@vger.kernel.org
Fixes:
0ff252c1976da ("Bluetooth: hciuart: Add support QCA chipset for UART")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Craig McLure [Tue, 24 May 2022 06:21:15 +0000 (08:21 +0200)]
ALSA: usb-audio: Configure sync endpoints before data
commit
0e85a22d01dfe9ad9a9d9e87cd4a88acce1aad65 upstream.
Devices such as the TC-Helicon GoXLR require the sync endpoint to be
configured in advance of the data endpoint in order for sound output
to work.
This patch simply changes the ordering of EP configuration to resolve
this.
Fixes:
bf6313a0ff76 ("ALSA: usb-audio: Refactor endpoint management")
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215079
Signed-off-by: Craig McLure <craig@mclure.net>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220524062115.25968-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Takashi Iwai [Sat, 21 May 2022 06:53:25 +0000 (08:53 +0200)]
ALSA: usb-audio: Add missing ep_idx in fixed EP quirks
commit
7b0efea4baf02f5e2f89e5f9b75ef891571b45f1 upstream.
The quirk entry for Focusrite Saffire 6 had no proper ep_idx for the
capture endpoint, and this confused the driver, resulting in the
broken sound. This patch adds the missing ep_idx in the entry.
While we are at it, a couple of other entries (for Digidesign MBox and
MOTU MicroBook II) seem to have the same problem, and those are
covered as well.
Fixes:
bf6313a0ff76 ("ALSA: usb-audio: Refactor endpoint management")
Reported-by: André Kapelrud <a.kapelrud@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220521065325.426-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Takashi Iwai [Sat, 21 May 2022 06:46:27 +0000 (08:46 +0200)]
ALSA: usb-audio: Workaround for clock setup on TEAC devices
commit
5ce0b06ae5e69e23142e73c5c3c0260e9f2ccb4b upstream.
Maris reported that TEAC UD-501 (0644:8043) doesn't work with the
typical "clock source 41 is not valid, cannot use" errors on the
recent kernels. The currently known workaround so far is to restore
(partially) what we've done unconditionally at the clock setup;
namely, re-setup the USB interface immediately after the clock is
changed. This patch re-introduces the behavior conditionally for TEAC
devices.
Further notes:
- The USB interface shall be set later in
snd_usb_endpoint_configure(), but this seems to be too late.
- Even calling usb_set_interface() right after
sne_usb_init_sample_rate() doesn't help; so this must be related
with the clock validation, too.
- The device may still spew the "clock source 41 is not valid" error
at the first clock setup. This seems happening at the very first
try of clock setup, but it disappears at later attempts.
The error is likely harmless because the driver retries the clock
setup (such an error is more or less expected on some devices).
Fixes:
bf6313a0ff76 ("ALSA: usb-audio: Refactor endpoint management")
Reported-and-tested-by: Maris Abele <maris7abele@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220521064627.29292-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sultan Alsawaf [Fri, 13 May 2022 22:11:26 +0000 (15:11 -0700)]
zsmalloc: fix races between asynchronous zspage free and page migration
commit
2505a981114dcb715f8977b8433f7540854851d8 upstream.
The asynchronous zspage free worker tries to lock a zspage's entire page
list without defending against page migration. Since pages which haven't
yet been locked can concurrently migrate off the zspage page list while
lock_zspage() churns away, lock_zspage() can suffer from a few different
lethal races.
It can lock a page which no longer belongs to the zspage and unsafely
dereference page_private(), it can unsafely dereference a torn pointer to
the next page (since there's a data race), and it can observe a spurious
NULL pointer to the next page and thus not lock all of the zspage's pages
(since a single page migration will reconstruct the entire page list, and
create_page_chain() unconditionally zeroes out each list pointer in the
process).
Fix the races by using migrate_read_lock() in lock_zspage() to synchronize
with page migration.
Link: https://lkml.kernel.org/r/20220509024703.243847-1-sultan@kerneltoast.com
Fixes:
77ff465799c602 ("zsmalloc: zs_page_migrate: skip unnecessary loops but not return -EBUSY if zspage is not inuse")
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Vitaly Chikunov [Thu, 21 Apr 2022 17:25:10 +0000 (20:25 +0300)]
crypto: ecrdsa - Fix incorrect use of vli_cmp
commit
7cc7ab73f83ee6d50dc9536bc3355495d8600fad upstream.
Correctly compare values that shall be greater-or-equal and not just
greater.
Fixes:
0d7a78643f69 ("crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm")
Cc: <stable@vger.kernel.org>
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fabio Estevam [Wed, 20 Apr 2022 12:06:01 +0000 (09:06 -0300)]
crypto: caam - fix i.MX6SX entropy delay value
commit
4ee4cdad368a26de3967f2975806a9ee2fa245df upstream.
Since commit
358ba762d9f1 ("crypto: caam - enable prediction resistance
in HRWNG") the following CAAM errors can be seen on i.MX6SX:
caam_jr 2101000.jr:
20003c5b: CCB: desc idx 60: RNG: Hardware error
hwrng: no data available
This error is due to an incorrect entropy delay for i.MX6SX.
Fix it by increasing the minimum entropy delay for i.MX6SX
as done in U-Boot:
https://patchwork.ozlabs.org/project/uboot/patch/
20220415111049.2565744-1-gaurav.jain@nxp.com/
As explained in the U-Boot patch:
"RNG self tests are run to determine the correct entropy delay.
Such tests are executed with different voltages and temperatures to identify
the worst case value for the entropy delay. For i.MX6SX, it was determined
that after adding a margin value of 1000 the minimum entropy delay should be
at least 12000."
Cc: <stable@vger.kernel.org>
Fixes:
358ba762d9f1 ("crypto: caam - enable prediction resistance in HRWNG")
Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Reviewed-by: Vabhav Sharma <vabhav.sharma@nxp.com>
Reviewed-by: Gaurav Jain <gaurav.jain@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ashish Kalra [Mon, 16 May 2022 15:43:10 +0000 (15:43 +0000)]
KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak
commit
d22d2474e3953996f03528b84b7f52cc26a39403 upstream.
For some sev ioctl interfaces, the length parameter that is passed maybe
less than or equal to SEV_FW_BLOB_MAX_SIZE, but larger than the data
that PSP firmware returns. In this case, kmalloc will allocate memory
that is the size of the input rather than the size of the data.
Since PSP firmware doesn't fully overwrite the allocated buffer, these
sev ioctl interface may return uninitialized kernel slab memory.
Reported-by: Andy Nguyen <theflow@google.com>
Suggested-by: David Rientjes <rientjes@google.com>
Suggested-by: Peter Gonda <pgonda@google.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Fixes:
eaf78265a4ab3 ("KVM: SVM: Move SEV code to separate file")
Fixes:
2c07ded06427d ("KVM: SVM: add support for SEV attestation command")
Fixes:
4cfdd47d6d95a ("KVM: SVM: Add KVM_SEV SEND_START command")
Fixes:
d3d1af85e2c75 ("KVM: SVM: Add KVM_SEND_UPDATE_DATA command")
Fixes:
eba04b20e4861 ("KVM: x86: Account a variety of miscellaneous allocations")
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Reviewed-by: Peter Gonda <pgonda@google.com>
Message-Id: <
20220516154310.3685678-1-Ashish.Kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sean Christopherson [Thu, 7 Apr 2022 00:23:13 +0000 (00:23 +0000)]
KVM: x86: Drop WARNs that assert a triple fault never "escapes" from L2
commit
45846661d10422ce9e22da21f8277540b29eca22 upstream.
Remove WARNs that sanity check that KVM never lets a triple fault for L2
escape and incorrectly end up in L1. In normal operation, the sanity
check is perfectly valid, but it incorrectly assumes that it's impossible
for userspace to induce KVM_REQ_TRIPLE_FAULT without bouncing through
KVM_RUN (which guarantees kvm_check_nested_state() will see and handle
the triple fault).
The WARN can currently be triggered if userspace injects a machine check
while L2 is active and CR4.MCE=0. And a future fix to allow save/restore
of KVM_REQ_TRIPLE_FAULT, e.g. so that a synthesized triple fault isn't
lost on migration, will make it trivially easy for userspace to trigger
the WARN.
Clearing KVM_REQ_TRIPLE_FAULT when forcibly leaving guest mode is
tempting, but wrong, especially if/when the request is saved/restored,
e.g. if userspace restores events (including a triple fault) and then
restores nested state (which may forcibly leave guest mode). Ignoring
the fact that KVM doesn't currently provide the necessary APIs, it's
userspace's responsibility to manage pending events during save/restore.
------------[ cut here ]------------
WARNING: CPU: 7 PID: 1399 at arch/x86/kvm/vmx/nested.c:4522 nested_vmx_vmexit+0x7fe/0xd90 [kvm_intel]
Modules linked in: kvm_intel kvm irqbypass
CPU: 7 PID: 1399 Comm: state_test Not tainted 5.17.0-rc3+ #808
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:nested_vmx_vmexit+0x7fe/0xd90 [kvm_intel]
Call Trace:
<TASK>
vmx_leave_nested+0x30/0x40 [kvm_intel]
vmx_set_nested_state+0xca/0x3e0 [kvm_intel]
kvm_arch_vcpu_ioctl+0xf49/0x13e0 [kvm]
kvm_vcpu_ioctl+0x4b9/0x660 [kvm]
__x64_sys_ioctl+0x83/0xb0
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
</TASK>
---[ end trace
0000000000000000 ]---
Fixes:
cb6a32c2b877 ("KVM: x86: Handle triple fault in L2 without killing L1")
Cc: stable@vger.kernel.org
Cc: Chenyi Qiang <chenyi.qiang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20220407002315.78092-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sean Christopherson [Fri, 11 Mar 2022 03:27:41 +0000 (03:27 +0000)]
KVM: x86: avoid calling x86 emulator without a decoded instruction
commit
fee060cd52d69c114b62d1a2948ea9648b5131f9 upstream.
Whenever x86_decode_emulated_instruction() detects a breakpoint, it
returns the value that kvm_vcpu_check_breakpoint() writes into its
pass-by-reference second argument. Unfortunately this is completely
bogus because the expected outcome of x86_decode_emulated_instruction
is an EMULATION_* value.
Then, if kvm_vcpu_check_breakpoint() does "*r = 0" (corresponding to
a KVM_EXIT_DEBUG userspace exit), it is misunderstood as EMULATION_OK
and x86_emulate_instruction() is called without having decoded the
instruction. This causes various havoc from running with a stale
emulation context.
The fix is to move the call to kvm_vcpu_check_breakpoint() where it was
before commit
4aa2691dcbd3 ("KVM: x86: Factor out x86 instruction
emulation with decoding") introduced x86_decode_emulated_instruction().
The other caller of the function does not need breakpoint checks,
because it is invoked as part of a vmexit and the processor has already
checked those before executing the instruction that #GP'd.
This fixes CVE-2022-1852.
Reported-by: Qiuhao Li <qiuhao@sysec.org>
Reported-by: Gaoning Pan <pgn@zju.edu.cn>
Reported-by: Yongkang Jia <kangel@zju.edu.cn>
Fixes:
4aa2691dcbd3 ("KVM: x86: Factor out x86 instruction emulation with decoding")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <
20220311032801.3467418-2-seanjc@google.com>
[Rewrote commit message according to Qiuhao's report, since a patch
already existed to fix the bug. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Paolo Bonzini [Tue, 24 May 2022 13:43:31 +0000 (09:43 -0400)]
x86, kvm: use correct GFP flags for preemption disabled
commit
baec4f5a018fe2d708fc1022330dba04b38b5fe3 upstream.
Commit
ddd7ed842627 ("x86/kvm: Alloc dummy async #PF token outside of
raw spinlock") leads to the following Smatch static checker warning:
arch/x86/kernel/kvm.c:212 kvm_async_pf_task_wake()
warn: sleeping in atomic context
arch/x86/kernel/kvm.c
202 raw_spin_lock(&b->lock);
203 n = _find_apf_task(b, token);
204 if (!n) {
205 /*
206 * Async #PF not yet handled, add a dummy entry for the token.
207 * Allocating the token must be down outside of the raw lock
208 * as the allocator is preemptible on PREEMPT_RT kernels.
209 */
210 if (!dummy) {
211 raw_spin_unlock(&b->lock);
--> 212 dummy = kzalloc(sizeof(*dummy), GFP_KERNEL);
^^^^^^^^^^
Smatch thinks the caller has preempt disabled. The `smdb.py preempt
kvm_async_pf_task_wake` output call tree is:
sysvec_kvm_asyncpf_interrupt() <- disables preempt
-> __sysvec_kvm_asyncpf_interrupt()
-> kvm_async_pf_task_wake()
The caller is this:
arch/x86/kernel/kvm.c
290 DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_asyncpf_interrupt)
291 {
292 struct pt_regs *old_regs = set_irq_regs(regs);
293 u32 token;
294
295 ack_APIC_irq();
296
297 inc_irq_stat(irq_hv_callback_count);
298
299 if (__this_cpu_read(apf_reason.enabled)) {
300 token = __this_cpu_read(apf_reason.token);
301 kvm_async_pf_task_wake(token);
302 __this_cpu_write(apf_reason.token, 0);
303 wrmsrl(MSR_KVM_ASYNC_PF_ACK, 1);
304 }
305
306 set_irq_regs(old_regs);
307 }
The DEFINE_IDTENTRY_SYSVEC() is a wrapper that calls this function
from the call_on_irqstack_cond(). It's inside the call_on_irqstack_cond()
where preempt is disabled (unless it's already disabled). The
irq_enter/exit_rcu() functions disable/enable preempt.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sean Christopherson [Thu, 19 May 2022 14:57:11 +0000 (07:57 -0700)]
x86/kvm: Alloc dummy async #PF token outside of raw spinlock
commit
0547758a6de3cc71a0cfdd031a3621a30db6a68b upstream.
Drop the raw spinlock in kvm_async_pf_task_wake() before allocating the
the dummy async #PF token, the allocator is preemptible on PREEMPT_RT
kernels and must not be called from truly atomic contexts.
Opportunistically document why it's ok to loop on allocation failure,
i.e. why the function won't get stuck in an infinite loop.
Reported-by: Yajun Deng <yajun.deng@linux.dev>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Xiaomeng Tong [Thu, 14 Apr 2022 06:21:03 +0000 (14:21 +0800)]
KVM: PPC: Book3S HV: fix incorrect NULL check on list iterator
commit
300981abddcb13f8f06ad58f52358b53a8096775 upstream.
The bug is here:
if (!p)
return ret;
The list iterator value 'p' will *always* be set and non-NULL by
list_for_each_entry(), so it is incorrect to assume that the iterator
value will be NULL if the list is empty or no element is found.
To fix the bug, Use a new value 'iter' as the list iterator, while use
the old value 'p' as a dedicated variable to point to the found element.
Fixes:
dfaa973ae960 ("KVM: PPC: Book3S HV: In H_SVM_INIT_DONE, migrate remaining normal-GFNs to secure-GFNs")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220414062103.8153-1-xiam0nd.tong@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Florian Westphal [Thu, 19 May 2022 22:02:04 +0000 (00:02 +0200)]
netfilter: conntrack: re-fetch conntrack after insertion
commit
56b14ecec97f39118bf85c9ac2438c5a949509ed upstream.
In case the conntrack is clashing, insertion can free skb->_nfct and
set skb->_nfct to the already-confirmed entry.
This wasn't found before because the conntrack entry and the extension
space used to free'd after an rcu grace period, plus the race needs
events enabled to trigger.
Reported-by: <syzbot+793a590957d9c1b96620@syzkaller.appspotmail.com>
Fixes:
71d8c47fc653 ("netfilter: conntrack: introduce clash resolution on insertion race")
Fixes:
2ad9d7747c10 ("netfilter: conntrack: free extension area immediately")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pablo Neira Ayuso [Mon, 30 May 2022 16:24:06 +0000 (18:24 +0200)]
netfilter: nf_tables: double hook unregistration in netns path
commit
f9a43007d3f7ba76d5e7f9421094f00f2ef202f8 upstream.
__nft_release_hooks() is called from pre_netns exit path which
unregisters the hooks, then the NETDEV_UNREGISTER event is triggered
which unregisters the hooks again.
[ 565.221461] WARNING: CPU: 18 PID: 193 at net/netfilter/core.c:495 __nf_unregister_net_hook+0x247/0x270
[...]
[ 565.246890] CPU: 18 PID: 193 Comm: kworker/u64:1 Tainted: G E 5.18.0-rc7+ #27
[ 565.253682] Workqueue: netns cleanup_net
[ 565.257059] RIP: 0010:__nf_unregister_net_hook+0x247/0x270
[...]
[ 565.297120] Call Trace:
[ 565.300900] <TASK>
[ 565.304683] nf_tables_flowtable_event+0x16a/0x220 [nf_tables]
[ 565.308518] raw_notifier_call_chain+0x63/0x80
[ 565.312386] unregister_netdevice_many+0x54f/0xb50
Unregister and destroy netdev hook from netns pre_exit via kfree_rcu
so the NETDEV_UNREGISTER path see unregistered hooks.
Fixes:
767d1216bff8 ("netfilter: nftables: fix possible UAF over chains from packet path in netns")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pablo Neira Ayuso [Mon, 30 May 2022 16:24:05 +0000 (18:24 +0200)]
netfilter: nf_tables: hold mutex on netns pre_exit path
commit
3923b1e4406680d57da7e873da77b1683035d83f upstream.
clean_net() runs in workqueue while walking over the lists, grab mutex.
Fixes:
767d1216bff8 ("netfilter: nftables: fix possible UAF over chains from packet path in netns")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pablo Neira Ayuso [Fri, 27 May 2022 07:56:18 +0000 (09:56 +0200)]
netfilter: nf_tables: sanitize nft_set_desc_concat_parse()
commit
fecf31ee395b0295f2d7260aa29946b7605f7c85 upstream.
Add several sanity checks for nft_set_desc_concat_parse():
- validate desc->field_count not larger than desc->field_len array.
- field length cannot be larger than desc->field_len (ie. U8_MAX)
- total length of the concatenation cannot be larger than register array.
Joint work with Florian Westphal.
Fixes:
f3a2181e16f1 ("netfilter: nf_tables: Support for sets with multiple ranged fields")
Reported-by: <zhangziming.zzm@antgroup.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stange [Thu, 2 Jun 2022 20:23:27 +0000 (22:23 +0200)]
crypto: drbg - make reseeding from get_random_bytes() synchronous
commit
074bcd4000e0d812bc253f86fedc40f81ed59ccc upstream.
get_random_bytes() usually hasn't full entropy available by the time DRBG
instances are first getting seeded from it during boot. Thus, the DRBG
implementation registers random_ready_callbacks which would in turn
schedule some work for reseeding the DRBGs once get_random_bytes() has
sufficient entropy available.
For reference, the relevant history around handling DRBG (re)seeding in
the context of a not yet fully seeded get_random_bytes() is:
commit
16b369a91d0d ("random: Blocking API for accessing
nonblocking_pool")
commit
4c7879907edd ("crypto: drbg - add async seeding operation")
commit
205a525c3342 ("random: Add callback API for random pool
readiness")
commit
57225e679788 ("crypto: drbg - Use callback API for random
readiness")
commit
c2719503f5e1 ("random: Remove kernel blocking API")
However, some time later, the initialization state of get_random_bytes()
has been made queryable via rng_is_initialized() introduced with commit
9a47249d444d ("random: Make crng state queryable"). This primitive now
allows for streamlining the DRBG reseeding from get_random_bytes() by
replacing that aforementioned asynchronous work scheduling from
random_ready_callbacks with some simpler, synchronous code in
drbg_generate() next to the related logic already present therein. Apart
from improving overall code readability, this change will also enable DRBG
users to rely on wait_for_random_bytes() for ensuring that the initial
seeding has completed, if desired.
The previous patches already laid the grounds by making drbg_seed() to
record at each DRBG instance whether it was being seeded at a time when
rng_is_initialized() still had been false as indicated by
->seeded == DRBG_SEED_STATE_PARTIAL.
All that remains to be done now is to make drbg_generate() check for this
condition, determine whether rng_is_initialized() has flipped to true in
the meanwhile and invoke a reseed from get_random_bytes() if so.
Make this move:
- rename the former drbg_async_seed() work handler, i.e. the one in charge
of reseeding a DRBG instance from get_random_bytes(), to
"drbg_seed_from_random()",
- change its signature as appropriate, i.e. make it take a struct
drbg_state rather than a work_struct and change its return type from
"void" to "int" in order to allow for passing error information from
e.g. its __drbg_seed() invocation onwards to callers,
- make drbg_generate() invoke this drbg_seed_from_random() once it
encounters a DRBG instance with ->seeded == DRBG_SEED_STATE_PARTIAL by
the time rng_is_initialized() has flipped to true and
- prune everything related to the former, random_ready_callback based
mechanism.
As drbg_seed_from_random() is now getting invoked from drbg_generate() with
the ->drbg_mutex being held, it must not attempt to recursively grab it
once again. Remove the corresponding mutex operations from what is now
drbg_seed_from_random(). Furthermore, as drbg_seed_from_random() can now
report errors directly to its caller, there's no need for it to temporarily
switch the DRBG's ->seeded state to DRBG_SEED_STATE_UNSEEDED so that a
failure of the subsequently invoked __drbg_seed() will get signaled to
drbg_generate(). Don't do it then.
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
[Jason: for stable, undid the modifications for the backport of
5acd3548.]
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stange [Thu, 2 Jun 2022 20:23:26 +0000 (22:23 +0200)]
crypto: drbg - move dynamic ->reseed_threshold adjustments to __drbg_seed()
commit
262d83a4290c331cd4f617a457408bdb82fbb738 upstream.
Since commit
42ea507fae1a ("crypto: drbg - reseed often if seedsource is
degraded"), the maximum seed lifetime represented by ->reseed_threshold
gets temporarily lowered if the get_random_bytes() source cannot provide
sufficient entropy yet, as is common during boot, and restored back to
the original value again once that has changed.
More specifically, if the add_random_ready_callback() invoked from
drbg_prepare_hrng() in the course of DRBG instantiation does not return
-EALREADY, that is, if get_random_bytes() has not been fully initialized
at this point yet, drbg_prepare_hrng() will lower ->reseed_threshold
to a value of 50. The drbg_async_seed() scheduled from said
random_ready_callback will eventually restore the original value.
A future patch will replace the random_ready_callback based notification
mechanism and thus, there will be no add_random_ready_callback() return
value anymore which could get compared to -EALREADY.
However, there's __drbg_seed() which gets invoked in the course of both,
the DRBG instantiation as well as the eventual reseeding from
get_random_bytes() in aforementioned drbg_async_seed(), if any. Moreover,
it knows about the get_random_bytes() initialization state by the time the
seed data had been obtained from it: the new_seed_state argument introduced
with the previous patch would get set to DRBG_SEED_STATE_PARTIAL in case
get_random_bytes() had not been fully initialized yet and to
DRBG_SEED_STATE_FULL otherwise. Thus, __drbg_seed() provides a convenient
alternative for managing that ->reseed_threshold lowering and restoring at
a central place.
Move all ->reseed_threshold adjustment code from drbg_prepare_hrng() and
drbg_async_seed() respectively to __drbg_seed(). Make __drbg_seed()
lower the ->reseed_threshold to 50 in case its new_seed_state argument
equals DRBG_SEED_STATE_PARTIAL and let it restore the original value
otherwise.
There is no change in behaviour.
Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stange [Thu, 2 Jun 2022 20:23:25 +0000 (22:23 +0200)]
crypto: drbg - track whether DRBG was seeded with !rng_is_initialized()
commit
2bcd25443868aa8863779a6ebc6c9319633025d2 upstream.
Currently, the DRBG implementation schedules asynchronous works from
random_ready_callbacks for reseeding the DRBG instances with output from
get_random_bytes() once the latter has sufficient entropy available.
However, as the get_random_bytes() initialization state can get queried by
means of rng_is_initialized() now, there is no real need for this
asynchronous reseeding logic anymore and it's better to keep things simple
by doing it synchronously when needed instead, i.e. from drbg_generate()
once rng_is_initialized() has flipped to true.
Of course, for this to work, drbg_generate() would need some means by which
it can tell whether or not rng_is_initialized() has flipped to true since
the last seeding from get_random_bytes(). Or equivalently, whether or not
the last seed from get_random_bytes() has happened when
rng_is_initialized() was still evaluating to false.
As it currently stands, enum drbg_seed_state allows for the representation
of two different DRBG seeding states: DRBG_SEED_STATE_UNSEEDED and
DRBG_SEED_STATE_FULL. The former makes drbg_generate() to invoke a full
reseeding operation involving both, the rather expensive jitterentropy as
well as the get_random_bytes() randomness sources. The DRBG_SEED_STATE_FULL
state on the other hand implies that no reseeding at all is required for a
!->pr DRBG variant.
Introduce the new DRBG_SEED_STATE_PARTIAL state to enum drbg_seed_state for
representing the condition that a DRBG was being seeded when
rng_is_initialized() had still been false. In particular, this new state
implies that
- the given DRBG instance has been fully seeded from the jitterentropy
source (if enabled)
- and drbg_generate() is supposed to reseed from get_random_bytes()
*only* once rng_is_initialized() turns to true.
Up to now, the __drbg_seed() helper used to set the given DRBG instance's
->seeded state to constant DRBG_SEED_STATE_FULL. Introduce a new argument
allowing for the specification of the to be written ->seeded value instead.
Make the first of its two callers, drbg_seed(), determine the appropriate
value based on rng_is_initialized(). The remaining caller,
drbg_async_seed(), is known to get invoked only once rng_is_initialized()
is true, hence let it pass constant DRBG_SEED_STATE_FULL for the new
argument to __drbg_seed().
There is no change in behaviour, except for that the pr_devel() in
drbg_generate() would now report "unseeded" for ->pr DRBG instances which
had last been seeded when rng_is_initialized() was still evaluating to
false.
Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stange [Thu, 2 Jun 2022 20:23:24 +0000 (22:23 +0200)]
crypto: drbg - prepare for more fine-grained tracking of seeding state
commit
ce8ce31b2c5c8b18667784b8c515650c65d57b4e upstream.
There are two different randomness sources the DRBGs are getting seeded
from, namely the jitterentropy source (if enabled) and get_random_bytes().
At initial DRBG seeding time during boot, the latter might not have
collected sufficient entropy for seeding itself yet and thus, the DRBG
implementation schedules a reseed work from a random_ready_callback once
that has happened. This is particularly important for the !->pr DRBG
instances, for which (almost) no further reseeds are getting triggered
during their lifetime.
Because collecting data from the jitterentropy source is a rather expensive
operation, the aforementioned asynchronously scheduled reseed work
restricts itself to get_random_bytes() only. That is, it in some sense
amends the initial DRBG seed derived from jitterentropy output at full
(estimated) entropy with fresh randomness obtained from get_random_bytes()
once that has been seeded with sufficient entropy itself.
With the advent of rng_is_initialized(), there is no real need for doing
the reseed operation from an asynchronously scheduled work anymore and a
subsequent patch will make it synchronous by moving it next to related
logic already present in drbg_generate().
However, for tracking whether a full reseed including the jitterentropy
source is required or a "partial" reseed involving only get_random_bytes()
would be sufficient already, the boolean struct drbg_state's ->seeded
member must become a tristate value.
Prepare for this by introducing the new enum drbg_seed_state and change
struct drbg_state's ->seeded member's type from bool to that type.
For facilitating review, enum drbg_seed_state is made to only contain
two members corresponding to the former ->seeded values of false and true
resp. at this point: DRBG_SEED_STATE_UNSEEDED and DRBG_SEED_STATE_FULL. A
third one for tracking the intermediate state of "seeded from jitterentropy
only" will be introduced with a subsequent patch.
There is no change in behaviour at this point.
Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Justin M. Forbes [Thu, 2 Jun 2022 20:23:23 +0000 (22:23 +0200)]
lib/crypto: add prompts back to crypto libraries
commit
e56e18985596617ae426ed5997fb2e737cffb58b upstream.
Commit
6048fdcc5f269 ("lib/crypto: blake2s: include as built-in") took
away a number of prompt texts from other crypto libraries. This makes
values flip from built-in to module when oldconfig runs, and causes
problems when these crypto libs need to be built in for thingslike
BIG_KEYS.
Fixes:
6048fdcc5f269 ("lib/crypto: blake2s: include as built-in")
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Justin M. Forbes <jforbes@fedoraproject.org>
[Jason: - moved menu into submenu of lib/ instead of root menu
- fixed chacha sub-dependencies for CONFIG_CRYPTO]
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tadeusz Struk [Mon, 16 May 2022 23:13:08 +0000 (08:13 +0900)]
exfat: check if cluster num is valid
commit
64ba4b15e5c045f8b746c6da5fc9be9a6b00b61d upstream.
Syzbot reported slab-out-of-bounds read in exfat_clear_bitmap.
This was triggered by reproducer calling truncute with size 0,
which causes the following trace:
BUG: KASAN: slab-out-of-bounds in exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174
Read of size 8 at addr
ffff888115aa9508 by task syz-executor251/365
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
print_address_description+0x81/0x3c0 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report+0x1a4/0x1f0 mm/kasan/report.c:436
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174
exfat_free_cluster+0x25a/0x4a0 fs/exfat/fatent.c:181
__exfat_truncate+0x99e/0xe00 fs/exfat/file.c:217
exfat_truncate+0x11b/0x4f0 fs/exfat/file.c:243
exfat_setattr+0xa03/0xd40 fs/exfat/file.c:339
notify_change+0xb76/0xe10 fs/attr.c:336
do_truncate+0x1ea/0x2d0 fs/open.c:65
Move the is_valid_cluster() helper from fatent.c to a common
header to make it reusable in other *.c files. And add is_valid_cluster()
to validate if cluster number is within valid range in exfat_clear_bitmap()
and exfat_set_bitmap().
Link: https://syzkaller.appspot.com/bug?id=50381fc73821ecae743b8cf24b4c9a04776f767c
Reported-by: syzbot+a4087e40b9c13aad7892@syzkaller.appspotmail.com
Fixes:
1e49a94cf707 ("exfat: add bitmap operations")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Gustavo A. R. Silva [Wed, 27 Apr 2022 22:47:14 +0000 (17:47 -0500)]
drm/i915: Fix -Wstringop-overflow warning in call to intel_read_wm_latency()
commit
336feb502a715909a8136eb6a62a83d7268a353b upstream.
Fix the following -Wstringop-overflow warnings when building with GCC-11:
drivers/gpu/drm/i915/intel_pm.c:3106:9: warning: ‘intel_read_wm_latency’ accessing 16 bytes in a region of size 10 [-Wstringop-overflow=]
3106 | intel_read_wm_latency(dev_priv, dev_priv->wm.pri_latency);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/i915/intel_pm.c:3106:9: note: referencing argument 2 of type ‘u16 *’ {aka ‘short unsigned int *’}
drivers/gpu/drm/i915/intel_pm.c:2861:13: note: in a call to function ‘intel_read_wm_latency’
2861 | static void intel_read_wm_latency(struct drm_i915_private *dev_priv,
| ^~~~~~~~~~~~~~~~~~~~~
by removing the over-specified array size from the argument declarations.
It seems that this code is actually safe because the size of the
array depends on the hardware generation, and the function checks
for that.
Notice that wm can be an array of 5 elements:
drivers/gpu/drm/i915/intel_pm.c:3109: intel_read_wm_latency(dev_priv, dev_priv->wm.pri_latency);
or an array of 8 elements:
drivers/gpu/drm/i915/intel_pm.c:3131: intel_read_wm_latency(dev_priv, dev_priv->wm.skl_latency);
and the compiler legitimately complains about that.
This helps with the ongoing efforts to globally enable
-Wstringop-overflow.
Link: https://github.com/KSPP/linux/issues/181
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Alex Elder [Thu, 21 Apr 2022 18:53:33 +0000 (13:53 -0500)]
net: ipa: compute proper aggregation limit
commit
c5794097b269f15961ed78f7f27b50e51766dec9 upstream.
The aggregation byte limit for an endpoint is currently computed
based on the endpoint's receive buffer size.
However, some bytes at the front of each receive buffer are reserved
on the assumption that--as with SKBs--it might be useful to insert
data (such as headers) before what lands in the buffer.
The aggregation byte limit currently doesn't take into account that
reserved space, and as a result, aggregation could require space
past that which is available in the buffer.
Fix this by reducing the size used to compute the aggregation byte
limit by the NET_SKB_PAD offset reserved for each receive buffer.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
David Howells [Thu, 26 May 2022 06:34:52 +0000 (07:34 +0100)]
pipe: Fix missing lock in pipe_resize_ring()
commit
189b0ddc245139af81198d1a3637cac74f96e13a upstream.
pipe_resize_ring() needs to take the pipe->rd_wait.lock spinlock to
prevent post_one_notification() from trying to insert into the ring
whilst the ring is being replaced.
The occupancy check must be done after the lock is taken, and the lock
must be taken after the new ring is allocated.
The bug can lead to an oops looking something like:
BUG: KASAN: use-after-free in post_one_notification.isra.0+0x62e/0x840
Read of size 4 at addr
ffff88801cc72a70 by task poc/27196
...
Call Trace:
post_one_notification.isra.0+0x62e/0x840
__post_watch_notification+0x3b7/0x650
key_create_or_update+0xb8b/0xd20
__do_sys_add_key+0x175/0x340
__x64_sys_add_key+0xbe/0x140
do_syscall_64+0x5c/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Reported by Selim Enes Karaduman @Enesdex working with Trend Micro Zero
Day Initiative.
Fixes:
c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17291
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kuniyuki Iwashima [Fri, 29 Apr 2022 21:38:01 +0000 (14:38 -0700)]
pipe: make poll_usage boolean and annotate its access
commit
f485922d8fe4e44f6d52a5bb95a603b7c65554bb upstream.
Patch series "Fix data-races around epoll reported by KCSAN."
This series suppresses a false positive KCSAN's message and fixes a real
data-race.
This patch (of 2):
pipe_poll() runs locklessly and assigns 1 to poll_usage. Once poll_usage
is set to 1, it never changes in other places. However, concurrent writes
of a value trigger KCSAN, so let's make KCSAN happy.
BUG: KCSAN: data-race in pipe_poll / pipe_poll
write to 0xffff8880042f6678 of 4 bytes by task 174 on cpu 3:
pipe_poll (fs/pipe.c:656)
ep_item_poll.isra.0 (./include/linux/poll.h:88 fs/eventpoll.c:853)
do_epoll_wait (fs/eventpoll.c:1692 fs/eventpoll.c:1806 fs/eventpoll.c:2234)
__x64_sys_epoll_wait (fs/eventpoll.c:2246 fs/eventpoll.c:2241 fs/eventpoll.c:2241)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)
write to 0xffff8880042f6678 of 4 bytes by task 177 on cpu 1:
pipe_poll (fs/pipe.c:656)
ep_item_poll.isra.0 (./include/linux/poll.h:88 fs/eventpoll.c:853)
do_epoll_wait (fs/eventpoll.c:1692 fs/eventpoll.c:1806 fs/eventpoll.c:2234)
__x64_sys_epoll_wait (fs/eventpoll.c:2246 fs/eventpoll.c:2241 fs/eventpoll.c:2241)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 177 Comm: epoll_race Not tainted 5.17.0-58927-gf443e374ae13 #6
Hardware name: Red Hat KVM, BIOS 1.11.0-2.amzn2 04/01/2014
Link: https://lkml.kernel.org/r/20220322002653.33865-1-kuniyu@amazon.co.jp
Link: https://lkml.kernel.org/r/20220322002653.33865-2-kuniyu@amazon.co.jp
Fixes:
3b844826b6c6 ("pipe: avoid unnecessary EPOLLET wakeups under normal loads")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kuniyuki Iwashima <kuni1840@gmail.com>
Cc: "Soheil Hassas Yeganeh" <soheil@google.com>
Cc: "Sridhar Samudrala" <sridhar.samudrala@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stephen Brennan [Thu, 19 May 2022 08:50:30 +0000 (09:50 +0100)]
assoc_array: Fix BUG_ON during garbage collect
commit
d1dc87763f406d4e67caf16dbe438a5647692395 upstream.
A rare BUG_ON triggered in assoc_array_gc:
[3430308.818153] kernel BUG at lib/assoc_array.c:1609!
Which corresponded to the statement currently at line 1593 upstream:
BUG_ON(assoc_array_ptr_is_meta(p));
Using the data from the core dump, I was able to generate a userspace
reproducer[1] and determine the cause of the bug.
[1]: https://github.com/brenns10/kernel_stuff/tree/master/assoc_array_gc
After running the iterator on the entire branch, an internal tree node
looked like the following:
NODE (nr_leaves_on_branch: 3)
SLOT [0] NODE (2 leaves)
SLOT [1] NODE (1 leaf)
SLOT [2..f] NODE (empty)
In the userspace reproducer, the pr_devel output when compressing this
node was:
-- compress node 0x5607cc089380 --
free=0, leaves=0
[0] retain node 2/1 [nx 0]
[1] fold node 1/1 [nx 0]
[2] fold node 0/1 [nx 2]
[3] fold node 0/2 [nx 2]
[4] fold node 0/3 [nx 2]
[5] fold node 0/4 [nx 2]
[6] fold node 0/5 [nx 2]
[7] fold node 0/6 [nx 2]
[8] fold node 0/7 [nx 2]
[9] fold node 0/8 [nx 2]
[10] fold node 0/9 [nx 2]
[11] fold node 0/10 [nx 2]
[12] fold node 0/11 [nx 2]
[13] fold node 0/12 [nx 2]
[14] fold node 0/13 [nx 2]
[15] fold node 0/14 [nx 2]
after: 3
At slot 0, an internal node with 2 leaves could not be folded into the
node, because there was only one available slot (slot 0). Thus, the
internal node was retained. At slot 1, the node had one leaf, and was
able to be folded in successfully. The remaining nodes had no leaves,
and so were removed. By the end of the compression stage, there were 14
free slots, and only 3 leaf nodes. The tree was ascended and then its
parent node was compressed. When this node was seen, it could not be
folded, due to the internal node it contained.
The invariant for compression in this function is: whenever
nr_leaves_on_branch < ASSOC_ARRAY_FAN_OUT, the node should contain all
leaf nodes. The compression step currently cannot guarantee this, given
the corner case shown above.
To fix this issue, retry compression whenever we have retained a node,
and yet nr_leaves_on_branch < ASSOC_ARRAY_FAN_OUT. This second
compression will then allow the node in slot 1 to be folded in,
satisfying the invariant. Below is the output of the reproducer once the
fix is applied:
-- compress node 0x560e9c562380 --
free=0, leaves=0
[0] retain node 2/1 [nx 0]
[1] fold node 1/1 [nx 0]
[2] fold node 0/1 [nx 2]
[3] fold node 0/2 [nx 2]
[4] fold node 0/3 [nx 2]
[5] fold node 0/4 [nx 2]
[6] fold node 0/5 [nx 2]
[7] fold node 0/6 [nx 2]
[8] fold node 0/7 [nx 2]
[9] fold node 0/8 [nx 2]
[10] fold node 0/9 [nx 2]
[11] fold node 0/10 [nx 2]
[12] fold node 0/11 [nx 2]
[13] fold node 0/12 [nx 2]
[14] fold node 0/13 [nx 2]
[15] fold node 0/14 [nx 2]
internal nodes remain despite enough space, retrying
-- compress node 0x560e9c562380 --
free=14, leaves=1
[0] fold node 2/15 [nx 0]
after: 3
Changes
=======
DH:
- Use false instead of 0.
- Reorder the inserted lines in a couple of places to put retained before
next_slot.
ver #2)
- Fix typo in pr_devel, correct comparison to "<="
Fixes:
3cb989501c26 ("Add a generic associative array implementation.")
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: keyrings@vger.kernel.org
Link: https://lore.kernel.org/r/20220511225517.407935-1-stephen.s.brennan@oracle.com/
Link: https://lore.kernel.org/r/20220512215045.489140-1-stephen.s.brennan@oracle.com/
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dan Carpenter [Thu, 2 Jun 2022 11:02:18 +0000 (14:02 +0300)]
i2c: ismt: prevent memory corruption in ismt_access()
commit
690b2549b19563ec5ad53e5c82f6a944d910086e upstream.
The "data->block[0]" variable comes from the user and is a number
between 0-255. It needs to be capped to prevent writing beyond the end
of dma_buffer[].
Fixes:
5e9a97b1f449 ("i2c: ismt: Adding support for I2C_SMBUS_BLOCK_PROC_CALL")
Reported-and-tested-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pablo Neira Ayuso [Wed, 25 May 2022 08:36:38 +0000 (10:36 +0200)]
netfilter: nf_tables: disallow non-stateful expression in sets earlier
commit
520778042ccca019f3ffa136dd0ca565c486cedd upstream.
Since
3e135cd499bf ("netfilter: nft_dynset: dynamic stateful expression
instantiation"), it is possible to attach stateful expressions to set
elements.
cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate
and destroy phase") introduces conditional destruction on the object to
accomodate transaction semantics.
nft_expr_init() calls expr->ops->init() first, then check for
NFT_STATEFUL_EXPR, this stills allows to initialize a non-stateful
lookup expressions which points to a set, which might lead to UAF since
the set is not properly detached from the set->binding for this case.
Anyway, this combination is non-sense from nf_tables perspective.
This patch fixes this problem by checking for NFT_STATEFUL_EXPR before
expr->ops->init() is called.
The reporter provides a KASAN splat and a poc reproducer (similar to
those autogenerated by syzbot to report use-after-free errors). It is
unknown to me if they are using syzbot or if they use similar automated
tool to locate the bug that they are reporting.
For the record, this is the KASAN splat.
[ 85.431824] ==================================================================
[ 85.432901] BUG: KASAN: use-after-free in nf_tables_bind_set+0x81b/0xa20
[ 85.433825] Write of size 8 at addr
ffff8880286f0e98 by task poc/776
[ 85.434756]
[ 85.434999] CPU: 1 PID: 776 Comm: poc Tainted: G W 5.18.0+ #2
[ 85.436023] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Fixes:
0b2d8a7b638b ("netfilter: nf_tables: add helper functions for expression handling")
Reported-and-tested-by: Aaron Adams <edg-e@nccgroup.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Piyush Malgujar [Wed, 11 May 2022 13:36:59 +0000 (06:36 -0700)]
drivers: i2c: thunderx: Allow driver to work with ACPI defined TWSI controllers
[ Upstream commit
03a35bc856ddc09f2cc1f4701adecfbf3b464cb3 ]
Due to i2c->adap.dev.fwnode not being set, ACPI_COMPANION() wasn't properly
found for TWSI controllers.
Signed-off-by: Szymon Balcerak <sbalcerak@marvell.com>
Signed-off-by: Piyush Malgujar <pmalgujar@marvell.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Mika Westerberg [Wed, 27 Apr 2022 10:19:10 +0000 (13:19 +0300)]
i2c: ismt: Provide a DMA buffer for Interrupt Cause Logging
[ Upstream commit
17a0f3acdc6ec8b89ad40f6e22165a4beee25663 ]
Before sending a MSI the hardware writes information pertinent to the
interrupt cause to a memory location pointed by SMTICL register. This
memory holds three double words where the least significant bit tells
whether the interrupt cause of master/target/error is valid. The driver
does not use this but we need to set it up because otherwise it will
perform DMA write to the default address (0) and this will cause an
IOMMU fault such as below:
DMAR: DRHD: handling fault status reg 2
DMAR: [DMA Write] Request device [00:12.0] PASID
ffffffff fault addr 0
[fault reason 05] PTE Write access is not set
To prevent this from happening, provide a proper DMA buffer for this
that then gets mapped by the IOMMU accordingly.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Joel Stanley [Tue, 17 May 2022 09:22:17 +0000 (18:52 +0930)]
net: ftgmac100: Disable hardware checksum on AST2600
[ Upstream commit
6fd45e79e8b93b8d22fb8fe22c32fbad7e9190bd ]
The AST2600 when using the i210 NIC over NC-SI has been observed to
produce incorrect checksum results with specific MTU values. This was
first observed when sending data across a long distance set of networks.
On a local network, the following test was performed using a 1MB file of
random data.
On the receiver run this script:
#!/bin/bash
while [ 1 ]; do
# Zero the stats
nstat -r > /dev/null
nc -l 9899 > test-file
# Check for checksum errors
TcpInCsumErrors=$(nstat | grep TcpInCsumErrors)
if [ -z "$TcpInCsumErrors" ]; then
echo No TcpInCsumErrors
else
echo TcpInCsumErrors = $TcpInCsumErrors
fi
done
On an AST2600 system:
# nc <IP of receiver host> 9899 < test-file
The test was repeated with various MTU values:
# ip link set mtu 1410 dev eth0
The observed results:
1500 - good
1434 - bad
1400 - good
1410 - bad
1420 - good
The test was repeated after disabling tx checksumming:
# ethtool -K eth0 tx-checksumming off
And all MTU values tested resulted in transfers without error.
An issue with the driver cannot be ruled out, however there has been no
bug discovered so far.
David has done the work to take the original bug report of slow data
transfer between long distance connections and triaged it down to this
test case.
The vendor suspects this this is a hardware issue when using NC-SI. The
fixes line refers to the patch that introduced AST2600 support.
Reported-by: David Wilder <wilder@us.ibm.com>
Reviewed-by: Dylan Hung <dylan_hung@aspeedtech.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Lin Ma [Wed, 18 May 2022 10:53:21 +0000 (18:53 +0800)]
nfc: pn533: Fix buggy cleanup order
[ Upstream commit
b8cedb7093b2d1394cae9b86494cba4b62d3a30a ]
When removing the pn533 device (i2c or USB), there is a logic error. The
original code first cancels the worker (flush_delayed_work) and then
destroys the workqueue (destroy_workqueue), leaving the timer the last
one to be deleted (del_timer). This result in a possible race condition
in a multi-core preempt-able kernel. That is, if the cleanup
(pn53x_common_clean) is concurrently run with the timer handler
(pn533_listen_mode_timer), the timer can queue the poll_work to the
already destroyed workqueue, causing use-after-free.
This patch reorder the cleanup: it uses the del_timer_sync to make sure
the handler is finished before the routine will destroy the workqueue.
Note that the timer cannot be activated by the worker again.
static void pn533_wq_poll(struct work_struct *work)
...
rc = pn533_send_poll_frame(dev);
if (rc)
return;
if (cur_mod->len == 0 && dev->poll_mod_count > 1)
mod_timer(&dev->listen_timer, ...);
That is, the mod_timer can be called only when pn533_send_poll_frame()
returns no error, which is impossible because the device is detaching
and the lower driver should return ENODEV code.
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Thomas Bartschies [Wed, 18 May 2022 06:32:18 +0000 (08:32 +0200)]
net: af_key: check encryption module availability consistency
[ Upstream commit
015c44d7bff3f44d569716117becd570c179ca32 ]
Since the recent introduction supporting the SM3 and SM4 hash algos for IPsec, the kernel
produces invalid pfkey acquire messages, when these encryption modules are disabled. This
happens because the availability of the algos wasn't checked in all necessary functions.
This patch adds these checks.
Signed-off-by: Thomas Bartschies <thomas.bartschies@cvk.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Al Viro [Wed, 18 May 2022 06:13:40 +0000 (02:13 -0400)]
percpu_ref_init(): clean ->percpu_count_ref on failure
[ Upstream commit
a91714312eb16f9ecd1f7f8b3efe1380075f28d4 ]
That way percpu_ref_exit() is safe after failing percpu_ref_init().
At least one user (cgroup_create()) had a double-free that way;
there might be other similar bugs. Easier to fix in percpu_ref_init(),
rather than playing whack-a-mole in sloppy users...
Usual symptoms look like a messed refcounting in one of subsystems
that use percpu allocations (might be percpu-refcount, might be
something else). Having refcounts for two different objects share
memory is Not Nice(tm)...
Reported-by: syzbot+5b1e53987f858500ec00@syzkaller.appspotmail.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Quentin Perret [Fri, 13 May 2022 09:26:07 +0000 (09:26 +0000)]
KVM: arm64: Don't hypercall before EL2 init
[ Upstream commit
2e40316753ee552fb598e8da8ca0d20a04e67453 ]
Will reported the following splat when running with Protected KVM
enabled:
[ 2.427181] ------------[ cut here ]------------
[ 2.427668] WARNING: CPU: 3 PID: 1 at arch/arm64/kvm/mmu.c:489 __create_hyp_private_mapping+0x118/0x1ac
[ 2.428424] Modules linked in:
[ 2.429040] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc2-00084-g8635adc4efc7 #1
[ 2.429589] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
[ 2.430286] pstate:
80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 2.430734] pc : __create_hyp_private_mapping+0x118/0x1ac
[ 2.431091] lr : create_hyp_exec_mappings+0x40/0x80
[ 2.431377] sp :
ffff80000803baf0
[ 2.431597] x29:
ffff80000803bb00 x28:
0000000000000000 x27:
0000000000000000
[ 2.432156] x26:
0000000000000000 x25:
0000000000000000 x24:
0000000000000000
[ 2.432561] x23:
ffffcd96c343b000 x22:
0000000000000000 x21:
ffff80000803bb40
[ 2.433004] x20:
0000000000000004 x19:
0000000000001800 x18:
0000000000000000
[ 2.433343] x17:
0003e68cf7efdd70 x16:
0000000000000004 x15:
fffffc81f602a2c8
[ 2.434053] x14:
ffffdf8380000000 x13:
ffffcd9573200000 x12:
ffffcd96c343b000
[ 2.434401] x11:
0000000000000004 x10:
ffffcd96c1738000 x9 :
0000000000000004
[ 2.434812] x8 :
ffff80000803bb40 x7 :
7f7f7f7f7f7f7f7f x6 :
544f422effff306b
[ 2.435136] x5 :
000000008020001e x4 :
ffff207d80a88c00 x3 :
0000000000000005
[ 2.435480] x2 :
0000000000001800 x1 :
000000014f4ab800 x0 :
000000000badca11
[ 2.436149] Call trace:
[ 2.436600] __create_hyp_private_mapping+0x118/0x1ac
[ 2.437576] create_hyp_exec_mappings+0x40/0x80
[ 2.438180] kvm_init_vector_slots+0x180/0x194
[ 2.458941] kvm_arch_init+0x80/0x274
[ 2.459220] kvm_init+0x48/0x354
[ 2.459416] arm_init+0x20/0x2c
[ 2.459601] do_one_initcall+0xbc/0x238
[ 2.459809] do_initcall_level+0x94/0xb4
[ 2.460043] do_initcalls+0x54/0x94
[ 2.460228] do_basic_setup+0x1c/0x28
[ 2.460407] kernel_init_freeable+0x110/0x178
[ 2.460610] kernel_init+0x20/0x1a0
[ 2.460817] ret_from_fork+0x10/0x20
[ 2.461274] ---[ end trace
0000000000000000 ]---
Indeed, the Protected KVM mode promotes __create_hyp_private_mapping()
to a hypercall as EL1 no longer has access to the hypervisor's stage-1
page-table. However, the call from kvm_init_vector_slots() happens after
pKVM has been initialized on the primary CPU, but before it has been
initialized on secondaries. As such, if the KVM initcall procedure is
migrated from one CPU to another in this window, the hypercall may end up
running on a CPU for which EL2 has not been initialized.
Fortunately, the pKVM hypervisor doesn't rely on the host to re-map the
vectors in the private range, so the hypercall in question is in fact
superfluous. Skip it when pKVM is enabled.
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
[maz: simplified the checks slightly]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220513092607.35233-1-qperret@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
IotaHydrae [Wed, 4 May 2022 11:59:04 +0000 (19:59 +0800)]
pinctrl: sunxi: fix f1c100s uart2 function
[ Upstream commit
fa8785e5931367e2b43f2c507f26bcf3e281c0ca ]
Change suniv f1c100s pinctrl,PD14 multiplexing function lvds1 to uart2
When the pin PD13 and PD14 is setting up to uart2 function in dts,
there's an error occurred:
1c20800.pinctrl: unsupported function uart2 on pin PD14
Because 'uart2' is not any one multiplexing option of PD14,
and pinctrl don't know how to configure it.
So change the pin PD14 lvds1 function to uart2.
Signed-off-by: IotaHydrae <writeforever@foxmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/tencent_70C1308DDA794C81CAEF389049055BACEC09@qq.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Forest Crossman [Wed, 4 May 2022 00:24:44 +0000 (19:24 -0500)]
ALSA: usb-audio: Don't get sample rate for MCT Trigger 5 USB-to-HDMI
[ Upstream commit
d7be213849232a2accb219d537edf056d29186b4 ]
This device doesn't support reading the sample rate, so we need to apply
this quirk to avoid a 15-second delay waiting for three timeouts.
Signed-off-by: Forest Crossman <cyrozap@gmail.com>
Link: https://lore.kernel.org/r/20220504002444.114011-2-cyrozap@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Greg Kroah-Hartman [Mon, 30 May 2022 07:29:18 +0000 (09:29 +0200)]
Linux 5.15.44
Link: https://lore.kernel.org/r/20220527084850.364560116@linuxfoundation.org
Tested-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Edward Matijevic [Sat, 21 May 2022 04:45:15 +0000 (23:45 -0500)]
ALSA: ctxfi: Add SB046x PCI ID
commit
1b073ebb174d0c7109b438e0a5eb4495137803ec upstream.
Adds the PCI ID for X-Fi cards sold under the Platnum and XtremeMusic names
Before: snd_ctxfi 0000:05:05.0: chip 20K1 model Unknown (1102:0021) is found
After: snd_ctxfi 0000:05:05.0: chip 20K1 model SB046x (1102:0021) is found
[ This is only about defining the model name string, and the rest is
handled just like before, as a default unknown device.
Edward confirmed that the stuff has been working fine -- tiwai ]
Signed-off-by: Edward Matijevic <motolav@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/cae7d1a4-8bd9-7dfe-7427-db7e766f7272@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sun, 22 May 2022 20:25:41 +0000 (22:25 +0200)]
random: check for signals after page of pool writes
commit
1ce6c8d68f8ac587f54d0a271ac594d3d51f3efb upstream.
get_random_bytes_user() checks for signals after producing a PAGE_SIZE
worth of output, just like /dev/zero does. write_pool() is doing
basically the same work (actually, slightly more expensive), and so
should stop to check for signals in the same way. Let's also name it
write_pool_user() to match get_random_bytes_user(), so this won't be
misused in the future.
Before this patch, massive writes to /dev/urandom would tie up the
process for an extremely long time and make it unterminatable. After, it
can be successfully interrupted. The following test program can be used
to see this works as intended:
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
static unsigned char x[~0U];
static void handle(int) { }
int main(int argc, char *argv[])
{
pid_t pid = getpid(), child;
int fd;
signal(SIGUSR1, handle);
if (!(child = fork())) {
for (;;)
kill(pid, SIGUSR1);
}
fd = open("/dev/urandom", O_WRONLY);
pause();
printf("interrupted after writing %zd bytes\n", write(fd, x, sizeof(x)));
close(fd);
kill(child, SIGTERM);
return 0;
}
Result before: "interrupted after writing
2147479552 bytes"
Result after: "interrupted after writing 4096 bytes"
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jens Axboe [Thu, 19 May 2022 23:31:37 +0000 (17:31 -0600)]
random: wire up fops->splice_{read,write}_iter()
commit
79025e727a846be6fd215ae9cdb654368ac3f9a6 upstream.
Now that random/urandom is using {read,write}_iter, we can wire it up to
using the generic splice handlers.
Fixes:
36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[Jason: added the splice_write path. Note that sendfile() and such still
does not work for read, though it does for write, because of a file
type restriction in splice_direct_to_actor(), which I'll address
separately.]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jens Axboe [Thu, 19 May 2022 23:43:15 +0000 (17:43 -0600)]
random: convert to using fops->write_iter()
commit
22b0a222af4df8ee9bb8e07013ab44da9511b047 upstream.
Now that the read side has been converted to fix a regression with
splice, convert the write side as well to have some symmetry in the
interface used (and help deprecate ->write()).
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[Jason: cleaned up random_ioctl a bit, require full writes in
RNDADDENTROPY since it's crediting entropy, simplify control flow of
write_pool(), and incorporate suggestions from Al.]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jens Axboe [Thu, 19 May 2022 23:31:36 +0000 (17:31 -0600)]
random: convert to using fops->read_iter()
commit
1b388e7765f2eaa137cf5d92b47ef5925ad83ced upstream.
This is a pre-requisite to wiring up splice() again for the random
and urandom drivers. It also allows us to remove the INT_MAX check in
getrandom(), because import_single_range() applies capping internally.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[Jason: rewrote get_random_bytes_user() to simplify and also incorporate
additional suggestions from Al.]
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 14 May 2022 22:22:05 +0000 (00:22 +0200)]
random: unify batched entropy implementations
commit
3092adcef3ffd2ef59634998297ca8358461ebce upstream.
There are currently two separate batched entropy implementations, for
u32 and u64, with nearly identical code, with the goal of avoiding
unaligned memory accesses and letting the buffers be used more
efficiently. Having to maintain these two functions independently is a
bit of a hassle though, considering that they always need to be kept in
sync.
This commit factors them out into a type-generic macro, so that the
expansion produces the same code as before, such that diffing the
assembly shows no differences. This will also make it easier in the
future to add u16 and u8 batches.
This was initially tested using an always_inline function and letting
gcc constant fold the type size in, but the code gen was less efficient,
and in general it was more verbose and harder to follow. So this patch
goes with the boring macro solution, similar to what's already done for
the _wait functions in random.h.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 14 May 2022 11:59:30 +0000 (13:59 +0200)]
random: move randomize_page() into mm where it belongs
commit
5ad7dd882e45d7fe432c32e896e2aaa0b21746ea upstream.
randomize_page is an mm function. It is documented like one. It contains
the history of one. It has the naming convention of one. It looks
just like another very similar function in mm, randomize_stack_top().
And it has always been maintained and updated by mm people. There is no
need for it to be in random.c. In the "which shape does not look like
the other ones" test, pointing to randomize_page() is correct.
So move randomize_page() into mm/util.c, right next to the similar
randomize_stack_top() function.
This commit contains no actual code changes.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 13 May 2022 14:17:12 +0000 (16:17 +0200)]
random: move initialization functions out of hot pages
commit
560181c27b582557d633ecb608110075433383af upstream.
Much of random.c is devoted to initializing the rng and accounting for
when a sufficient amount of entropy has been added. In a perfect world,
this would all happen during init, and so we could mark these functions
as __init. But in reality, this isn't the case: sometimes the rng only
finishes initializing some seconds after system init is finished.
For this reason, at the moment, a whole host of functions that are only
used relatively close to system init and then never again are intermixed
with functions that are used in hot code all the time. This creates more
cache misses than necessary.
In order to pack the hot code closer together, this commit moves the
initialization functions that can't be marked as __init into
.text.unlikely by way of the __cold attribute.
Of particular note is moving credit_init_bits() into a macro wrapper
that inlines the crng_ready() static branch check. This avoids a
function call to a nop+ret, and most notably prevents extra entropy
arithmetic from being computed in mix_interrupt_randomness().
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 13 May 2022 11:18:46 +0000 (13:18 +0200)]
random: make consistent use of buf and len
commit
a19402634c435a4eae226df53c141cdbb9922e7b upstream.
The current code was a mix of "nbytes", "count", "size", "buffer", "in",
and so forth. Instead, let's clean this up by naming input parameters
"buf" (or "ubuf") and "len", so that you always understand that you're
reading this variety of function argument.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 13 May 2022 10:32:23 +0000 (12:32 +0200)]
random: use proper return types on get_random_{int,long}_wait()
commit
7c3a8a1db5e03d02cc0abb3357a84b8b326dfac3 upstream.
Before these were returning signed values, but the API is intended to be
used with unsigned values.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 13 May 2022 10:29:38 +0000 (12:29 +0200)]
random: remove extern from functions in header
commit
7782cfeca7d420e8bb707613d4cfb0f7ff29bb3a upstream.
Accoriding to the kernel style guide, having `extern` on functions in
headers is old school and deprecated, and doesn't add anything. So remove
them from random.h, and tidy up the file a little bit too.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 3 May 2022 13:30:45 +0000 (15:30 +0200)]
random: use static branch for crng_ready()
commit
f5bda35fba615ace70a656d4700423fa6c9bebee upstream.
Since crng_ready() is only false briefly during initialization and then
forever after becomes true, we don't need to evaluate it after, making
it a prime candidate for a static branch.
One complication, however, is that it changes state in a particular call
to credit_init_bits(), which might be made from atomic context, which
means we must kick off a workqueue to change the static key. Further
complicating things, credit_init_bits() may be called sufficiently early
on in system initialization such that system_wq is NULL.
Fortunately, there exists the nice function execute_in_process_context(),
which will immediately execute the function if !in_interrupt(), and
otherwise defer it to a workqueue. During early init, before workqueues
are available, in_interrupt() is always false, because interrupts
haven't even been enabled yet, which means the function in that case
executes immediately. Later on, after workqueues are available,
in_interrupt() might be true, but in that case, the work is queued in
system_wq and all goes well.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Sultan Alsawaf <sultan@kerneltoast.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Thu, 12 May 2022 13:32:26 +0000 (15:32 +0200)]
random: credit architectural init the exact amount
commit
12e45a2a6308105469968951e6d563e8f4fea187 upstream.
RDRAND and RDSEED can fail sometimes, which is fine. We currently
initialize the RNG with 512 bits of RDRAND/RDSEED. We only need 256 bits
of those to succeed in order to initialize the RNG. Instead of the
current "all or nothing" approach, actually credit these contributions
the amount that is actually contributed.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Thu, 5 May 2022 00:20:22 +0000 (02:20 +0200)]
random: handle latent entropy and command line from random_init()
commit
2f14062bb14b0fcfcc21e6dc7d5b5c0d25966164 upstream.
Currently, start_kernel() adds latent entropy and the command line to
the entropy bool *after* the RNG has been initialized, deferring when
it's actually used by things like stack canaries until the next time
the pool is seeded. This surely is not intended.
Rather than splitting up which entropy gets added where and when between
start_kernel() and random_init(), just do everything in random_init(),
which should eliminate these kinds of bugs in the future.
While we're at it, rename the awkwardly titled "rand_initialize()" to
the more standard "random_init()" nomenclature.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 10 May 2022 13:20:42 +0000 (15:20 +0200)]
random: use proper jiffies comparison macro
commit
8a5b8a4a4ceb353b4dd5bafd09e2b15751bcdb51 upstream.
This expands to exactly the same code that it replaces, but makes things
consistent by using the same macro for jiffy comparisons throughout.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Mon, 9 May 2022 14:13:18 +0000 (16:13 +0200)]
random: remove ratelimiting for in-kernel unseeded randomness
commit
cc1e127bfa95b5fb2f9307e7168bf8b2b45b4c5e upstream.
The CONFIG_WARN_ALL_UNSEEDED_RANDOM debug option controls whether the
kernel warns about all unseeded randomness or just the first instance.
There's some complicated rate limiting and comparison to the previous
caller, such that even with CONFIG_WARN_ALL_UNSEEDED_RANDOM enabled,
developers still don't see all the messages or even an accurate count of
how many were missed. This is the result of basically parallel
mechanisms aimed at accomplishing more or less the same thing, added at
different points in random.c history, which sort of compete with the
first-instance-only limiting we have now.
It turns out, however, that nobody cares about the first unseeded
randomness instance of in-kernel users. The same first user has been
there for ages now, and nobody is doing anything about it. It isn't even
clear that anybody _can_ do anything about it. Most places that can do
something about it have switched over to using get_random_bytes_wait()
or wait_for_random_bytes(), which is the right thing to do, but there is
still much code that needs randomness sometimes during init, and as a
geeneral rule, if you're not using one of the _wait functions or the
readiness notifier callback, you're bound to be doing it wrong just
based on that fact alone.
So warning about this same first user that can't easily change is simply
not an effective mechanism for anything at all. Users can't do anything
about it, as the Kconfig text points out -- the problem isn't in
userspace code -- and kernel developers don't or more often can't react
to it.
Instead, show the warning for all instances when CONFIG_WARN_ALL_UNSEEDED_RANDOM
is set, so that developers can debug things need be, or if it isn't set,
don't show a warning at all.
At the same time, CONFIG_WARN_ALL_UNSEEDED_RANDOM now implies setting
random.ratelimit_disable=1 on by default, since if you care about one
you probably care about the other too. And we can clean up usage around
the related urandom_warning ratelimiter as well (whose behavior isn't
changing), so that it properly counts missed messages after the 10
message threshold is reached.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Mon, 9 May 2022 11:53:24 +0000 (13:53 +0200)]
random: move initialization out of reseeding hot path
commit
68c9c8b192c6dae9be6278e98ee44029d5da2d31 upstream.
Initialization happens once -- by way of credit_init_bits() -- and then
it never happens again. Therefore, it doesn't need to be in
crng_reseed(), which is a hot path that is called multiple times. It
also doesn't make sense to have there, as initialization activity is
better associated with initialization routines.
After the prior commit, crng_reseed() now won't be called by multiple
concurrent callers, which means that we can safely move the
"finialize_init" logic into crng_init_bits() unconditionally.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Mon, 9 May 2022 11:40:55 +0000 (13:40 +0200)]
random: avoid initializing twice in credit race
commit
fed7ef061686cc813b1f3d8d0edc6c35b4d3537b upstream.
Since all changes of crng_init now go through credit_init_bits(), we can
fix a long standing race in which two concurrent callers of
credit_init_bits() have the new bit count >= some threshold, but are
doing so with crng_init as a lower threshold, checked outside of a lock,
resulting in crng_reseed() or similar being called twice.
In order to fix this, we can use the original cmpxchg value of the bit
count, and only change crng_init when the bit count transitions from
below a threshold to meeting the threshold.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sun, 8 May 2022 11:20:30 +0000 (13:20 +0200)]
random: use symbolic constants for crng_init states
commit
e3d2c5e79a999aa4e7d6f0127e16d3da5a4ff70d upstream.
crng_init represents a state machine, with three states, and various
rules for transitions. For the longest time, we've been managing these
with "0", "1", and "2", and expecting people to figure it out. To make
the code more obvious, replace these with proper enum values
representing the transition, and then redocument what each of these
states mean.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 7 May 2022 12:03:46 +0000 (14:03 +0200)]
siphash: use one source of truth for siphash permutations
commit
e73aaae2fa9024832e1f42e30c787c7baf61d014 upstream.
The SipHash family of permutations is currently used in three places:
- siphash.c itself, used in the ordinary way it was intended.
- random32.c, in a construction from an anonymous contributor.
- random.c, as part of its fast_mix function.
Each one of these places reinvents the wheel with the same C code, same
rotation constants, and same symmetry-breaking constants.
This commit tidies things up a bit by placing macros for the
permutations and constants into siphash.h, where each of the three .c
users can access them. It also leaves a note dissuading more users of
them from emerging.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 6 May 2022 21:19:43 +0000 (23:19 +0200)]
random: help compiler out with fast_mix() by using simpler arguments
commit
791332b3cbb080510954a4c152ce02af8832eac9 upstream.
Now that fast_mix() has more than one caller, gcc no longer inlines it.
That's fine. But it also doesn't handle the compound literal argument we
pass it very efficiently, nor does it handle the loop as well as it
could. So just expand the code to spell out this function so that it
generates the same code as it did before. Performance-wise, this now
behaves as it did before the last commit. The difference in actual code
size on x86 is 45 bytes, which is less than a cache line.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 6 May 2022 16:30:51 +0000 (18:30 +0200)]
random: do not use input pool from hard IRQs
commit
e3e33fc2ea7fcefd0d761db9d6219f83b4248f5c upstream.
Years ago, a separate fast pool was added for interrupts, so that the
cost associated with taking the input pool spinlocks and mixing into it
would be avoided in places where latency is critical. However, one
oversight was that add_input_randomness() and add_disk_randomness()
still sometimes are called directly from the interrupt handler, rather
than being deferred to a thread. This means that some unlucky interrupts
will be caught doing a blake2s_compress() call and potentially spinning
on input_pool.lock, which can also be taken by unprivileged users by
writing into /dev/urandom.
In order to fix this, add_timer_randomness() now checks whether it is
being called from a hard IRQ and if so, just mixes into the per-cpu IRQ
fast pool using fast_mix(), which is much faster and can be done
lock-free. A nice consequence of this, as well, is that it means hard
IRQ context FPU support is likely no longer useful.
The entropy estimation algorithm used by add_timer_randomness() is also
somewhat different than the one used for add_interrupt_randomness(). The
former looks at deltas of deltas of deltas, while the latter just waits
for 64 interrupts for one bit or for one second since the last bit. In
order to bridge these, and since add_interrupt_randomness() runs after
an add_timer_randomness() that's called from hard IRQ, we add to the
fast pool credit the related amount, and then subtract one to account
for add_interrupt_randomness()'s contribution.
A downside of this, however, is that the num argument is potentially
attacker controlled, which puts a bit more pressure on the fast_mix()
sponge to do more than it's really intended to do. As a mitigating
factor, the first 96 bits of input aren't attacker controlled (a cycle
counter followed by zeros), which means it's essentially two rounds of
siphash rather than one, which is somewhat better. It's also not that
much different from add_interrupt_randomness()'s use of the irq stack
instruction pointer register.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Filipe Manana <fdmanana@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 6 May 2022 16:27:38 +0000 (18:27 +0200)]
random: order timer entropy functions below interrupt functions
commit
a4b5c26b79ffdfcfb816c198f2fc2b1e7b5b580f upstream.
There are no code changes here; this is just a reordering of functions,
so that in subsequent commits, the timer entropy functions can call into
the interrupt ones.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 30 Apr 2022 20:03:29 +0000 (22:03 +0200)]
random: do not pretend to handle premature next security model
commit
e85c0fc1d94c52483a603651748d4c76d6aa1c6b upstream.
Per the thread linked below, "premature next" is not considered to be a
realistic threat model, and leads to more serious security problems.
"Premature next" is the scenario in which:
- Attacker compromises the current state of a fully initialized RNG via
some kind of infoleak.
- New bits of entropy are added directly to the key used to generate the
/dev/urandom stream, without any buffering or pooling.
- Attacker then, somehow having read access to /dev/urandom, samples RNG
output and brute forces the individual new bits that were added.
- Result: the RNG never "recovers" from the initial compromise, a
so-called violation of what academics term "post-compromise security".
The usual solutions to this involve some form of delaying when entropy
gets mixed into the crng. With Fortuna, this involves multiple input
buckets. With what the Linux RNG was trying to do prior, this involves
entropy estimation.
However, by delaying when entropy gets mixed in, it also means that RNG
compromises are extremely dangerous during the window of time before
the RNG has gathered enough entropy, during which time nonces may become
predictable (or repeated), ephemeral keys may not be secret, and so
forth. Moreover, it's unclear how realistic "premature next" is from an
attack perspective, if these attacks even make sense in practice.
Put together -- and discussed in more detail in the thread below --
these constitute grounds for just doing away with the current code that
pretends to handle premature next. I say "pretends" because it wasn't
doing an especially great job at it either; should we change our mind
about this direction, we would probably implement Fortuna to "fix" the
"problem", in which case, removing the pretend solution still makes
sense.
This also reduces the crng reseed period from 5 minutes down to 1
minute. The rationale from the thread might lead us toward reducing that
even further in the future (or even eliminating it), but that remains a
topic of a future commit.
At a high level, this patch changes semantics from:
Before: Seed for the first time after 256 "bits" of estimated
entropy have been accumulated since the system booted. Thereafter,
reseed once every five minutes, but only if 256 new "bits" have been
accumulated since the last reseeding.
After: Seed for the first time after 256 "bits" of estimated entropy
have been accumulated since the system booted. Thereafter, reseed
once every minute.
Most of this patch is renaming and removing: POOL_MIN_BITS becomes
POOL_INIT_BITS, credit_entropy_bits() becomes credit_init_bits(),
crng_reseed() loses its "force" parameter since it's now always true,
the drain_entropy() function no longer has any use so it's removed,
entropy estimation is skipped if we've already init'd, the various
notifiers for "low on entropy" are now only active prior to init, and
finally, some documentation comments are cleaned up here and there.
Link: https://lore.kernel.org/lkml/YmlMGx6+uigkGiZ0@zx2c4.com/
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Nadia Heninger <nadiah@cs.ucsd.edu>
Cc: Tom Ristenpart <ristenpart@cornell.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 30 Apr 2022 13:08:20 +0000 (15:08 +0200)]
random: use first 128 bits of input as fast init
commit
5c3b747ef54fa2a7318776777f6044540d99f721 upstream.
Before, the first 64 bytes of input, regardless of how entropic it was,
would be used to mutate the crng base key directly, and none of those
bytes would be credited as having entropy. Then 256 bits of credited
input would be accumulated, and only then would the rng transition from
the earlier "fast init" phase into being actually initialized.
The thinking was that by mixing and matching fast init and real init, an
attacker who compromised the fast init state, considered easy to do
given how little entropy might be in those first 64 bytes, would then be
able to bruteforce bits from the actual initialization. By keeping these
separate, bruteforcing became impossible.
However, by not crediting potentially creditable bits from those first 64
bytes of input, we delay initialization, and actually make the problem
worse, because it means the user is drawing worse random numbers for a
longer period of time.
Instead, we can take the first 128 bits as fast init, and allow them to
be credited, and then hold off on the next 128 bits until they've
accumulated. This is still a wide enough margin to prevent bruteforcing
the rng state, while still initializing much faster.
Then, rather than trying to piecemeal inject into the base crng key at
various points, instead just extract from the pool when we need it, for
the crng_init==0 phase. Performance may even be better for the various
inputs here, since there are likely more calls to mix_pool_bytes() then
there are to get_random_bytes() during this phase of system execution.
Since the preinit injection code is gone, bootloader randomness can then
do something significantly more straight forward, removing the weird
system_wq hack in hwgenerator randomness.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 3 May 2022 12:14:32 +0000 (14:14 +0200)]
random: do not use batches when !crng_ready()
commit
cbe89e5a375a51bbb952929b93fa973416fea74e upstream.
It's too hard to keep the batches synchronized, and pointless anyway,
since in !crng_ready(), we're updating the base_crng key really often,
where batching only hurts. So instead, if the crng isn't ready, just
call into get_random_bytes(). At this stage nothing is performance
critical anyhow.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 12 Apr 2022 17:59:57 +0000 (19:59 +0200)]
random: insist on random_get_entropy() existing in order to simplify
commit
4b758eda851eb9336ca86a0041a4d3da55f66511 upstream.
All platforms are now guaranteed to provide some value for
random_get_entropy(). In case some bug leads to this not being so, we
print a warning, because that indicates that something is really very
wrong (and likely other things are impacted too). This should never be
hit, but it's a good and cheap way of finding out if something ever is
problematic.
Since we now have viable fallback code for random_get_entropy() on all
platforms, which is, in the worst case, not worse than jiffies, we can
count on getting the best possible value out of it. That means there's
no longer a use for using jiffies as entropy input. It also means we no
longer have a reason for doing the round-robin register flow in the IRQ
handler, which was always of fairly dubious value.
Instead we can greatly simplify the IRQ handler inputs and also unify
the construction between 64-bits and 32-bits. We now collect the cycle
counter and the return address, since those are the two things that
matter. Because the return address and the irq number are likely
related, to the extent we mix in the irq number, we can just xor it into
the top unchanging bytes of the return address, rather than the bottom
changing bytes of the cycle counter as before. Then, we can do a fixed 2
rounds of SipHash/HSipHash. Finally, we use the same construction of
hashing only half of the [H]SipHash state on 32-bit and 64-bit. We're
not actually discarding any entropy, since that entropy is carried
through until the next time. And more importantly, it lets us do the
same sponge-like construction everywhere.
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
xtensa: use fallback for random_get_entropy() instead of zero
commit
e10e2f58030c5c211d49042a8c2a1b93d40b2ffb upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
sparc: use fallback for random_get_entropy() instead of zero
commit
ac9756c79797bb98972736b13cfb239fd2cffb79 upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
um: use fallback for random_get_entropy() instead of zero
commit
9f13fb0cd11ed2327abff69f6501a2c124c88b5a upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
This is accomplished by just including the asm-generic code like on
other architectures, which means we can get rid of the empty stub
function here.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
x86/tsc: Use fallback for random_get_entropy() instead of zero
commit
3bd4abc07a267e6a8b33d7f8717136e18f921c53 upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is suboptimal. Instead, fallback
to calling random_get_entropy_fallback(), which isn't extremely high
precision or guaranteed to be entropic, but is certainly better than
returning zero all the time.
If CONFIG_X86_TSC=n, then it's possible for the kernel to run on systems
without RDTSC, such as 486 and certain 586, so the fallback code is only
required for that case.
As well, fix up both the new function and the get_cycles() function from
which it was derived to use cpu_feature_enabled() rather than
boot_cpu_has(), and use !IS_ENABLED() instead of #ifndef.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
nios2: use fallback for random_get_entropy() instead of zero
commit
c04e72700f2293013dab40208e809369378f224c upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
arm: use fallback for random_get_entropy() instead of zero
commit
ff8a8f59c99f6a7c656387addc4d9f2247d75077 upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
mips: use fallback for random_get_entropy() instead of just c0 random
commit
1c99c6a7c3c599a68321b01b9ec243215ede5a68 upstream.
For situations in which we don't have a c0 counter register available,
we've been falling back to reading the c0 "random" register, which is
usually bounded by the amount of TLB entries and changes every other
cycle or so. This means it wraps extremely often. We can do better by
combining this fast-changing counter with a potentially slower-changing
counter from random_get_entropy_fallback() in the more significant bits.
This commit combines the two, taking into account that the changing bits
are in a different bit position depending on the CPU model. In addition,
we previously were falling back to 0 for ancient CPUs that Linux does
not support anyway; remove that dead path entirely.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Tested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
riscv: use fallback for random_get_entropy() instead of zero
commit
6d01238623faa9425f820353d2066baf6c9dc872 upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:03:13 +0000 (18:03 +0200)]
m68k: use fallback for random_get_entropy() instead of zero
commit
0f392c95391f2d708b12971a07edaa7973f9eece upstream.
In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sun, 10 Apr 2022 14:49:50 +0000 (16:49 +0200)]
timekeeping: Add raw clock fallback for random_get_entropy()
commit
1366992e16bddd5e2d9a561687f367f9f802e2e4 upstream.
The addition of random_get_entropy_fallback() provides access to
whichever time source has the highest frequency, which is useful for
gathering entropy on platforms without available cycle counters. It's
not necessarily as good as being able to quickly access a cycle counter
that the CPU has, but it's still something, even when it falls back to
being jiffies-based.
In the event that a given arch does not define get_cycles(), falling
back to the get_cycles() default implementation that returns 0 is really
not the best we can do. Instead, at least calling
random_get_entropy_fallback() would be preferable, because that always
needs to return _something_, even falling back to jiffies eventually.
It's not as though random_get_entropy_fallback() is super high precision
or guaranteed to be entropic, but basically anything that's not zero all
the time is better than returning zero all the time.
Finally, since random_get_entropy_fallback() is used during extremely
early boot when randomizing freelists in mm_init(), it can be called
before timekeeping has been initialized. In that case there really is
nothing we can do; jiffies hasn't even started ticking yet. So just give
up and return 0.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 23 Apr 2022 19:11:41 +0000 (21:11 +0200)]
powerpc: define get_cycles macro for arch-override
commit
408835832158df0357e18e96da7f2d1ed6b80e7f upstream.
PowerPC defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@ozlabs.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 23 Apr 2022 19:11:41 +0000 (21:11 +0200)]
alpha: define get_cycles macro for arch-override
commit
1097710bc9660e1e588cf2186a35db3d95c4d258 upstream.
Alpha defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 23 Apr 2022 19:11:41 +0000 (21:11 +0200)]
parisc: define get_cycles macro for arch-override
commit
8865bbe6ba1120e67f72201b7003a16202cd42be upstream.
PA-RISC defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 23 Apr 2022 19:11:41 +0000 (21:11 +0200)]
s390: define get_cycles macro for arch-override
commit
2e3df523256cb9836de8441e9c791a796759bb3c upstream.
S390x defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Sat, 23 Apr 2022 19:11:41 +0000 (21:11 +0200)]
ia64: define get_cycles macro for arch-override
commit
57c0900b91d8891ab43f0e6b464d059fda51d102 upstream.
Itanium defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Thu, 5 May 2022 00:20:22 +0000 (02:20 +0200)]
init: call time_init() before rand_initialize()
commit
fe222a6ca2d53c38433cba5d3be62a39099e708e upstream.
Currently time_init() is called after rand_initialize(), but
rand_initialize() makes use of the timer on various platforms, and
sometimes this timer needs to be initialized by time_init() first. In
order for random_get_entropy() to not return zero during early boot when
it's potentially used as an entropy source, reverse the order of these
two calls. The block doing random initialization was right before
time_init() before, so changing the order shouldn't have any complicated
effects.
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 3 May 2022 19:43:58 +0000 (21:43 +0200)]
random: fix sysctl documentation nits
commit
069c4ea6871c18bd368f27756e0f91ffb524a788 upstream.
A semicolon was missing, and the almost-alphabetical-but-not ordering
was confusing, so regroup these by category instead.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Mon, 18 Apr 2022 18:57:31 +0000 (20:57 +0200)]
random: document crng_fast_key_erasure() destination possibility
commit
8717627d6ac53251ee012c3c7aca392f29f38a42 upstream.
This reverts
35a33ff3807d ("random: use memmove instead of memcpy for
remaining 32 bytes"), which was made on a totally bogus basis. The thing
it was worried about overlapping came from the stack, not from one of
its arguments, as Eric pointed out.
But the fact that this confusion even happened draws attention to the
fact that it's a bit non-obvious that the random_data parameter can
alias chacha_state, and in fact should do so when the caller can't rely
on the stack being cleared in a timely manner. So this commit documents
that.
Reported-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Fri, 8 Apr 2022 16:14:57 +0000 (18:14 +0200)]
random: make random_get_entropy() return an unsigned long
commit
b0c3e796f24b588b862b61ce235d3c9417dc8983 upstream.
Some implementations were returning type `unsigned long`, while others
that fell back to get_cycles() were implicitly returning a `cycles_t` or
an untyped constant int literal. That makes for weird and confusing
code, and basically all code in the kernel already handled it like it
was an `unsigned long`. I recently tried to handle it as the largest
type it could be, a `cycles_t`, but doing so doesn't really help with
much.
Instead let's just make random_get_entropy() return an unsigned long all
the time. This also matches the commonly used `arch_get_random_long()`
function, so now RDRAND and RDTSC return the same sized integer, which
means one can fallback to the other more gracefully.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Thu, 7 Apr 2022 19:23:08 +0000 (21:23 +0200)]
random: allow partial reads if later user copies fail
commit
5209aed5137880fa229746cb521f715e55596460 upstream.
Rather than failing entirely if a copy_to_user() fails at some point,
instead we should return a partial read for the amount that succeeded
prior, unless none succeeded at all, in which case we return -EFAULT as
before.
This makes it consistent with other reader interfaces. For example, the
following snippet for /dev/zero outputs "4" followed by "1":
int fd;
void *x = mmap(NULL, 4096, PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
assert(x != MAP_FAILED);
fd = open("/dev/zero", O_RDONLY);
assert(fd >= 0);
printf("%zd\n", read(fd, x, 4));
printf("%zd\n", read(fd, x + 4095, 4));
close(fd);
This brings that same standard behavior to the various RNG reader
interfaces.
While we're at it, we can streamline the loop logic a little bit.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Wed, 6 Apr 2022 00:36:16 +0000 (02:36 +0200)]
random: check for signals every PAGE_SIZE chunk of /dev/[u]random
commit
e3c1c4fd9e6d14059ed93ebfe15e1c57793b1a05 upstream.
In
1448769c9cdb ("random: check for signal_pending() outside of
need_resched() check"), Jann pointed out that we previously were only
checking the TIF_NOTIFY_SIGNAL and TIF_SIGPENDING flags if the process
had TIF_NEED_RESCHED set, which meant in practice, super long reads to
/dev/[u]random would delay signal handling by a long time. I tried this
using the below program, and indeed I wasn't able to interrupt a
/dev/urandom read until after several megabytes had been read. The bug
he fixed has always been there, and so code that reads from /dev/urandom
without checking the return value of read() has mostly worked for a long
time, for most sizes, not just for <= 256.
Maybe it makes sense to keep that code working. The reason it was so
small prior, ignoring the fact that it didn't work anyway, was likely
because /dev/random used to block, and that could happen for pretty
large lengths of time while entropy was gathered. But now, it's just a
chacha20 call, which is extremely fast and is just operating on pure
data, without having to wait for some external event. In that sense,
/dev/[u]random is a lot more like /dev/zero.
Taking a page out of /dev/zero's read_zero() function, it always returns
at least one chunk, and then checks for signals after each chunk. Chunk
sizes there are of length PAGE_SIZE. Let's just copy the same thing for
/dev/[u]random, and check for signals and cond_resched() for every
PAGE_SIZE amount of data. This makes the behavior more consistent with
expectations, and should mitigate the impact of Jann's fix for the
age-old signal check bug.
---- test program ----
#include <unistd.h>
#include <signal.h>
#include <stdio.h>
#include <sys/random.h>
static unsigned char x[~0U];
static void handle(int) { }
int main(int argc, char *argv[])
{
pid_t pid = getpid(), child;
signal(SIGUSR1, handle);
if (!(child = fork())) {
for (;;)
kill(pid, SIGUSR1);
}
pause();
printf("interrupted after reading %zd bytes\n", getrandom(x, sizeof(x), 0));
kill(child, SIGTERM);
return 0;
}
Cc: Jann Horn <jannh@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jann Horn [Tue, 5 Apr 2022 16:39:31 +0000 (18:39 +0200)]
random: check for signal_pending() outside of need_resched() check
commit
1448769c9cdb69ad65287f4f7ab58bc5f2f5d7ba upstream.
signal_pending() checks TIF_NOTIFY_SIGNAL and TIF_SIGPENDING, which
signal that the task should bail out of the syscall when possible. This
is a separate concept from need_resched(), which checks
TIF_NEED_RESCHED, signaling that the task should preempt.
In particular, with the current code, the signal_pending() bailout
probably won't work reliably.
Change this to look like other functions that read lots of data, such as
read_zero().
Fixes:
1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 5 Apr 2022 14:40:51 +0000 (16:40 +0200)]
random: do not allow user to keep crng key around on stack
commit
aba120cc101788544aa3e2c30c8da88513892350 upstream.
The fast key erasure RNG design relies on the key that's used to be used
and then discarded. We do this, making judicious use of
memzero_explicit(). However, reads to /dev/urandom and calls to
getrandom() involve a copy_to_user(), and userspace can use FUSE or
userfaultfd, or make a massive call, dynamically remap memory addresses
as it goes, and set the process priority to idle, in order to keep a
kernel stack alive indefinitely. By probing
/proc/sys/kernel/random/entropy_avail to learn when the crng key is
refreshed, a malicious userspace could mount this attack every 5 minutes
thereafter, breaking the crng's forward secrecy.
In order to fix this, we just overwrite the stack's key with the first
32 bytes of the "free" fast key erasure output. If we're returning <= 32
bytes to the user, then we can still return those bytes directly, so
that short reads don't become slower. And for long reads, the difference
is hopefully lost in the amortization, so it doesn't change much, with
that amortization helping variously for medium reads.
We don't need to do this for get_random_bytes() and the various
kernel-space callers, and later, if we ever switch to always batching,
this won't be necessary either, so there's no need to change the API of
these functions.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jann Horn <jannh@google.com>
Fixes:
c92e040d575a ("random: add backtracking protection to the CRNG")
Fixes:
186873c549df ("random: use simpler fast key erasure flow on per-cpu keys")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jan Varho [Mon, 4 Apr 2022 16:42:30 +0000 (19:42 +0300)]
random: do not split fast init input in add_hwgenerator_randomness()
commit
527a9867af29ff89f278d037db704e0ed50fb666 upstream.
add_hwgenerator_randomness() tries to only use the required amount of input
for fast init, but credits all the entropy, rather than a fraction of
it. Since it's hard to determine how much entropy is left over out of a
non-unformly random sample, either give it all to fast init or credit
it, but don't attempt to do both. In the process, we can clean up the
injection code to no longer need to return a value.
Signed-off-by: Jan Varho <jan.varho@gmail.com>
[Jason: expanded commit message]
Fixes:
73c7733f122e ("random: do not throw away excess input to crng_fast_load")
Cc: stable@vger.kernel.org # 5.17+, requires af704c856e88
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Thu, 31 Mar 2022 15:01:01 +0000 (11:01 -0400)]
random: mix build-time latent entropy into pool at init
commit
1754abb3e7583c570666fa1e1ee5b317e88c89a0 upstream.
Prior, the "input_pool_data" array needed no real initialization, and so
it was easy to mark it with __latent_entropy to populate it during
compile-time. In switching to using a hash function, this required us to
specifically initialize it to some specific state, which means we
dropped the __latent_entropy attribute. An unfortunate side effect was
this meant the pool was no longer seeded using compile-time random data.
In order to bring this back, we declare an array in rand_initialize()
with __latent_entropy and call mix_pool_bytes() on that at init, which
accomplishes the same thing as before. We make this __initconst, so that
it doesn't take up space at runtime after init.
Fixes:
6e8ec2552c7d ("random: use computational hash for entropy extraction")
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Wed, 23 Mar 2022 04:21:52 +0000 (22:21 -0600)]
random: re-add removed comment about get_random_{u32,u64} reseeding
commit
dd7aa36e535797926d8eb311da7151919130139d upstream.
The comment about get_random_{u32,u64}() not invoking reseeding got
added in an unrelated commit, that then was recently reverted by
0313bc278dac ("Revert "random: block in /dev/urandom""). So this adds
that little comment snippet back, and improves the wording a bit too.
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Wed, 23 Mar 2022 03:43:12 +0000 (21:43 -0600)]
random: treat bootloader trust toggle the same way as cpu trust toggle
commit
d97c68d178fbf8aaaf21b69b446f2dfb13909316 upstream.
If CONFIG_RANDOM_TRUST_CPU is set, the RNG initializes using RDRAND.
But, the user can disable (or enable) this behavior by setting
`random.trust_cpu=0/1` on the kernel command line. This allows system
builders to do reasonable things while avoiding howls from tinfoil
hatters. (Or vice versa.)
CONFIG_RANDOM_TRUST_BOOTLOADER is basically the same thing, but regards
the seed passed via EFI or device tree, which might come from RDRAND or
a TPM or somewhere else. In order to allow distros to more easily enable
this while avoiding those same howls (or vice versa), this commit adds
the corresponding `random.trust_bootloader=0/1` toggle.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Graham Christensen <graham@grahamc.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://github.com/NixOS/nixpkgs/pull/165355
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 22 Mar 2022 00:48:05 +0000 (18:48 -0600)]
random: skip fast_init if hwrng provides large chunk of entropy
commit
af704c856e888fb044b058d731d61b46eeec499d upstream.
At boot time, EFI calls add_bootloader_randomness(), which in turn calls
add_hwgenerator_randomness(). Currently add_hwgenerator_randomness()
feeds the first 64 bytes of randomness to the "fast init"
non-crypto-grade phase. But if add_hwgenerator_randomness() gets called
with more than POOL_MIN_BITS of entropy, there's no point in passing it
off to the "fast init" stage, since that's enough entropy to bootstrap
the real RNG. The "fast init" stage is just there to provide _something_
in the case where we don't have enough entropy to properly bootstrap the
RNG. But if we do have enough entropy to bootstrap the RNG, the current
logic doesn't serve a purpose. So, in the case where we're passed
greater than or equal to POOL_MIN_BITS of entropy, this commit makes us
skip the "fast init" phase.
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 8 Mar 2022 17:12:16 +0000 (10:12 -0700)]
random: check for signal and try earlier when generating entropy
commit
3e504d2026eb6c8762cd6040ae57db166516824a upstream.
Rather than waiting a full second in an interruptable waiter before
trying to generate entropy, try to generate entropy first and wait
second. While waiting one second might give an extra second for getting
entropy from elsewhere, we're already pretty late in the init process
here, and whatever else is generating entropy will still continue to
contribute. This has implications on signal handling: we call
try_to_generate_entropy() from wait_for_random_bytes(), and
wait_for_random_bytes() always uses wait_event_interruptible_timeout()
when waiting, since it's called by userspace code in restartable
contexts, where signals can pend. Since try_to_generate_entropy() now
runs first, if a signal is pending, it's necessary for
try_to_generate_entropy() to check for signals, since it won't hit the
wait until after try_to_generate_entropy() has returned. And even before
this change, when entering a busy loop in try_to_generate_entropy(), we
should have been checking to see if any signals are pending, so that a
process doesn't get stuck in that loop longer than expected.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Wed, 9 Mar 2022 06:32:34 +0000 (23:32 -0700)]
random: reseed more often immediately after booting
commit
7a7ff644aeaf071d433caffb3b8ea57354b55bd3 upstream.
In order to chip away at the "premature first" problem, we augment our
existing entropy accounting with more frequent reseedings at boot.
The idea is that at boot, we're getting entropy from various places, and
we're not very sure which of early boot entropy is good and which isn't.
Even when we're crediting the entropy, we're still not totally certain
that it's any good. Since boot is the one time (aside from a compromise)
that we have zero entropy, it's important that we shepherd entropy into
the crng fairly often.
At the same time, we don't want a "premature next" problem, whereby an
attacker can brute force individual bits of added entropy. In lieu of
going full-on Fortuna (for now), we can pick a simpler strategy of just
reseeding more often during the first 5 minutes after boot. This is
still bounded by the 256-bit entropy credit requirement, so we'll skip a
reseeding if we haven't reached that, but in case entropy /is/ coming
in, this ensures that it makes its way into the crng rather rapidly
during these early stages.
Ordinarily we reseed if the previous reseeding is 300 seconds old. This
commit changes things so that for the first 600 seconds of boot time, we
reseed if the previous reseeding is uptime / 2 seconds old. That means
that we'll reseed at the very least double the uptime of the previous
reseeding.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jason A. Donenfeld [Tue, 8 Mar 2022 18:20:17 +0000 (11:20 -0700)]
random: make consistent usage of crng_ready()
commit
a96cfe2d427064325ecbf56df8816c6b871ec285 upstream.
Rather than sometimes checking `crng_init < 2`, we should always use the
crng_ready() macro, so that should we change anything later, it's
consistent. Additionally, that macro already has a likely() around it,
which means we don't need to open code our own likely() and unlikely()
annotations.
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
projects / platform / kernel / linux-rpi.git / log