fs: dlm: don't call kernel_getpeername() in error_report()
authorAlexander Aring <aahringo@redhat.com>
Mon, 15 Nov 2021 13:57:05 +0000 (08:57 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jan 2022 10:03:11 +0000 (11:03 +0100)
commitdba0aea5727ce2ba21a2388be3f86523c112d9df
tree912a360fa85e99daf84cf3c2ee6e70244fceb0b6
parentba43bd2be16b4d93281d51ce6ddf8746147ff7d8
fs: dlm: don't call kernel_getpeername() in error_report()

[ Upstream commit 4c3d90570bcc2b338f70f61f01110268e281ca3c ]

In some cases kernel_getpeername() will held the socket lock which is
already held when the socket layer calls error_report() callback. Since
commit 9dfc685e0262 ("inet: remove races in inet{6}_getname()") this
problem becomes more likely because the socket lock will be held always.
You will see something like:

bob9-u5 login: [  562.316860] BUG: spinlock recursion on CPU#7, swapper/7/0
[  562.318562]  lock: 0xffff8f2284720088, .magic: dead4ead, .owner: swapper/7/0, .owner_cpu: 7
[  562.319522] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 5.15.0+ #135
[  562.320346] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.13.0-2.module+el8.3.0+7353+9de0a3cc 04/01/2014
[  562.321277] Call Trace:
[  562.321529]  <IRQ>
[  562.321734]  dump_stack_lvl+0x33/0x42
[  562.322282]  do_raw_spin_lock+0x8b/0xc0
[  562.322674]  lock_sock_nested+0x1e/0x50
[  562.323057]  inet_getname+0x39/0x110
[  562.323425]  ? sock_def_readable+0x80/0x80
[  562.323838]  lowcomms_error_report+0x63/0x260 [dlm]
[  562.324338]  ? wait_for_completion_interruptible_timeout+0xd2/0x120
[  562.324949]  ? lock_timer_base+0x67/0x80
[  562.325330]  ? do_raw_spin_unlock+0x49/0xc0
[  562.325735]  ? _raw_spin_unlock_irqrestore+0x1e/0x40
[  562.326218]  ? del_timer+0x54/0x80
[  562.326549]  sk_error_report+0x12/0x70
[  562.326919]  tcp_validate_incoming+0x3c8/0x530
[  562.327347]  ? kvm_clock_read+0x14/0x30
[  562.327718]  ? ktime_get+0x3b/0xa0
[  562.328055]  tcp_rcv_established+0x121/0x660
[  562.328466]  tcp_v4_do_rcv+0x132/0x260
[  562.328835]  tcp_v4_rcv+0xcea/0xe20
[  562.329173]  ip_protocol_deliver_rcu+0x35/0x1f0
[  562.329615]  ip_local_deliver_finish+0x54/0x60
[  562.330050]  ip_local_deliver+0xf7/0x110
[  562.330431]  ? inet_rtm_getroute+0x211/0x840
[  562.330848]  ? ip_protocol_deliver_rcu+0x1f0/0x1f0
[  562.331310]  ip_rcv+0xe1/0xf0
[  562.331603]  ? ip_local_deliver+0x110/0x110
[  562.332011]  __netif_receive_skb_core+0x46a/0x1040
[  562.332476]  ? inet_gro_receive+0x263/0x2e0
[  562.332885]  __netif_receive_skb_list_core+0x13b/0x2c0
[  562.333383]  netif_receive_skb_list_internal+0x1c8/0x2f0
[  562.333896]  ? update_load_avg+0x7e/0x5e0
[  562.334285]  gro_normal_list.part.149+0x19/0x40
[  562.334722]  napi_complete_done+0x67/0x160
[  562.335134]  virtnet_poll+0x2ad/0x408 [virtio_net]
[  562.335644]  __napi_poll+0x28/0x140
[  562.336012]  net_rx_action+0x23d/0x300
[  562.336414]  __do_softirq+0xf2/0x2ea
[  562.336803]  irq_exit_rcu+0xc1/0xf0
[  562.337173]  common_interrupt+0xb9/0xd0

It is and was always forbidden to call kernel_getpeername() in context
of error_report(). To get rid of the problem we access the destination
address for the peer over the socket structure. While on it we fix to
print out the destination port of the inet socket.

Fixes: 1a31833d085a ("DLM: Replace nodeid_to_addr with kernel_getpeername")
Reported-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
fs/dlm/lowcomms.c