nfsd: Fix general protection fault in release_lock_stateid()
commit
f46c445b79906a9da55c13e0a6f6b6a006b892fe upstream.
When I push NFSv4.1 / RDMA hard, (xfstests generic/089, for example),
I get this crash on the server:
Oct 28 22:04:30 klimt kernel: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
Oct 28 22:04:30 klimt kernel: Modules linked in: cts rpcsec_gss_krb5 iTCO_wdt iTCO_vendor_support sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm btrfs irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd xor pcspkr raid6_pq i2c_i801 i2c_smbus lpc_ich mfd_core sg mei_me mei ioatdma shpchp wmi ipmi_si ipmi_msghandler rpcrdma ib_ipoib rdma_ucm acpi_power_meter acpi_pad ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c mlx4_ib mlx4_en ib_core sr_mod cdrom sd_mod ast drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel igb ahci libahci ptp mlx4_core pps_core dca libata i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod
Oct 28 22:04:30 klimt kernel: CPU: 7 PID: 1558 Comm: nfsd Not tainted 4.9.0-rc2-00005-g82cd754 #8
Oct 28 22:04:30 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Oct 28 22:04:30 klimt kernel: task:
ffff880835c3a100 task.stack:
ffff8808420d8000
Oct 28 22:04:30 klimt kernel: RIP: 0010:[<
ffffffffa05a759f>] [<
ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP: 0018:
ffff8808420dbce0 EFLAGS:
00010246
Oct 28 22:04:30 klimt kernel: RAX:
ffff88084e6660f0 RBX:
ffff88084e667020 RCX:
0000000000000000
Oct 28 22:04:30 klimt kernel: RDX:
0000000000000007 RSI:
0000000000000000 RDI:
ffff88084e667020
Oct 28 22:04:30 klimt kernel: RBP:
ffff8808420dbcf8 R08:
0000000000000001 R09:
0000000000000000
Oct 28 22:04:30 klimt kernel: R10:
ffff880835c3a100 R11:
ffff880835c3aca8 R12:
6b6b6b6b6b6b6b6b
Oct 28 22:04:30 klimt kernel: R13:
ffff88084e6670d8 R14:
ffff880835f546f0 R15:
ffff880835f1c548
Oct 28 22:04:30 klimt kernel: FS:
0000000000000000(0000) GS:
ffff88087bdc0000(0000) knlGS:
0000000000000000
Oct 28 22:04:30 klimt kernel: CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
Oct 28 22:04:30 klimt kernel: CR2:
00007ff020389000 CR3:
0000000001c06000 CR4:
00000000001406e0
Oct 28 22:04:30 klimt kernel: Stack:
Oct 28 22:04:30 klimt kernel:
ffff88084e667020 0000000000000000 ffff88084e6670d8 ffff8808420dbd20
Oct 28 22:04:30 klimt kernel:
ffffffffa05ac80d ffff880835f54548 ffff88084e640008 ffff880835f545b0
Oct 28 22:04:30 klimt kernel:
ffff8808420dbd70 ffffffffa059803d ffff880835f1c768 0000000000000870
Oct 28 22:04:30 klimt kernel: Call Trace:
Oct 28 22:04:30 klimt kernel: [<
ffffffffa05ac80d>] nfsd4_free_stateid+0xfd/0x1b0 [nfsd]
Oct 28 22:04:30 klimt kernel: [<
ffffffffa059803d>] nfsd4_proc_compound+0x40d/0x690 [nfsd]
Oct 28 22:04:30 klimt kernel: [<
ffffffffa0583114>] nfsd_dispatch+0xd4/0x1d0 [nfsd]
Oct 28 22:04:30 klimt kernel: [<
ffffffffa047bbf9>] svc_process_common+0x3d9/0x700 [sunrpc]
Oct 28 22:04:30 klimt kernel: [<
ffffffffa047ca64>] svc_process+0xf4/0x330 [sunrpc]
Oct 28 22:04:30 klimt kernel: [<
ffffffffa05827ca>] nfsd+0xfa/0x160 [nfsd]
Oct 28 22:04:30 klimt kernel: [<
ffffffffa05826d0>] ? nfsd_destroy+0x170/0x170 [nfsd]
Oct 28 22:04:30 klimt kernel: [<
ffffffff810b367b>] kthread+0x10b/0x120
Oct 28 22:04:30 klimt kernel: [<
ffffffff810b3570>] ? kthread_stop+0x280/0x280
Oct 28 22:04:30 klimt kernel: [<
ffffffff8174e8ba>] ret_from_fork+0x2a/0x40
Oct 28 22:04:30 klimt kernel: Code: c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 48 8b 87 b0 00 00 00 48 89 fb 4c 8b a0 98 00 00 00 <49> 8b 44 24 20 48 8d b8 80 03 00 00 e8 10 66 1a e1 48 89 df e8
Oct 28 22:04:30 klimt kernel: RIP [<
ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP <
ffff8808420dbce0>
Oct 28 22:04:30 klimt kernel: ---[ end trace
cf5d0b371973e167 ]---
Jeff Layton says:
> Hm...now that I look though, this is a little suspicious:
>
> struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner);
>
> I wonder if it's possible for the openstateid to have already been
> destroyed at this point.
>
> We might be better off doing something like this to get the client pointer:
>
> stp->st_stid.sc_client;
>
> ...which should be more direct and less dependent on other stateids
> staying valid.
With the suggested change, I am no longer able to reproduce the above oops.
v2: Fix unhash_lock_stateid() as well
Fix-suggested-by: Jeff Layton <jlayton@redhat.com>
Fixes:
42691398be08 ('nfsd: Fix race between FREE_STATEID and LOCK')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: Christian Theune <ct@flyingcircus.io>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>