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authorOleg Drokin <green@linuxhacker.ru>2016-06-17 16:48:23 -0400
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2016-06-24 12:01:00 -0400
commitcea7f829d3ea6e87a67220bc417260b858e278ff (patch)
tree341e7622acfab722984ca98526c4e508dd1fb3b1 /fs/nfs/nfs4state.c
parentd2a7de0b34cd255f23d4b7a7f065677f4b1c15f2 (diff)
downloadlinux-cea7f829d3ea6e87a67220bc417260b858e278ff.tar.bz2
nfs4: Fix potential use after free of state in nfs4_do_reclaim.
Commit e8d975e73e5f ("fixing infinite OPEN loop in 4.0 stateid recovery") introduced access to state after it was just potentially freed by nfs4_put_open_state leading to a random data corruption somewhere. BUG: unable to handle kernel paging request at ffff88004941ee40 IP: [<ffffffff813baf01>] nfs4_do_reclaim+0x461/0x740 PGD 3501067 PUD 3504067 PMD 6ff37067 PTE 800000004941e060 Oops: 0002 [#1] SMP DEBUG_PAGEALLOC Modules linked in: loop rpcsec_gss_krb5 acpi_cpufreq tpm_tis joydev i2c_piix4 pcspkr tpm virtio_console nfsd ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops floppy serio_raw virtio_blk drm CPU: 6 PID: 2161 Comm: 192.168.10.253- Not tainted 4.7.0-rc1-vm-nfs+ #112 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 task: ffff8800463dcd00 ti: ffff88003ff48000 task.ti: ffff88003ff48000 RIP: 0010:[<ffffffff813baf01>] [<ffffffff813baf01>] nfs4_do_reclaim+0x461/0x740 RSP: 0018:ffff88003ff4bd68 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffff81a49900 RCX: 00000000000000e8 RDX: 00000000000000e8 RSI: ffff8800418b9930 RDI: ffff880040c96c88 RBP: ffff88003ff4bdf8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff880040c96c98 R13: ffff88004941ee20 R14: ffff88004941ee40 R15: ffff88004941ee00 FS: 0000000000000000(0000) GS:ffff88006d000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88004941ee40 CR3: 0000000060b0b000 CR4: 00000000000006e0 Stack: ffffffff813baad5 ffff8800463dcd00 ffff880000000001 ffffffff810e6b68 ffff880043ddbc88 ffff8800418b9800 ffff8800418b98c8 ffff88004941ee48 ffff880040c96c90 ffff880040c96c00 ffff880040c96c20 ffff880040c96c40 Call Trace: [<ffffffff813baad5>] ? nfs4_do_reclaim+0x35/0x740 [<ffffffff810e6b68>] ? trace_hardirqs_on_caller+0x128/0x1b0 [<ffffffff813bb7cd>] nfs4_run_state_manager+0x5ed/0xa40 [<ffffffff813bb1e0>] ? nfs4_do_reclaim+0x740/0x740 [<ffffffff813bb1e0>] ? nfs4_do_reclaim+0x740/0x740 [<ffffffff810af0d1>] kthread+0x101/0x120 [<ffffffff810e6b68>] ? trace_hardirqs_on_caller+0x128/0x1b0 [<ffffffff818843af>] ret_from_fork+0x1f/0x40 [<ffffffff810aefd0>] ? kthread_create_on_node+0x250/0x250 Code: 65 80 4c 8b b5 78 ff ff ff e8 fc 88 4c 00 48 8b 7d 88 e8 13 67 d2 ff 49 8b 47 40 a8 02 0f 84 d3 01 00 00 4c 89 ff e8 7f f9 ff ff <f0> 41 80 26 7f 48 8b 7d c8 e8 b1 84 4c 00 e9 39 fd ff ff 3d e6 RIP [<ffffffff813baf01>] nfs4_do_reclaim+0x461/0x740 RSP <ffff88003ff4bd68> CR2: ffff88004941ee40 Signed-off-by: Oleg Drokin <green@linuxhacker.ru> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs/nfs4state.c')
-rw-r--r--fs/nfs/nfs4state.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 9679f4749364..834b875900d6 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1488,9 +1488,9 @@ restart:
}
spin_unlock(&state->state_lock);
}
- nfs4_put_open_state(state);
clear_bit(NFS_STATE_RECLAIM_NOGRACE,
&state->flags);
+ nfs4_put_open_state(state);
spin_lock(&sp->so_lock);
goto restart;
}