• Trond Myklebust's avatar
    NFS: Fix an uninitialised pointer Oops in the writeback error path · 3caa0c6e
    Trond Myklebust authored
    SteveD reports the following Oops:
     RIP: 0010:[<ffffffffa053461d>]  [<ffffffffa053461d>] __put_nfs_open_context+0x1d/0x100 [nfs]
     RSP: 0018:ffff880fed687b90  EFLAGS: 00010286
     RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000006
     RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
     RBP: ffff880fed687bc0 R08: 0000000000000092 R09: 000000000000047a
     R10: 0000000000000000 R11: ffff880fed6878d6 R12: ffff880fed687d20
     R13: ffff880fed687d20 R14: 0000000000000070 R15: ffffea000aa33ec0
     FS:  00007fce290f0740(0000) GS:ffff8807ffc60000(0000) knlGS:0000000000000000
     CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
     CR2: 0000000000000070 CR3: 00000007f2e79000 CR4: 00000000000007e0
     DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
     DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
     Stack:
      0000000000000000 ffff880036c5e510 ffff880fed687d20 ffff880fed687d20
      ffff880036c5e200 ffffea000aa33ec0 ffff880fed687bd0 ffffffffa0534710
      ffff880fed687be8 ffffffffa053d5f0 ffff880036c5e200 ffff880fed687c08
     Call Trace:
      [<ffffffffa0534710>] put_nfs_open_context+0x10/0x20 [nfs]
      [<ffffffffa053d5f0>] nfs_pgio_data_destroy+0x20/0x40 [nfs]
      [<ffffffffa053d672>] nfs_pgio_error+0x22/0x40 [nfs]
      [<ffffffffa053d8f4>] nfs_generic_pgio+0x74/0x2e0 [nfs]
      [<ffffffffa06b18c3>] pnfs_generic_pg_writepages+0x63/0x210 [nfsv4]
      [<ffffffffa053d579>] nfs_pageio_doio+0x19/0x50 [nfs]
      [<ffffffffa053eb84>] nfs_pageio_complete+0x24/0x30 [nfs]
      [<ffffffffa053cb25>] nfs_direct_write_schedule_iovec+0x115/0x1f0 [nfs]
      [<ffffffffa053675f>] ? nfs_get_lock_context+0x4f/0x120 [nfs]
      [<ffffffffa053d252>] nfs_file_direct_write+0x262/0x420 [nfs]
      [<ffffffffa0532d91>] nfs_file_write+0x131/0x1d0 [nfs]
      [<ffffffffa0532c60>] ? nfs_need_sync_write.isra.17+0x40/0x40 [nfs]
      [<ffffffff812127b8>] do_io_submit+0x3b8/0x840
      [<ffffffff81212c50>] SyS_io_submit+0x10/0x20
      [<ffffffff81610f29>] system_call_fastpath+0x16/0x1b
    
    This is due to the calls to nfs_pgio_error() in nfs_generic_pgio(), which
    happen before the nfs_pgio_header's open context is referenced in
    nfs_pgio_rpcsetup().
    Reported-by: default avatarSteve Dickson <SteveD@redhat.com>
    Cc: stable@vger.kernel.org # 3.16.x
    Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
    3caa0c6e
pagelist.c 28.2 KB