Commits
Trond Myklebust committed 3caa0c6ed75
NFS: Fix an uninitialised pointer Oops in the writeback error path 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: Steve Dickson <SteveD@redhat.com> Cc: stable@vger.kernel.org # 3.16.x Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>