[Ocfs2-devel] NULL pointer dereference at ocfs2_dir_foreach_blk_id
David Weber
wb at munzinger.de
Mon Jul 29 05:15:43 PDT 2013
Am Montag, 29. Juli 2013, 18:50:10 schrieb Jeff Liu:
> Hi David,
>
> Thanks for your report, could you try the fix below?
Yeah, that fixed the problem! Tested on top of 3.11.0-rc3
Thank you!
Cheers,
David
>
> From: Jie Liu <jeff.liu at oracle.com>
>
> This patch fix an NULL pointer deference while removing an empty
> directory, which was introduced by commits:
> commit: 3704412bdbf37ec836152f571ac74fe72220c05a
> [readdir] convert ocfs2
>
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: [< (null)>] (null)
> PGD 6da85067 PUD 6da89067 PMD 0
> Oops: 0010 [#1] SMP
> CPU: 0 PID: 6564 Comm: rmdir Tainted: G O 3.11.0-rc1 #4
> RIP: 0010:[<0000000000000000>] [< (null)>] (null)
> Call Trace:
> [<ffffffffa038a30e>] ? ocfs2_dir_foreach_blk_id+0x17e/0x220 [ocfs2]
> [<ffffffffa038e5f9>] ocfs2_dir_foreach+0x49/0x50 [ocfs2]
> [<ffffffffa038ec2c>] ocfs2_empty_dir+0x12c/0x3e0 [ocfs2]
> [<ffffffffa03b3ade>] ocfs2_unlink+0x56e/0xc10 [ocfs2]
> [<ffffffff811b3a05>] vfs_rmdir+0xd5/0x140
> [<ffffffff811b3c3b>] do_rmdir+0x1cb/0x1e0
> [<ffffffff813697f4>] ? lockdep_sys_exit_thunk+0x35/0x67
> [<ffffffff8136977e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
> [<ffffffff811b6996>] SyS_rmdir+0x16/0x20
> [<ffffffff816e2a82>] system_call_fastpath+0x16/0x1b
> Code: Bad RIP value.
> RIP [< (null)>] (null)
> RSP <ffff88006daddc10>
> CR2: 0000000000000000
> ---[ end trace dbb276999e4cdc71 ]---
>
> Reported-by: David Weber <wb at munzinger.de>
> Cc: Al Viro <viro at zeniv.linux.org.uk>
> Signed-off-by: Jie Liu <jeff.liu at oracle.com>
> ---
> fs/ocfs2/dir.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
> index eb760d8..c91d986 100644
> --- a/fs/ocfs2/dir.c
> +++ b/fs/ocfs2/dir.c
> @@ -2153,10 +2153,12 @@ int ocfs2_empty_dir(struct inode *inode)
> {
> int ret;
> struct ocfs2_empty_dir_priv priv = {
> - .ctx.actor = ocfs2_empty_dir_filldir
> + .ctx.actor = ocfs2_empty_dir_filldir,
> + .ctx.pos = 0,
> };
>
> - memset(&priv, 0, sizeof(priv));
> + memset(&priv + sizeof(struct dir_context), 0,
> + sizeof(priv) - sizeof(struct dir_context));
>
> if (ocfs2_dir_indexed(inode)) {
> ret = ocfs2_empty_dir_dx(inode, &priv);
>
> > Hi,
> >
> > we reproducibly run into a NULL pointer dereference in OCFS2 on Linux
> > 3.11.0- rc2
> > It always happens if we try to copy or delete directories.
> >
> > The Filesystem was created with:
> > mkfs.ocfs2 -b 4K -C 1M -J block64 -L kvm-images -T vmstore /dev/drbd0
> >
> > cat /etc/ocfs2/cluster.conf :
> > cluster:
> > heartbeat_mode = global
> > node_count = 2
> > name = kvm
> >
> > node:
> > number = 0
> > cluster = kvm
> > ip_port = 7777
> > ip_address = 192.168.100.229
> > name = dinah
> >
> > node:
> > number = 1
> > cluster = kvm
> > ip_port = 7777
> > ip_address = 192.168.100.228
> > name = alice
> >
> >
> > dmesg:
> > [ 42.191816] BUG: unable to handle kernel NULL pointer dereference at
> > (null) [ 42.192753] IP: [< (null)>] (null)
> > [ 42.193348] PGD 79c1f9067 PUD 79c38a067 PMD 0
> > [ 42.193913] Oops: 0010 [#1] SMP
> > [ 42.194338] Modules linked in: ebtable_nat ebtables ocfs2_stack_o2cb
> > bridge stp llc kvm_intel kvm drbd lru_cache dlm sctp libcrc32c ocfs2_dlm
> > ocfs2_dlmfs ocfs2 ocfs2_stackglue ocfs2_nodemanager configfs e1000e
> > [ 42.196944] CPU: 1 PID: 2392 Comm: rm Not tainted 3.11.0-rc2 #19
> > [ 42.197617] Hardware name: Supermicro X8DT6/X8DT6, BIOS 2.0a 09/14/2010
> > [ 42.198389] task: ffff880799d06320 ti: ffff88079c664000 task.ti:
> > ffff88079c664000 [ 42.199251] RIP: 0010:[<0000000000000000>] [< (null)>]
> > (null)
> > [ 42.200545] RSP: 0018:ffff88079c665c30 EFLAGS: 00010293
> > [ 42.201394] RAX: 0000000000000002 RBX: 0000000000000010 RCX:
> > 0000000000000000 [ 42.202190] RDX: 0000000000000001 RSI: ffff88079290c0d4
> > RDI: ffff88079c665ce8 [ 42.202995] RBP: ffff88079c665ca8 R08:
> > 00000000000ea90e R09: 0000000000000004 [ 42.203794] R10: 0000000000000000
> > R11: 0000000000000000 R12: ffff88079290c0c0 [ 42.204600] R13:
> > ffff88079c665ce8 R14: ffff88079290c0c8 R15: ffff8807960ba598 [ 42.205406]
> > FS: 00007f4b6d259700(0000) GS:ffff8807a1220000(0000)
> > knlGS:0000000000000000
> > [ 42.206115] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> > [ 42.206453] CR2: 0000000000000000 CR3: 000000079b02a000 CR4:
> > 00000000000007e0 [ 42.207045] Stack:
> > [ 42.207266] ffffffffa00d8947 ffff88079c665e18 ffff8807960ba2c0
> > ffff88079c665c78 [ 42.208184] ffff88079290c0c0 ffff88079290c000
> > ffff88079c665cc0 ffff8807960ba598 [ 42.209089] ffff8807961269c0
> > ffff88079c665c88 ffff8807960ba598 00000000ffffffd9 [ 42.210298] Call
> > Trace:
> > [ 42.210579] [] ? ocfs2_dir_foreach_blk_id+0x169/0x212 [ocfs2]
> > [ 42.211419] [] ocfs2_dir_foreach+0x3a/0x3e [ocfs2]
> > [ 42.212145] [] ocfs2_empty_dir+0x148/0x391 [ocfs2]
> > [ 42.212880] [] ocfs2_unlink+0x567/0xbc3 [ocfs2]
> > [ 42.213573] [] ? __ocfs2_cluster_unlock.isra.41+0x89/0xbb [ocfs2]
> > [ 42.214463] [] vfs_rmdir+0xb0/0xfe
> > [ 42.215039] [] do_rmdir+0x143/0x19b
> > [ 42.215611] [] ? task_work_run+0x86/0xac
> > [ 42.216232] [] SyS_unlinkat+0x25/0x27
> > [ 42.216818] [] system_call_fastpath+0x16/0x1b
> > [ 42.217487] Code: Bad RIP value.
> > [ 42.217901] RIP [< (null)>] (null)
> > [ 42.218509] RSP
> > [ 42.218896] CR2: 0000000000000000
> > [ 42.219352] ---[ end trace 1c32c45da41ce169 ]---
> >
> >
> > The dereference happens here:
> > Reading symbols from /usr/src/linux-3.11-rc2/fs/ocfs2/dir.o...done.
> > (gdb) list *(ocfs2_dir_foreach_blk_id+0x169)
> > 0x4497 is in ocfs2_dir_foreach_blk_id (fs/ocfs2/dir.c:1820).
> > 1815 unsigned char d_type = DT_UNKNOWN;
> > 1816
> > 1817 if (de->file_type < OCFS2_FT_MAX)
> > 1818 d_type = ocfs2_filetype_table[de->file_type];
> > 1819
> > 1820 if (!dir_emit(ctx, de->name, de->name_len,
> > 1821 le64_to_cpu(de->inode), d_type))
> > 1822 goto out;
> > 1823 }
> > 1824 ctx->pos += le16_to_cpu(de->rec_len);
> >
> > Thanks in advance!
> >
> > Cheers,
> > David
> >
> > _______________________________________________
> > Ocfs2-devel mailing list
> > Ocfs2-devel at oss.oracle.com
> > https://oss.oracle.com/mailman/listinfo/ocfs2-devel
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