[Ocfs2-devel] NULL pointer dereference at ocfs2_dir_foreach_blk_id
Jeff Liu
jeff.liu at oracle.com
Mon Jul 29 03:50:10 PDT 2013
Hi David,
Thanks for your report, could you try the fix below?
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);
--
1.7.9.5
On 07/25/2013 06:13 PM, David Weber wrote:
> 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
>
> _______________________________________________
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