nilfs2: fix crash after one superblock became unavailable
commit468f3e11a872a4f83009e5128e0a3c0e287a5633
authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Fri, 21 Jan 2011 07:40:31 +0000 (21 16:40 +0900)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 17 Feb 2011 23:14:59 +0000 (17 15:14 -0800)
tree12712a35ae9dff929a0d5dacbce8621b0a4ac63a
parent5b33c4a2720e314ac4c23589a301b378c13a6606
nilfs2: fix crash after one superblock became unavailable

commit 0ca7a5b9ac5d301845dd6382ff25a699b6263a81 upstream.

Fixes the following kernel oops in nilfs_setup_super() which could
arise if one of two super-blocks is unavailable.

> BUG: unable to handle kernel NULL pointer dereference at   (null)
> Pid: 3529, comm: mount.nilfs2 Not tainted 2.6.37 #1 /
> EIP: 0060:[<c03196bc>] EFLAGS: 00010202 CPU: 3
> EIP is at memcpy+0xc/0x1b
> Call Trace:
>  [<f953720e>] ? nilfs_setup_super+0x6c/0xa5 [nilfs2]
>  [<f95369e9>] ? nilfs_get_root_dentry+0x81/0xcb [nilfs2]
>  [<f9537a08>] ? nilfs_mount+0x4f9/0x62c [nilfs2]
>  [<c02745cf>] ? kstrdup+0x36/0x3f
>  [<f953750f>] ? nilfs_mount+0x0/0x62c [nilfs2]
>  [<c0293940>] ? vfs_kern_mount+0x4d/0x12c
>  [<c02a5100>] ? get_fs_type+0x76/0x8f
>  [<c0293a68>] ? do_kern_mount+0x33/0xbf
>  [<c02a784a>] ? do_mount+0x2ed/0x714
>  [<c02a6171>] ? copy_mount_options+0x28/0xfc
>  [<c02a7ce3>] ? sys_mount+0x72/0xaf
>  [<c0473085>] ? syscall_call+0x7/0xb

Reported-by: Wakko Warner <wakko@animx.eu.org>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Wakko Warner <wakko@animx.eu.org>
LKML-Reference: <20110121024918.GA29598@animx.eu.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fs/nilfs2/super.c