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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2011-01-21 16:40:31 +0900
committerRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2011-01-22 15:22:36 +0900
commit0ca7a5b9ac5d301845dd6382ff25a699b6263a81 (patch)
tree52d0ab285bd2dfabbba164a9df72468fdd92d29b /fs/nilfs2/super.c
parent1bae4ce27c9c90344f23c65ea6966c50ffeae2f5 (diff)
downloadlinux-0ca7a5b9ac5d301845dd6382ff25a699b6263a81.tar.bz2
nilfs2: fix crash after one superblock became unavailable
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> Cc: stable <stable@kernel.org> [2.6.37, 2.6.36] LKML-Reference: <20110121024918.GA29598@animx.eu.org>
Diffstat (limited to 'fs/nilfs2/super.c')
-rw-r--r--fs/nilfs2/super.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 0994f6a76c07..58fd707174e1 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -704,7 +704,8 @@ skip_mount_setup:
sbp[0]->s_state =
cpu_to_le16(le16_to_cpu(sbp[0]->s_state) & ~NILFS_VALID_FS);
/* synchronize sbp[1] with sbp[0] */
- memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
+ if (sbp[1])
+ memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
return nilfs_commit_super(sbi, NILFS_SB_COMMIT_ALL);
}