This patch fixes a crash issue recently reported by Wakko Warner. I will send this upstream and to stable after a while. Ryusuke Konishi -- From: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx> 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@xxxxxxxxxxxx> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx> Tested-by: Wakko Warner <wakko@xxxxxxxxxxxx> Cc: stable <stable@xxxxxxxxxx> [2.6.37, 2.6.36] LKML-Reference: <20110121024918.GA29598@xxxxxxxxxxxx> --- fs/nilfs2/super.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 0994f6a7..58fd707 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); } -- 1.7.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
