3.16.63-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Filipe Manana <[email protected]> commit f505754fd6599230371cb01b9332754ddc104be1 upstream. We were using the path name received from user space without checking that it is null terminated. While btrfs-progs is well behaved and does proper validation and null termination, someone could call the ioctl and pass a non-null terminated patch, leading to buffer overrun problems in the kernel. The ioctl is protected by CAP_SYS_ADMIN. So just set the last byte of the path to a null character, similar to what we do in other ioctls (add/remove/resize device, snapshot creation, etc). Reviewed-by: Anand Jain <[email protected]> Signed-off-by: Filipe Manana <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- fs/btrfs/super.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1771,6 +1771,7 @@ static long btrfs_control_ioctl(struct f vol = memdup_user((void __user *)arg, sizeof(*vol)); if (IS_ERR(vol)) return PTR_ERR(vol); + vol->name[BTRFS_PATH_NAME_MAX] = '\0'; switch (cmd) { case BTRFS_IOC_SCAN_DEV:
