The compat ioctl for VIDEO_SET_SPU_PALETTE was missing an error check while converting ioctl arguments. This could lead to leaking kernel stack contents into userspace. Patch extracted from existing fix in grsecurity. Cc: David Miller <davem@xxxxxxxxxxxxx> Cc: Brad Spengler <spender@xxxxxxxxxxxxxx> Cc: PaX Team <pageexec@xxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- fs/compat_ioctl.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index f505402..4c6285f 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -210,6 +210,8 @@ static int do_video_set_spu_palette(unsigned int fd, unsigned int cmd, err = get_user(palp, &up->palette); err |= get_user(length, &up->length); + if (err) + return -EFAULT; up_native = compat_alloc_user_space(sizeof(struct video_spu_palette)); err = put_user(compat_ptr(palp), &up_native->palette); -- 1.7.9.5 -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
