From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [RESEND][PATCH] compat: VIDEO_SET_SPU_PALETTE missing error check Date: Wed, 24 Oct 2012 13:59:04 -0700 Message-ID: <20121024205904.GA12495@www.outflux.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, Andrew Morton , David Miller , Brad Spengler , PaX Team To: linux-kernel@vger.kernel.org Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org 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: Andrew Morton Cc: David Miller Cc: Brad Spengler Cc: PaX Team Cc: stable@vger.kernel.org Signed-off-by: Kees Cook --- 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