From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754935Ab0IXQxm (ORCPT ); Fri, 24 Sep 2010 12:53:42 -0400 Received: from kroah.org ([198.145.64.141]:38364 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932681Ab0IXQ22 (ORCPT ); Fri, 24 Sep 2010 12:28:28 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Sep 24 09:26:18 2010 Message-Id: <20100924162618.446483373@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 24 Sep 2010 09:24:29 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Dan Rosenberg , Thomas Winischhofer Subject: [41/80] drivers/video/sis/sis_main.c: prevent reading uninitialized stack memory In-Reply-To: <20100924162706.GA7381@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-stable review patch. If anyone has any objections, please let us know. ------------------ From: Dan Rosenberg commit fd02db9de73faebc51240619c7c7f99bee9f65c7 upstream. The FBIOGET_VBLANK device ioctl allows unprivileged users to read 16 bytes of uninitialized stack memory, because the "reserved" member of the fb_vblank struct declared on the stack is not altered or zeroed before being copied back to the user. This patch takes care of it. Signed-off-by: Dan Rosenberg Cc: Thomas Winischhofer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/video/sis/sis_main.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/video/sis/sis_main.c +++ b/drivers/video/sis/sis_main.c @@ -1701,6 +1701,9 @@ static int sisfb_ioctl(struct fb_info *i break; case FBIOGET_VBLANK: + + memset(&sisvbblank, 0, sizeof(struct fb_vblank)); + sisvbblank.count = 0; sisvbblank.flags = sisfb_setupvbblankflags(ivideo, &sisvbblank.vcount, &sisvbblank.hcount);