From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932327Ab2DFNct (ORCPT ); Fri, 6 Apr 2012 09:32:49 -0400 Received: from mail-qc0-f174.google.com ([209.85.216.174]:43506 "EHLO mail-qc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757256Ab2DFNcq (ORCPT ); Fri, 6 Apr 2012 09:32:46 -0400 From: Xi Wang To: Mauro Carvalho Chehab , Guennadi Liakhovetski Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Xi Wang Subject: [PATCH 2/2] [media] v4l2-ctrls: fix integer overflow in try_set_ext_ctrls() Date: Fri, 6 Apr 2012 09:32:37 -0400 Message-Id: <1333719157-31240-2-git-send-email-xi.wang@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1333719157-31240-1-git-send-email-xi.wang@gmail.com> References: <1333719157-31240-1-git-send-email-xi.wang@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A large cs->count from userspace may overflow the allocation size, leading to memory corruption. try_set_ext_ctrls() can be reached from subdev_do_ioctl() or __video_do_ioctl(). Use kmalloc_array() to avoid the overflow. Signed-off-by: Xi Wang --- drivers/media/video/v4l2-ctrls.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c index f355fd5..6f38a5d 100644 --- a/drivers/media/video/v4l2-ctrls.c +++ b/drivers/media/video/v4l2-ctrls.c @@ -2219,7 +2219,8 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl, return class_check(hdl, cs->ctrl_class); if (cs->count > ARRAY_SIZE(helper)) { - helpers = kmalloc(sizeof(helper[0]) * cs->count, GFP_KERNEL); + helpers = kmalloc_array(cs->count, sizeof(helper[0]), + GFP_KERNEL); if (!helpers) return -ENOMEM; } -- 1.7.5.4