Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760114AbaLLG6Y (ORCPT ); Fri, 12 Dec 2014 01:58:24 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51729 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758621AbaLLGQy (ORCPT ); Fri, 12 Dec 2014 01:16:54 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Maciej Matraszek" , "Sakari Ailus" , "Mauro Carvalho Chehab" Date: Fri, 12 Dec 2014 06:14:25 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 015/164] [media] v4l2-common: fix overflow in v4l_bound_align_image() In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:c97:8151:cc89:c28d X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.65-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Maciej Matraszek commit 3bacc10cd4a85bc70bc0b6c001d3bf995c7fe04c upstream. Fix clamp_align() used in v4l_bound_align_image() to prevent overflow when passed large value like UINT32_MAX. In the current implementation: clamp_align(UINT32_MAX, 8, 8192, 3) returns 8, because in line: x = (x + (1 << (align - 1))) & mask; x overflows to (-1 + 4) & 0x7 = 3, while expected value is 8192. v4l_bound_align_image() is heavily used in VIDIOC_S_FMT and VIDIOC_SUBDEV_S_FMT ioctls handlers, and documentation of the latter explicitly states that: "The modified format should be as close as possible to the original request." -- http://linuxtv.org/downloads/v4l-dvb-apis/vidioc-subdev-g-fmt.html Thus one would expect, that passing UINT32_MAX as format width and height will result in setting maximum possible resolution for the device. Particularly, when the driver doesn't support VIDIOC_ENUM_FRAMESIZES ioctl, which is common in the codebase. Fixes changeset: b0d3159be9a3 Signed-off-by: Maciej Matraszek Acked-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings --- drivers/media/video/v4l2-common.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) --- a/drivers/media/video/v4l2-common.c +++ b/drivers/media/video/v4l2-common.c @@ -487,16 +487,13 @@ static unsigned int clamp_align(unsigned /* Bits that must be zero to be aligned */ unsigned int mask = ~((1 << align) - 1); + /* Clamp to aligned min and max */ + x = clamp(x, (min + ~mask) & mask, max & mask); + /* Round to nearest aligned value */ if (align) x = (x + (1 << (align - 1))) & mask; - /* Clamp to aligned value of min and max */ - if (x < min) - x = (min + ~mask) & mask; - else if (x > max) - x = max & mask; - return x; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/