From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755070AbdKGOFM (ORCPT ); Tue, 7 Nov 2017 09:05:12 -0500 Received: from baptiste.telenet-ops.be ([195.130.132.51]:49424 "EHLO baptiste.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752617AbdKGOFK (ORCPT ); Tue, 7 Nov 2017 09:05:10 -0500 From: Geert Uytterhoeven To: Bartlomiej Zolnierkiewicz Cc: Dan Carpenter , Benjamin Herrenschmidt , linux-fbdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Geert Uytterhoeven Subject: [PATCH] fbdev: controlfb: Add missing modes to fix out of bounds access Date: Tue, 7 Nov 2017 15:05:05 +0100 Message-Id: <1510063505-2063-1-git-send-email-geert@linux-m68k.org> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dan's static analysis says: drivers/video/fbdev/controlfb.c:560 control_setup() error: buffer overflow 'control_mac_modes' 20 <= 21 Indeed, control_mac_modes[] has only 20 elements, while VMODE_MAX is 22, which may lead to an out of bounds read when parsing vmode commandline options. The bug was introduced in v2.4.5.6, when 2 new modes were added to macmodes.h, but control_mac_modes[] wasn't updated: https://kernel.opensuse.org/cgit/kernel/diff/include/video/macmodes.h?h=v2.5.2&id=29f279c764808560eaceb88fef36cbc35c529aad Augment control_mac_modes[] with the two new video modes to fix this. Reported-by: Dan Carpenter Signed-off-by: Geert Uytterhoeven --- Compile-tested only. The 1152x768 mode should be OK. Given the 1600x1024 mode has a lower dotclock (112 MHz) than the supported 1280x960 mode, it's probably OK, too. --- drivers/video/fbdev/controlfb.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/video/fbdev/controlfb.h b/drivers/video/fbdev/controlfb.h index 6026c60fc1007e00..261522fabdac89ae 100644 --- a/drivers/video/fbdev/controlfb.h +++ b/drivers/video/fbdev/controlfb.h @@ -141,5 +141,7 @@ static struct max_cmodes control_mac_modes[] = { {{ 1, 2}}, /* 1152x870, 75Hz */ {{ 0, 1}}, /* 1280x960, 75Hz */ {{ 0, 1}}, /* 1280x1024, 75Hz */ + {{ 1, 2}}, /* 1152x768, 60Hz */ + {{ 0, 1}}, /* 1600x1024, 60Hz */ }; -- 2.7.4