From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47892C71122 for ; Sun, 14 Oct 2018 15:30:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1805D2145D for ; Sun, 14 Oct 2018 15:30:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1805D2145D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726928AbeJNXLk (ORCPT ); Sun, 14 Oct 2018 19:11:40 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35591 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726623AbeJNXLj (ORCPT ); Sun, 14 Oct 2018 19:11:39 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1gBiLS-0004cH-Dz; Sun, 14 Oct 2018 16:30:18 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLN-00008f-5p; Sun, 14 Oct 2018 16:30:13 +0100 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, "Michal Srb" , "Chris Wilson" Date: Sun, 14 Oct 2018 16:25:40 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 004/366] drm/i915/cmdparser: Do not check past the cmd length. In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Michal Srb commit 3aec7f871c65eb5f76b4125fda432593c834a6f2 upstream. The command MEDIA_VFE_STATE checks bits at offset +2 dwords. However, it is possible to have MEDIA_VFE_STATE command with length = 0 + LENGTH_BIAS = 2. In that case check_cmd will read bits from the following command, or even past the end of the buffer. If the offset ends up outside of the command length, reject the command. Fixes: 351e3db2b363 ("drm/i915: Implement command buffer parsing logic") Signed-off-by: Michal Srb Link: https://patchwork.freedesktop.org/patch/msgid/20180205151745.29292-1-msrb@suse.com Reviewed-by: Chris Wilson Signed-off-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/20180205160438.3267-2-chris@chris-wilson.co.uk [bwh: Backported to 3.16: Log ring->id rather than engine->name] Signed-off-by: Ben Hutchings --- drivers/gpu/drm/i915/i915_cmd_parser.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -941,6 +941,12 @@ static bool check_cmd(const struct intel continue; } + if (desc->bits[i].offset >= length) { + DRM_DEBUG_DRIVER("CMD: Rejected command 0x%08X, too short to check bitmask (ring=%d)\n", + *cmd, ring->id); + return false; + } + dword = cmd[desc->bits[i].offset] & desc->bits[i].mask;