From patchwork Thu Aug 1 21:44:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 14185 Return-Path: X-Original-To: patchwork@ffaux-bg.ffmpeg.org Delivered-To: patchwork@ffaux-bg.ffmpeg.org Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by ffaux.localdomain (Postfix) with ESMTP id 7337C447E7E for ; Fri, 2 Aug 2019 00:46:23 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 5C1EA68ABC0; Fri, 2 Aug 2019 00:46:23 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe06-2.mx.upcmail.net (vie01a-dmta-pe06-2.mx.upcmail.net [84.116.36.15]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 8065968A362 for ; Fri, 2 Aug 2019 00:46:16 +0300 (EEST) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe06.mx.upcmail.net with esmtp (Exim 4.92) (envelope-from ) id 1htIts-0005Nc-2B for ffmpeg-devel@ffmpeg.org; Thu, 01 Aug 2019 23:46:16 +0200 Received: from localhost ([213.47.41.20]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id tIsuhTE2b5D5NtIsuhm8oV; Thu, 01 Aug 2019 23:45:16 +0200 X-Env-Mailfrom: michael@niedermayer.cc X-Env-Rcptto: ffmpeg-devel@ffmpeg.org X-SourceIP: 213.47.41.20 X-CNFS-Analysis: v=2.3 cv=bu8y+3Si c=1 sm=1 tr=0 a=I1eytVlZLDX1BM2VTtTtSw==:117 a=I1eytVlZLDX1BM2VTtTtSw==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=1aYfqZZPwnZEA7LgRqkA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=SsAZrZ5W_gNWK9tOzrEV:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Thu, 1 Aug 2019 23:44:42 +0200 Message-Id: <20190801214443.7695-4-michael@niedermayer.cc> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190801214443.7695-1-michael@niedermayer.cc> References: <20190801214443.7695-1-michael@niedermayer.cc> MIME-Version: 1.0 X-CMAE-Envelope: MS4wfNY1oT4jhzgPhWZYDp/4k/3+tPzJbvytBIjIqCinLtqaBEZF9jf9uNY2PrJWmA17sWWgJeZlFk+Lh21loH0c3IhAbc1cnOavISbZ4eRZJWw3qJ4SWEn8 A0T7tRXC8b/tx38B+NMURBpwL/g8nFAQAzzt0za6S1lth7dnoBZ+pRQJ Subject: [FFmpeg-devel] [PATCH 4/5] avcodec/parser: Optimize ff_combine_frame() with massivly negative next X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Fixes: Timeout Fixes: 15558/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PPM_fuzzer-5705273643106304 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/parser.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/parser.c b/libavcodec/parser.c index 3e19810a94..a63f532c48 100644 --- a/libavcodec/parser.c +++ b/libavcodec/parser.c @@ -295,6 +295,10 @@ int ff_combine_frame(ParseContext *pc, int next, *buf = pc->buffer; } + if (next < -8) { + pc->overread += -8 - next; + next = -8; + } /* store overread bytes */ for (; next < 0; next++) { pc->state = pc->state << 8 | pc->buffer[pc->last_index + next];