From patchwork Mon Sep 9 20:16:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 14989 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 1F3744486EC for ; Mon, 9 Sep 2019 23:17:40 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 0BB64687FBB; Mon, 9 Sep 2019 23:17:40 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe05-3.mx.upcmail.net (vie01a-dmta-pe05-3.mx.upcmail.net [84.116.36.13]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id C6F8368077C for ; Mon, 9 Sep 2019 23:17:32 +0300 (EEST) Received: from [172.31.216.235] (helo=vie01a-pemc-psmtp-pe12.mail.upcmail.net) by vie01a-dmta-pe05.mx.upcmail.net with esmtp (Exim 4.92) (envelope-from ) id 1i7Q6O-0005b4-1k for ffmpeg-devel@ffmpeg.org; Mon, 09 Sep 2019 22:17:32 +0200 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id 7Q5Oi0Zqvwlys7Q5PiUaE2; Mon, 09 Sep 2019 22:16:31 +0200 X-Env-Mailfrom: michael@niedermayer.cc X-Env-Rcptto: ffmpeg-devel@ffmpeg.org X-SourceIP: 213.47.68.29 X-CNFS-Analysis: v=2.3 cv=E5OzWpVl c=1 sm=1 tr=0 a=2hcxjKEKjp0CzLx6oWAm4g==:117 a=2hcxjKEKjp0CzLx6oWAm4g==:17 a=IkcTkHD0fZMA:10 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=Rv83ztLi7FEx18xP6UYA:9 a=QEXdDO2ut3YA:10 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=jd6J4Gguk5HxikPWLKER:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Mon, 9 Sep 2019 22:16:20 +0200 Message-Id: <20190909201621.14091-1-michael@niedermayer.cc> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-CMAE-Envelope: MS4wfFt2L9LCyjO4meNjC3wyVpkzU+ee+oIeYAeNtXfVICN1U9CLAFsOlyRQMsKri3mOCkIpjzVMRSr5PGMuD0F1Lb79h7RPM5KYXJ2rDVF6/agEZMClaMKZ 1NvC2A7nXWdngRgHShJF/pPSBJQduHEDtPJnZWJCvdV3wRz8XbJCqFNp Subject: [FFmpeg-devel] [PATCH 1/2] avcodec/g2meet: Check if adjusted pixel was on the stack 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" This basically checks if a pixel that was coded with prediction and residual could have been stored using a previous case. This avoids basically a string of 0 symbols stored in less than 50 bytes to hit a O(n²) codepath. Fixes: Timeout (too slow to wait -> immedeatly) Fixes: 8668/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_G2M_fuzzer-4895946310680576 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/g2meet.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libavcodec/g2meet.c b/libavcodec/g2meet.c index a1dec8d823..19e1c130ce 100644 --- a/libavcodec/g2meet.c +++ b/libavcodec/g2meet.c @@ -854,6 +854,9 @@ static int epic_decode_tile(ePICContext *dc, uint8_t *out, int tile_height, uint32_t ref_pix = curr_row[x - 1]; if (!x || !epic_decode_from_cache(dc, ref_pix, &pix)) { pix = epic_decode_pixel_pred(dc, x, y, curr_row, above_row); + if (is_pixel_on_stack(dc, pix)) + return AVERROR_INVALIDDATA; + if (x) { int ret = epic_add_pixel_to_cache(&dc->hash, ref_pix,