From patchwork Wed Sep 25 20:38:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 15293 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 D1ADA447690 for ; Wed, 25 Sep 2019 23:40:37 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id B83E5689FB8; Wed, 25 Sep 2019 23:40:37 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe05-1.mx.upcmail.net (vie01a-dmta-pe05-1.mx.upcmail.net [84.116.36.11]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id F3BF5689DA5 for ; Wed, 25 Sep 2019 23:40:28 +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 1iDE5M-0009dz-CK for ffmpeg-devel@ffmpeg.org; Wed, 25 Sep 2019 22:40:28 +0200 Received: from localhost ([213.47.68.29]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id DE4OioHwFwlysDE4Oi8AhT; Wed, 25 Sep 2019 22:39:28 +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=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=FQBnv-yHQK9mrEHaCl4A:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=Z5ABNNGmrOfJ6cZ5bIyy:22 a=UDnyf2zBuKT2w-IlGP_r:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Wed, 25 Sep 2019 22:38:49 +0200 Message-Id: <20190925203858.27870-3-michael@niedermayer.cc> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190925203858.27870-1-michael@niedermayer.cc> References: <20190925203858.27870-1-michael@niedermayer.cc> MIME-Version: 1.0 X-CMAE-Envelope: MS4wfN2CAsAESXwqRb58V1ZCM8vbmDUdiCv6Z+tVWD3Im4SMVM/3u/NeBha26ifCEqAJd+nnV3c7O/2+FMicZ1DYE0z+X5o3YuSuriX+cP/JEYD3vrN5Z3C4 yZrAmeCrsTXjGVbMFdORV8ATblNUQILArPS0HRryaY6k6UvWmiq7G8eh Subject: [FFmpeg-devel] [PATCH 03/12] avcodec/fitsdec: Prevent division by 0 with huge data_max 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: division by 0 Fixes: 15657/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FITS_fuzzer-5738154838982656 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/fitsdec.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/libavcodec/fitsdec.c b/libavcodec/fitsdec.c index 4f452422ef..88b841a964 100644 --- a/libavcodec/fitsdec.c +++ b/libavcodec/fitsdec.c @@ -195,6 +195,7 @@ static int fits_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, uint8_t *dst8; uint16_t *dst16; uint64_t t; + double scale; FITSHeader header; FITSContext * fitsctx = avctx->priv_data; @@ -204,6 +205,12 @@ static int fits_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, if (ret < 0) return ret; + scale = header.data_max - header.data_min; + if (scale <= 0 || !isfinite(scale)) { + scale = 1; + } + scale = 1/scale; + if (header.rgb) { if (header.bitpix == 8) { if (header.naxisn[2] == 3) { @@ -272,7 +279,7 @@ static int fits_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, for (j = 0; j < avctx->width; j++) { \ t = rd; \ if (!header.blank_found || t != header.blank) { \ - *dst++ = ((t - header.data_min) * ((1 << (sizeof(type) * 8)) - 1)) / (header.data_max - header.data_min); \ + *dst++ = ((t - header.data_min) * ((1 << (sizeof(type) * 8)) - 1)) * scale; \ } else { \ *dst++ = fitsctx->blank_val; \ } \