From patchwork Thu Jun 27 00:35:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Niedermayer X-Patchwork-Id: 13709 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 B4D364499F0 for ; Thu, 27 Jun 2019 03:37:31 +0300 (EEST) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 8E68C68A905; Thu, 27 Jun 2019 03:37:31 +0300 (EEST) X-Original-To: ffmpeg-devel@ffmpeg.org Delivered-To: ffmpeg-devel@ffmpeg.org Received: from vie01a-dmta-pe06-3.mx.upcmail.net (vie01a-dmta-pe06-3.mx.upcmail.net [84.116.36.16]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 35338681852 for ; Thu, 27 Jun 2019 03:37:25 +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 1hgIPk-00085S-1u for ffmpeg-devel@ffmpeg.org; Thu, 27 Jun 2019 02:37:24 +0200 Received: from localhost ([213.47.41.20]) by vie01a-pemc-psmtp-pe12.mail.upcmail.net with ESMTP id gIOlhz7h85D5NgIOlhlvrW; Thu, 27 Jun 2019 02:36:24 +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=MKtGQD3n3ToA:10 a=1oJP67jkp3AA:10 a=GEAsPZ9sns4A:10 a=ZZnuYtJkoWoA:10 a=nZOtpAppAAAA:20 a=Z_vbiudBpHXRjz_E9wQA:9 a=1fhp2MxaeJtTNGEnv6mo:22 a=pHzHmUro8NiASowvMSCR:22 a=nt3jZW36AmriUCFCBwmW:22 From: Michael Niedermayer To: FFmpeg development discussions and patches Date: Thu, 27 Jun 2019 02:35:30 +0200 Message-Id: <20190627003533.22314-1-michael@niedermayer.cc> X-Mailer: git-send-email 2.22.0 MIME-Version: 1.0 X-CMAE-Envelope: MS4wfGuTX6HEjoy4V/CFpxJC3zQO25UCpK0hs0UzpG2ZsRrR8vSD17WgU17fCUuh3VBnId/jyCImDguBiSf0yIH0CcR3G2ygF19q3OwGDnV6tp0cDhVzyvvY kViVtTb38DZsAXVD6wDMKoRpF/O9NCB06bwmVvrWxEiFbfOSBtDKQxVL Subject: [FFmpeg-devel] [PATCH 1/4] avformat/vividas: Check for input length in get_v() 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: out of array read Fixes: 15286/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5658245101780992 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/vividas.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/libavformat/vividas.c b/libavformat/vividas.c index 753328245d..350c7aa70a 100644 --- a/libavformat/vividas.c +++ b/libavformat/vividas.c @@ -178,12 +178,13 @@ static void decode_block(uint8_t *src, uint8_t *dest, unsigned size, } } -static uint32_t get_v(uint8_t *p) +static uint32_t get_v(uint8_t *p, int len) { uint32_t v = 0; + const uint8_t *end = p + len; do { - if (v >= UINT_MAX / 128 - *p) + if (p >= end || v >= UINT_MAX / 128 - *p) return v; v <<= 7; v += *p & 0x7f; @@ -204,7 +205,7 @@ static uint8_t *read_vblock(AVIOContext *src, uint32_t *size, decode_block(tmp, tmp, 4, key, k2, align); - n = get_v(tmp); + n = get_v(tmp, 4); if (n < 4) return NULL; @@ -241,13 +242,13 @@ static uint8_t *read_sb_block(AVIOContext *src, unsigned *size, k2 = *key; decode_block(ibuf, sbuf, 8, *key, &k2, 0); - n = get_v(sbuf+2); + n = get_v(sbuf+2, 6); if (sbuf[0] != 'S' || sbuf[1] != 'B' || (expected_size>0 && n != expected_size)) { uint32_t tmpkey = recover_key(ibuf, expected_size); k2 = tmpkey; decode_block(ibuf, sbuf, 8, tmpkey, &k2, 0); - n = get_v(sbuf+2); + n = get_v(sbuf+2, 6); if (sbuf[0] != 'S' || sbuf[1] != 'B' || expected_size != n) return NULL; *key = tmpkey;