From 393d6fc7395611a38792e3c271b2be42ac45e672 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 13 Oct 2017 03:06:54 +0200 Subject: [PATCH] avcodec/snowdec: Check mv_scale Fixes: runtime error: signed integer overflow: 2 * -1094995530 cannot be represented in type 'int' Fixes: 3512/clusterfuzz-testcase-minimized-4812747210489856 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/snowdec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/libavcodec/snowdec.c b/libavcodec/snowdec.c index b74c468ce3..13668c2105 100644 --- a/libavcodec/snowdec.c +++ b/libavcodec/snowdec.c @@ -394,9 +394,10 @@ static int decode_header(SnowContext *s){ s->mv_scale += get_symbol(&s->c, s->header_state, 1); s->qbias += get_symbol(&s->c, s->header_state, 1); s->block_max_depth+= get_symbol(&s->c, s->header_state, 1); - if(s->block_max_depth > 1 || s->block_max_depth < 0){ + if(s->block_max_depth > 1 || s->block_max_depth < 0 || s->mv_scale > 256U){ av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth); s->block_max_depth= 0; + s->mv_scale = 0; return AVERROR_INVALIDDATA; } if (FFABS(s->qbias) > 127) {