From d51d569cf68f78aaea8464a156c847a0e294726a Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 6 Aug 2020 21:35:06 +0200 Subject: [PATCH] avcodec/snowdec: Sanity check hcoeff Fixes: signed integer overflow: -2147483648 * -1 cannot be represented in type 'int' Fixes: 24011/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SNOW_fuzzer-5486376610168832 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/snowdec.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/libavcodec/snowdec.c b/libavcodec/snowdec.c index 88664dc472..5e69f39022 100644 --- a/libavcodec/snowdec.c +++ b/libavcodec/snowdec.c @@ -369,7 +369,10 @@ static int decode_header(SnowContext *s){ htaps = htaps*2 + 2; p->htaps= htaps; for(i= htaps/2; i; i--){ - p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1)); + unsigned hcoeff = get_symbol(&s->c, s->header_state, 0); + if (hcoeff > 127) + return AVERROR_INVALIDDATA; + p->hcoeff[i]= hcoeff * (1-2*(i&1)); sum += p->hcoeff[i]; } p->hcoeff[0]= 32-sum;