From b9948d52756a883afb1e7cebf9740f1094e1f3f3 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 15 Jan 2018 03:03:36 +0100 Subject: [PATCH] avcodec/snowdec: Fix integer overflow before htaps check Fixes: runtime error: signed integer overflow: -1094995529 * 2 cannot be represented in type 'int' Fixes: 4828/clusterfuzz-testcase-minimized-5100849937252352 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 2eecf3cf8eeae67697934df326e98df2149881e5) Signed-off-by: Michael Niedermayer --- libavcodec/snowdec.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/libavcodec/snowdec.c b/libavcodec/snowdec.c index 4506c9b815..fc917e0c35 100644 --- a/libavcodec/snowdec.c +++ b/libavcodec/snowdec.c @@ -360,9 +360,10 @@ static int decode_header(SnowContext *s){ int htaps, i, sum=0; Plane *p= &s->plane[plane_index]; p->diag_mc= get_rac(&s->c, s->header_state); - htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2; - if((unsigned)htaps >= HTAPS_MAX || htaps==0) + htaps= get_symbol(&s->c, s->header_state, 0); + if((unsigned)htaps >= HTAPS_MAX/2 - 1) return AVERROR_INVALIDDATA; + 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));