From 4e40e893cc1aad403ee03cecd8c4081c95fcef36 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 18 Jun 2024 15:48:23 +0200 Subject: [PATCH] avcodec/snowenc: MV limits due to mv_penalty table size Fixes: out of array read Fixes: 69673/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SNOW_fuzzer-5476592894148608 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 3a9292aff320d7b5048b371b1babea2f9b3c4e69) Signed-off-by: Michael Niedermayer --- libavcodec/snowenc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/libavcodec/snowenc.c b/libavcodec/snowenc.c index d81ff6f2aa..70a2de1671 100644 --- a/libavcodec/snowenc.c +++ b/libavcodec/snowenc.c @@ -411,6 +411,7 @@ static int encode_q_branch(SnowEncContext *enc, int level, int x, int y) int my_context= av_log2(2*FFABS(left->my - top->my)); int s_context= 2*left->level + 2*top->level + tl->level + tr->level; int ref, best_ref, ref_score, ref_mx, ref_my; + int range = MAX_MV >> (1 + qpel); av_assert0(sizeof(s->block_state) >= 256); if(s->keyframe){ @@ -452,6 +453,11 @@ static int encode_q_branch(SnowEncContext *enc, int level, int x, int y) c->xmax = - (x+1)*block_w + (w<<(LOG2_MB_SIZE - s->block_max_depth)) + 16-3; c->ymax = - (y+1)*block_w + (h<<(LOG2_MB_SIZE - s->block_max_depth)) + 16-3; + c->xmin = FFMAX(c->xmin,-range); + c->xmax = FFMIN(c->xmax, range); + c->ymin = FFMAX(c->ymin,-range); + c->ymax = FFMIN(c->ymax, range); + if(P_LEFT[0] > (c->xmax<xmax< (c->ymax<ymax< (c->xmax<xmax<