From 5366ae12b9ba60404822f6b39b41f6c0d98a7c8a Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 9 Apr 2023 15:18:55 +0200 Subject: [PATCH] avcodec/escape124: Check that blocks are allocated before use Fixes: NULL pointer dereference Fixes: 57819/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ESCAPE124_fuzzer-5077280228769792 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/escape124.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/escape124.c b/libavcodec/escape124.c index e8a8395f4b..592de09a9f 100644 --- a/libavcodec/escape124.c +++ b/libavcodec/escape124.c @@ -155,7 +155,7 @@ static MacroBlock decode_macroblock(Escape124Context* s, GetBitContext* gb, // This condition can occur with invalid bitstreams and // *codebook_index == 2 - if (block_index >= s->codebooks[*codebook_index].size) + if (block_index >= s->codebooks[*codebook_index].size || !s->codebooks[*codebook_index].blocks) return (MacroBlock) { { 0 } }; return s->codebooks[*codebook_index].blocks[block_index];