PR #20250 opened by Marvin Scholz (ePirat) URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20250 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20250.patch
The previous fix in 0ffe97d9b9e10e88db29d8d910c24ec00ef24edc only checked the count, which is not sufficient. In case there is an invalid (for example truncated) STSZ/STZ2 box, the previously allocated sample_sizes array will be freed. If then another STSZ box is encountered with a non-zero sample_size, the sample_count will be written without a new sample_sizes array being allocated. Fixes: NULL pointer dereference Fixes: 437528618/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6537287645331456 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg >From 3ebb021ebd9703eaa6d1106eaebc2e358dcb3e32 Mon Sep 17 00:00:00 2001 From: Marvin Scholz <epira...@gmail.com> Date: Fri, 15 Aug 2025 23:05:53 +0200 Subject: [PATCH] avformat/mov: Check that sample_sizes is allocated The previous fix in 0ffe97d9b9e10e88db29d8d910c24ec00ef24edc only checked the count, which is not sufficient. In case there is an invalid (for example truncated) STSZ/STZ2 box, the previously allocated sample_sizes array will be freed. If then another STSZ box is encountered with a non-zero sample_size, the sample_count will be written without a new sample_sizes array being allocated. Fixes: NULL pointer dereference Fixes: 437528618/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6537287645331456 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg --- libavformat/mov.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavformat/mov.c b/libavformat/mov.c index 86037c6712..d6fcb0c5dc 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -10472,7 +10472,7 @@ static int mov_parse_heif_items(AVFormatContext *s) st->codecpar->height = item->height; err = sanity_checks(s, sc, item->item_id); - if (err || !sc->sample_count) + if (err || !sc->sample_sizes) return AVERROR_INVALIDDATA; sc->sample_sizes[0] = item->extent_length; -- 2.49.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
