From 8652f4e7a15e56fadf9697188c1ed42c9981db82 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 3 Jan 2020 23:24:15 +0100 Subject: avcodec/iff: Over-allocate ham_palbuf for HAM6 IFF-PBM IFF-PBM-HAM6 can read out of array without this overallocation Fixes: Out of array read Fixes: 19752/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IFF_ILBM_fuzzer-5675331403120640 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/iff.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'libavcodec/iff.c') diff --git a/libavcodec/iff.c b/libavcodec/iff.c index d826e78089..acd6519b06 100644 --- a/libavcodec/iff.c +++ b/libavcodec/iff.c @@ -332,13 +332,17 @@ static int extract_header(AVCodecContext *const avctx, int i, count = FFMIN(palette_size / 3, 1 << s->ham); int ham_count; const uint8_t *const palette = avctx->extradata + AV_RB16(avctx->extradata); + int extra_space = 1; + + if (avctx->codec_tag == MKTAG('P', 'B', 'M', ' ') && s->ham == 4) + extra_space = 4; s->ham_buf = av_malloc((s->planesize * 8) + AV_INPUT_BUFFER_PADDING_SIZE); if (!s->ham_buf) return AVERROR(ENOMEM); ham_count = 8 * (1 << s->ham); - s->ham_palbuf = av_malloc((ham_count << !!(s->masking == MASK_HAS_MASK)) * sizeof (uint32_t) + AV_INPUT_BUFFER_PADDING_SIZE); + s->ham_palbuf = av_malloc(extra_space * (ham_count << !!(s->masking == MASK_HAS_MASK)) * sizeof (uint32_t) + AV_INPUT_BUFFER_PADDING_SIZE); if (!s->ham_palbuf) { av_freep(&s->ham_buf); return AVERROR(ENOMEM); -- cgit v1.2.3