From dfa5d1a3667fa38e07373becc2401175b31d8228 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 21 Aug 2019 23:22:39 +0200 Subject: [PATCH] avcodec/iff: Check for overlap in cmap_read_palette() Fixes: undefined memcpy() use Fixes: 16302/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IFF_ILBM_fuzzer-5678750575886336 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/iff.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/iff.c b/libavcodec/iff.c index fc7bfad731d..c18bac1ea18 100644 --- a/libavcodec/iff.c +++ b/libavcodec/iff.c @@ -180,6 +180,10 @@ static int cmap_read_palette(AVCodecContext *avctx, uint32_t *pal) pal[i] = 0xFF000000 | gray2rgb((i * 255) >> avctx->bits_per_coded_sample); } if (s->masking == MASK_HAS_MASK) { + if ((1 << avctx->bits_per_coded_sample) < count) { + avpriv_request_sample(avctx, "overlapping mask"); + return AVERROR_PATCHWELCOME; + } memcpy(pal + (1 << avctx->bits_per_coded_sample), pal, count * 4); for (i = 0; i < count; i++) pal[i] &= 0xFFFFFF; -- 2.39.2