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 <michael@niedermayer.cc>
(cherry picked from commit dfa5d1a366)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-08-21 23:22:39 +02:00
parent 6bfec5efc4
commit 08e46a341a

View File

@ -171,6 +171,10 @@ 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;