avcodec/cfhd: check peak.offset

Fixes: signed integer overflow: -2147483648 - 4 cannot be represented in type 'int'
Fixes: 26907/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-5746202330267648

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2020-11-08 00:08:35 +01:00
parent b0f8586ca9
commit 386faeda5f
1 changed files with 6 additions and 0 deletions

View File

@ -617,6 +617,12 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
s->peak.level = 0;
} else if (tag == -PeakLevel && s->peak.offset) {
s->peak.level = data;
if (s->peak.offset < 4 - bytestream2_tell(&s->peak.base) ||
s->peak.offset > 4 + bytestream2_get_bytes_left(&s->peak.base)
) {
ret = AVERROR_INVALIDDATA;
goto end;
}
bytestream2_seek(&s->peak.base, s->peak.offset - 4, SEEK_CUR);
} else
av_log(avctx, AV_LOG_DEBUG, "Unknown tag %i data %x\n", tag, data);