avformat/wavdec: Refuse to read chunks bigger than the filesize in w64_read_header()

Fixes: OOM
Fixes: 26414/clusterfuzz-testcase-minimized-ffmpeg_dem_FWSE_fuzzer-5070632544632832
Fixes: 26475/clusterfuzz-testcase-minimized-ffmpeg_dem_W64_fuzzer-5770207722995712

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 2020-10-17 23:50:57 +02:00
parent c79d8a6851
commit 7b2244565a

View File

@ -902,6 +902,7 @@ static int w64_read_header(AVFormatContext *s)
} else if (!memcmp(guid, ff_w64_guid_summarylist, 16)) {
int64_t start, end, cur;
uint32_t count, chunk_size, i;
int64_t filesize = avio_size(s->pb);
start = avio_tell(pb);
end = start + FFALIGN(size, INT64_C(8)) - 24;
@ -916,7 +917,7 @@ static int w64_read_header(AVFormatContext *s)
chunk_key[4] = 0;
avio_read(pb, chunk_key, 4);
chunk_size = avio_rl32(pb);
if (chunk_size == UINT32_MAX)
if (chunk_size == UINT32_MAX || (filesize >= 0 && chunk_size > filesize))
return AVERROR_INVALIDDATA;
value = av_mallocz(chunk_size + 1);