avformat/mov: do not set sign bit for chunk_offsets

Fixes: signed integer overflow: 2314885530818453536 - -7412889664301817824 cannot be represented in type 'long'
Fixes: 64296/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6304027146846208

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 2023-12-15 22:37:49 +01:00
parent c72a20f01a
commit cfc0a68d4d
No known key found for this signature in database
GPG Key ID: B18E8928B3948D64

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@ -2242,8 +2242,13 @@ static int mov_read_stco(MOVContext *c, AVIOContext *pb, MOVAtom atom)
for (i = 0; i < entries && !pb->eof_reached; i++)
sc->chunk_offsets[i] = avio_rb32(pb);
else if (atom.type == MKTAG('c','o','6','4'))
for (i = 0; i < entries && !pb->eof_reached; i++)
for (i = 0; i < entries && !pb->eof_reached; i++) {
sc->chunk_offsets[i] = avio_rb64(pb);
if (sc->chunk_offsets[i] < 0) {
av_log(c->fc, AV_LOG_WARNING, "Impossible chunk_offset\n");
sc->chunk_offsets[i] = 0;
}
}
else
return AVERROR_INVALIDDATA;