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| author | Michael Niedermayer <michael@niedermayer.cc> | 2021-04-24 17:42:19 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2021-06-18 18:58:25 +0200 |
| commit | 8ef25d118246bf443900033fb3588dba628d11b0 (patch) | |
| tree | fe9bbc1142870ba005ecc50d4ad8f503481330da | |
| parent | ff05326081922059314b8927cf9bbc9c7e73458f (diff) | |
| download | ffmpeg-8ef25d118246bf443900033fb3588dba628d11b0.tar.gz | |
avformat/mpc8: Check for position overflow in mpc8_handle_chunk()
Fixes: signed integer overflow: 15 + 9223372036854775796 cannot be represented in type 'long'
Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_MPC8_fuzzer-6723520756318208
Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_MPC8_fuzzer-6739833034768384
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavformat/mpc8.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/libavformat/mpc8.c b/libavformat/mpc8.c index 5498ce940d..df5d345f85 100644 --- a/libavformat/mpc8.c +++ b/libavformat/mpc8.c @@ -205,8 +205,11 @@ static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, in switch(tag){ case TAG_SEEKTBLOFF: - pos = avio_tell(pb) + size; + pos = avio_tell(pb); off = ffio_read_varlen(pb); + if (pos > INT64_MAX - size || off < 0 || off > INT64_MAX - chunk_pos) + return; + pos += size; mpc8_parse_seektable(s, chunk_pos + off); avio_seek(pb, pos, SEEK_SET); break; |