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| author | Michael Niedermayer <michael@niedermayer.cc> | 2021-03-17 21:58:53 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2021-04-01 11:38:44 +0200 |
| commit | 807b703a48a7859098709916a0e438e3eec3bd7c (patch) | |
| tree | f7641d619479228679bf12ed4fcfc80e05dd0d5e /libavformat | |
| parent | 5978b8bd9ce1680bbe412815d8a40ca2089177ab (diff) | |
| download | ffmpeg-807b703a48a7859098709916a0e438e3eec3bd7c.tar.gz | |
avformat/mpc8: check for size overflow in mpc8_get_chunk_header()
Fixes: signed integer overflow: -9223372036854775760 - 50 cannot be represented in type 'long'
Fixes: 31673/clusterfuzz-testcase-minimized-ffmpeg_dem_MPC8_fuzzer-580134751869337
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 6cc65d3d6760cfb08c5a9e57d4306d88428e18d0)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavformat')
| -rw-r--r-- | libavformat/mpc8.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/libavformat/mpc8.c b/libavformat/mpc8.c index f33323a599..88c55e3d22 100644 --- a/libavformat/mpc8.c +++ b/libavformat/mpc8.c @@ -127,7 +127,11 @@ static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size) pos = avio_tell(pb); *tag = avio_rl16(pb); *size = ffio_read_varlen(pb); - *size -= avio_tell(pb) - pos; + pos -= avio_tell(pb); + if (av_sat_add64(*size, pos) != (uint64_t)*size + pos) { + *size = -1; + } else + *size += pos; } static void mpc8_parse_seektable(AVFormatContext *s, int64_t off) |