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| author | Michael Niedermayer <michael@niedermayer.cc> | 2021-03-17 21:58:53 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2021-10-06 14:41:41 +0200 |
| commit | b5e7092c9cc603ca9312dea1f0eb2bd331784fc1 (patch) | |
| tree | bc9505a68b0d7feec3857c76754364c9cab49928 | |
| parent | c44458dcfaf97b3cf813cf9e97e4208d2751769c (diff) | |
| download | ffmpeg-b5e7092c9cc603ca9312dea1f0eb2bd331784fc1.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>
| -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) |