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author | Michael Niedermayer <michael@niedermayer.cc> | 2021-04-24 17:42:19 +0200 |
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committer | Michael Niedermayer <michael@niedermayer.cc> | 2021-10-06 14:41:41 +0200 |
commit | ed9fe15b4928f4f0358e978b9c315f590bc909e5 (patch) | |
tree | 42f9fc7dc5296bfd25e580e1e3018237ec25b5f6 | |
parent | 433e72f7e579a065de1d1811d9e2be4faec99b5f (diff) | |
download | ffmpeg-ed9fe15b4928f4f0358e978b9c315f590bc909e5.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>
(cherry picked from commit 8ef25d118246bf443900033fb3588dba628d11b0)
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 88c55e3d22..95813df748 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; |