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author | Michael Niedermayer <michael@niedermayer.cc> | 2019-11-15 23:00:51 +0100 |
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committer | Michael Niedermayer <michael@niedermayer.cc> | 2020-07-02 19:55:08 +0200 |
commit | 57c602ab246a5ed2fb14d0bd0180c76a1984d494 (patch) | |
tree | cf2282aea8ffb4cf1973d6b162b73b0a8003b8ad | |
parent | bc73f923e23d7e0ebcc64dac11b1309d3be3ed82 (diff) | |
download | ffmpeg-57c602ab246a5ed2fb14d0bd0180c76a1984d494.tar.gz |
avformat/rmdec: Initialize and sanity check offset in ivr_read_header()
Fixes: signed integer overflow: -9223372036854775808 - 17 cannot be represented in type 'long'
Fixes: 18768/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5674385247830016
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 7e665e4a81e2e96eb45138a1dfa38617de2631a4)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
-rw-r--r-- | libavformat/rmdec.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c index f3fa550c63..9db163d392 100644 --- a/libavformat/rmdec.c +++ b/libavformat/rmdec.c @@ -1175,7 +1175,7 @@ static int ivr_read_header(AVFormatContext *s) uint8_t key[256], val[256]; AVIOContext *pb = s->pb; AVStream *st; - int64_t pos, offset, temp; + int64_t pos, offset=0, temp; pos = avio_tell(pb); tag = avio_rl32(pb); @@ -1192,6 +1192,8 @@ static int ivr_read_header(AVFormatContext *s) offset = temp; temp = avio_rb64(pb); } + if (offset <= 0) + return AVERROR_INVALIDDATA; avio_skip(pb, offset - avio_tell(pb)); if (avio_r8(pb) != 1) return AVERROR_INVALIDDATA; |