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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-06-27 00:02:31 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-07-08 09:50:00 +0200 |
| commit | e69106e70c89ed4864f504891d28886df6b15441 (patch) | |
| tree | f37bb24e90768398d3dcfbd8887e96271345ad0d /libavformat | |
| parent | 2bbea155bf7c6ce6d5ae53cc41e44798cad2f39c (diff) | |
| download | ffmpeg-e69106e70c89ed4864f504891d28886df6b15441.tar.gz | |
avformat/vividas: Check for input length in get_v()
Fixes: out of array read
Fixes: 15286/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5658245101780992
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavformat')
| -rw-r--r-- | libavformat/vividas.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/libavformat/vividas.c b/libavformat/vividas.c index 753328245d..350c7aa70a 100644 --- a/libavformat/vividas.c +++ b/libavformat/vividas.c @@ -178,12 +178,13 @@ static void decode_block(uint8_t *src, uint8_t *dest, unsigned size, } } -static uint32_t get_v(uint8_t *p) +static uint32_t get_v(uint8_t *p, int len) { uint32_t v = 0; + const uint8_t *end = p + len; do { - if (v >= UINT_MAX / 128 - *p) + if (p >= end || v >= UINT_MAX / 128 - *p) return v; v <<= 7; v += *p & 0x7f; @@ -204,7 +205,7 @@ static uint8_t *read_vblock(AVIOContext *src, uint32_t *size, decode_block(tmp, tmp, 4, key, k2, align); - n = get_v(tmp); + n = get_v(tmp, 4); if (n < 4) return NULL; @@ -241,13 +242,13 @@ static uint8_t *read_sb_block(AVIOContext *src, unsigned *size, k2 = *key; decode_block(ibuf, sbuf, 8, *key, &k2, 0); - n = get_v(sbuf+2); + n = get_v(sbuf+2, 6); if (sbuf[0] != 'S' || sbuf[1] != 'B' || (expected_size>0 && n != expected_size)) { uint32_t tmpkey = recover_key(ibuf, expected_size); k2 = tmpkey; decode_block(ibuf, sbuf, 8, tmpkey, &k2, 0); - n = get_v(sbuf+2); + n = get_v(sbuf+2, 6); if (sbuf[0] != 'S' || sbuf[1] != 'B' || expected_size != n) return NULL; *key = tmpkey; |