diff options
| author | Michael Niedermayer <michael@niedermayer.cc> | 2020-09-21 22:40:48 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2020-10-18 20:42:21 +0200 |
| commit | ee33fecb62c6dabcfdb9199d7a5b8575b758f1d9 (patch) | |
| tree | 2157e44cd9d1a7a3d7eacf500d6d3a0c730a1381 /libavcodec | |
| parent | 34df97b0886c728e1ae430a7de8b3dfd2f1a5744 (diff) | |
avcodec/mpeg12dec: Limit maximum A53 CC size
This is more than 10 times the size of the largest i found. And also alot more
than our encoder could handle (our encoder is limited to max 31)
Without any limit megabyte+ sized blocks can be reallocated millions of times.
Sadly the SCTE-20 spec does not seem to contain any hard limit directly, so this limit here
is arbitrary
Fixes: Timeout (25sec -> 152ms)
Fixes: 25714/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG2VIDEO_fuzzer-5713633336885248
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 'libavcodec')
| -rw-r--r-- | libavcodec/mpeg12dec.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c index 3be90d7f25..6d0e9fc7ed 100644 --- a/libavcodec/mpeg12dec.c +++ b/libavcodec/mpeg12dec.c @@ -50,6 +50,8 @@ #include "version.h" #include "xvmc_internal.h" +#define A53_MAX_CC_COUNT 2000 + typedef struct Mpeg1Context { MpegEncContext mpeg_enc_ctx; int mpeg_enc_ctx_allocated; /* true if decoding context allocated */ @@ -2240,7 +2242,7 @@ static int mpeg_decode_a53_cc(AVCodecContext *avctx, * UINT64_C(3)); int ret; - if (new_size > INT_MAX) + if (new_size > 3*A53_MAX_CC_COUNT) return AVERROR(EINVAL); ret = av_buffer_realloc(&s1->a53_buf_ref, new_size); @@ -2263,7 +2265,7 @@ static int mpeg_decode_a53_cc(AVCodecContext *avctx, int old_size = s1->a53_buf_ref ? s1->a53_buf_ref->size : 0; const uint64_t new_size = (old_size + cc_count * UINT64_C(3)); - if (new_size > INT_MAX) + if (new_size > 3*A53_MAX_CC_COUNT) return AVERROR(EINVAL); ret = av_buffer_realloc(&s1->a53_buf_ref, new_size); @@ -2333,7 +2335,7 @@ static int mpeg_decode_a53_cc(AVCodecContext *avctx, int old_size = s1->a53_buf_ref ? s1->a53_buf_ref->size : 0; const uint64_t new_size = (old_size + cc_count * UINT64_C(6)); - if (new_size > INT_MAX) + if (new_size > 3*A53_MAX_CC_COUNT) return AVERROR(EINVAL); ret = av_buffer_realloc(&s1->a53_buf_ref, new_size); |