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| author | Michael Niedermayer <michael@niedermayer.cc> | 2023-09-30 00:27:14 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2024-03-26 00:08:25 +0100 |
| commit | d384af52261ff01ee35c05d46303d617de5305bb (patch) | |
| tree | f8564d2d12e4d271f6960a23673f8386d1b3fde4 | |
| parent | 4743c9e87a629d6af53b508c6a36135590622c16 (diff) | |
| download | ffmpeg-d384af52261ff01ee35c05d46303d617de5305bb.tar.gz | |
avformat/avidec: support huge durations
Fixes: signed integer overflow: 109817402400 * 301990077 cannot be represented in type 'long long'
Fixes: 51896/clusterfuzz-testcase-minimized-ffmpeg_dem_AVI_fuzzer-6706191715139584
Fixes: 62276/clusterfuzz-testcase-minimized-ffmpeg_dem_AVI_fuzzer-6706191715139584
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavformat/avidec.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/libavformat/avidec.c b/libavformat/avidec.c index 985a9bf022..bfa5c02a20 100644 --- a/libavformat/avidec.c +++ b/libavformat/avidec.c @@ -27,6 +27,7 @@ #include "libavutil/avstring.h" #include "libavutil/opt.h" #include "libavutil/dict.h" +#include "libavutil/integer.h" #include "libavutil/internal.h" #include "libavutil/intreadwrite.h" #include "libavutil/mathematics.h" @@ -476,7 +477,7 @@ static int calculate_bitrate(AVFormatContext *s) AVStream *st = s->streams[i]; FFStream *const sti = ffstream(st); int64_t duration; - int64_t bitrate; + AVInteger bitrate_i, den_i, num_i; for (j = 0; j < sti->nb_index_entries; j++) len += sti->index_entries[j].size; @@ -484,9 +485,14 @@ static int calculate_bitrate(AVFormatContext *s) if (sti->nb_index_entries < 2 || st->codecpar->bit_rate > 0) continue; duration = sti->index_entries[j-1].timestamp - sti->index_entries[0].timestamp; - bitrate = av_rescale(8*len, st->time_base.den, duration * st->time_base.num); - if (bitrate > 0) { - st->codecpar->bit_rate = bitrate; + den_i = av_mul_i(av_int2i(duration), av_int2i(st->time_base.num)); + num_i = av_add_i(av_mul_i(av_int2i(8*len), av_int2i(st->time_base.den)), av_shr_i(den_i, 1)); + bitrate_i = av_div_i(num_i, den_i); + if (av_cmp_i(bitrate_i, av_int2i(INT64_MAX)) <= 0) { + int64_t bitrate = av_i2int(bitrate_i); + if (bitrate > 0) { + st->codecpar->bit_rate = bitrate; + } } } return 1; |