RepoMirrors
/
ffmpeg
mirror of https://git.ffmpeg.org/ffmpeg.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Michael Niedermayer 2023-09-30 00:27:14 +02:00
parent 4743c9e87a
commit d384af5226
No known key found for this signature in database
GPG Key ID: B18E8928B3948D64
1 changed files with 10 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
libavformat/avidec.c
View File

@ -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;