avformat/rmdec: Make expected_len 64bit

Fixes: signed integer overflow: 1347551268 * 14 cannot be represented in type 'int'
Fixes: 26458/clusterfuzz-testcase-minimized-ffmpeg_dem_RM_fuzzer-5655364324032512

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 2020-10-20 21:32:59 +02:00
parent b23a619c13
commit 728330462c

View File

@ -703,17 +703,19 @@ static int rm_sync(AVFormatContext *s, int64_t *timestamp, int *flags, int *stre
state= (state<<8) + avio_r8(pb);
if(state == MKBETAG('I', 'N', 'D', 'X')){
int n_pkts, expected_len;
int n_pkts;
int64_t expected_len;
len = avio_rb32(pb);
avio_skip(pb, 2);
n_pkts = avio_rb32(pb);
expected_len = 20 + n_pkts * 14;
if (len == 20)
expected_len = 20 + n_pkts * 14LL;
if (len == 20 && expected_len <= INT_MAX)
/* some files don't add index entries to chunk size... */
len = expected_len;
else if (len != expected_len)
av_log(s, AV_LOG_WARNING,
"Index size %d (%d pkts) is wrong, should be %d.\n",
"Index size %d (%d pkts) is wrong, should be %"PRId64".\n",
len, n_pkts, expected_len);
len -= 14; // we already read part of the index header
if(len<0)