avformat/mccdec: Initialize and check rate.den

Fixes: Assertion c > 0 failed at libavutil/mathematics.c:61
Fixes: use-of-uninitialized-value
Fixes: 42537627/clusterfuzz-testcase-minimized-fuzzer_protocol_memory-5939605805793280

Found-by: ossfuzz
Reported-by: Kacper Michajlow
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2024-11-03 20:18:36 +01:00
parent beca13a42e
commit bf8e43083f
No known key found for this signature in database
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@ -93,7 +93,7 @@ static int mcc_read_header(AVFormatContext *s)
{
MCCContext *mcc = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
AVRational rate;
AVRational rate = {0};
int64_t ts, pos;
uint8_t out[4096];
char line[4096];
@ -139,7 +139,7 @@ static int mcc_read_header(AVFormatContext *s)
continue;
}
if (av_sscanf(line, "%d:%d:%d:%d", &hh, &mm, &ss, &fs) != 4)
if (av_sscanf(line, "%d:%d:%d:%d", &hh, &mm, &ss, &fs) != 4 || rate.den <= 0)
continue;
ts = av_sat_add64(av_rescale(hh * 3600LL + mm * 60LL + ss, rate.num, rate.den), fs);