avcodec/decode: Consider discarded samples in max_samples

Fixes: Timeout (several minutes -> 3 sec)
Fixes: 25246/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALS_fuzzer-5943400661254144

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 2020-09-25 23:17:13 +02:00
parent c0c6b68ddb
commit cc072f7353
1 changed files with 9 additions and 2 deletions

View File

@ -318,7 +318,7 @@ static int64_t guess_correct_pts(AVCodecContext *ctx,
* returning any output, so this function needs to be called in a loop until it
* returns EAGAIN.
**/
static inline int decode_simple_internal(AVCodecContext *avctx, AVFrame *frame)
static inline int decode_simple_internal(AVCodecContext *avctx, AVFrame *frame, int64_t *discarded_samples)
{
AVCodecInternal *avci = avctx->internal;
DecodeSimpleContext *ds = &avci->ds;
@ -411,12 +411,14 @@ static inline int decode_simple_internal(AVCodecContext *avctx, AVFrame *frame)
!(avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL)) {
avci->skip_samples = FFMAX(0, avci->skip_samples - frame->nb_samples);
got_frame = 0;
*discarded_samples += frame->nb_samples;
}
if (avci->skip_samples > 0 && got_frame &&
!(avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL)) {
if(frame->nb_samples <= avci->skip_samples){
got_frame = 0;
*discarded_samples += frame->nb_samples;
avci->skip_samples -= frame->nb_samples;
av_log(avctx, AV_LOG_DEBUG, "skip whole frame, skip left: %d\n",
avci->skip_samples);
@ -444,6 +446,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
}
av_log(avctx, AV_LOG_DEBUG, "skip %d/%d samples\n",
avci->skip_samples, frame->nb_samples);
*discarded_samples += avci->skip_samples;
frame->nb_samples -= avci->skip_samples;
avci->skip_samples = 0;
}
@ -452,6 +455,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
if (discard_padding > 0 && discard_padding <= frame->nb_samples && got_frame &&
!(avctx->flags2 & AV_CODEC_FLAG2_SKIP_MANUAL)) {
if (discard_padding == frame->nb_samples) {
*discarded_samples += frame->nb_samples;
got_frame = 0;
} else {
if(avctx->pkt_timebase.num && avctx->sample_rate) {
@ -544,9 +548,12 @@ FF_ENABLE_DEPRECATION_WARNINGS
static int decode_simple_receive_frame(AVCodecContext *avctx, AVFrame *frame)
{
int ret;
int64_t discarded_samples = 0;
while (!frame->buf[0]) {
ret = decode_simple_internal(avctx, frame);
if (discarded_samples > avctx->max_samples)
return AVERROR(EAGAIN);
ret = decode_simple_internal(avctx, frame, &discarded_samples);
if (ret < 0)
return ret;
}