[FFmpeg-devel] [PATCH 3/4] avformat/subtitles: Check nb_subs in ff_subtitles_queue_finalize()
Michael Niedermayer
michael at niedermayer.cc
Fri Oct 4 20:59:41 EEST 2019
Fixes: null pointer dereference
Fixes: 17828/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5645915116797952
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
libavformat/subtitles.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/libavformat/subtitles.c b/libavformat/subtitles.c
index 659c99d1cf..ded1b910c5 100644
--- a/libavformat/subtitles.c
+++ b/libavformat/subtitles.c
@@ -194,9 +194,10 @@ void ff_subtitles_queue_finalize(void *log_ctx, FFDemuxSubtitlesQueue *q)
{
int i;
- qsort(q->subs, q->nb_subs, sizeof(*q->subs),
- q->sort == SUB_SORT_TS_POS ? cmp_pkt_sub_ts_pos
- : cmp_pkt_sub_pos_ts);
+ if (q->nb_subs)
+ qsort(q->subs, q->nb_subs, sizeof(*q->subs),
+ q->sort == SUB_SORT_TS_POS ? cmp_pkt_sub_ts_pos
+ : cmp_pkt_sub_pos_ts);
for (i = 0; i < q->nb_subs; i++)
if (q->subs[i].duration < 0 && i < q->nb_subs - 1)
q->subs[i].duration = q->subs[i + 1].pts - q->subs[i].pts;
--
2.23.0
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