[FFmpeg-devel] [PATCH 1/7] wav: fix potential crash in case of 'fmt ' tag not found

[Clément Bœsch]

---
 libavformat/wav.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/libavformat/wav.c b/libavformat/wav.c
index 1ae9413..0d06fc3 100644
--- a/libavformat/wav.c
+++ b/libavformat/wav.c
@@ -387,7 +387,7 @@ static int wav_read_header(AVFormatContext *s,
     int rf64;
     unsigned int tag;
     AVIOContext *pb = s->pb;
-    AVStream *st;
+    AVStream *st = NULL;
     WAVContext *wav = s->priv_data;
     int ret, got_fmt = 0;
     int64_t next_tag_ofs, data_ofs = -1;
@@ -484,10 +484,14 @@ break_loop:
 
     avio_seek(pb, data_ofs, SEEK_SET);
 
+    if (!st) {
+        av_log(s, AV_LOG_WARNING, "no 'fmt ' tag found\n");
+    } else {
     if (!sample_count && st->codec->channels && av_get_bits_per_sample(st->codec->codec_id))
         sample_count = (data_size<<3) / (st->codec->channels * (uint64_t)av_get_bits_per_sample(st->codec->codec_id));
     if (sample_count)
         st->duration = sample_count;
+    }
 
     ff_metadata_conv_ctx(s, NULL, wav_metadata_conv);
 
-- 
1.7.6.1