[FFmpeg-cvslog] avformat/nsvdec: Do not parse multiple NSVf

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Aug 16 12:23:20 2018 +0200| [78d4b6bd43fc266a2ee926f0555c8782246f9445] | committer: Michael Niedermayer

avformat/nsvdec: Do not parse multiple NSVf

The specification states "NSV files may contain a single file header. "
Fixes: out of array access
Fixes: nsv-asan-002f473f726a0dcbd3bd53e422c4fc40b3cf3421

Found-by: Paul Ch <paulcher at icloud.com>
Tested-by: Paul Ch <paulcher at icloud.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=78d4b6bd43fc266a2ee926f0555c8782246f9445
---

 libavformat/nsvdec.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libavformat/nsvdec.c b/libavformat/nsvdec.c
index d8ce656817..92f7d178f6 100644
--- a/libavformat/nsvdec.c
+++ b/libavformat/nsvdec.c
@@ -176,6 +176,7 @@ typedef struct NSVContext {
     int16_t avsync;
     AVRational framerate;
     uint32_t *nsvs_timestamps;
+    int nsvf;
 } NSVContext;
 
 static const AVCodecTag nsv_codec_video_tags[] = {
@@ -266,6 +267,12 @@ static int nsv_parse_NSVf_header(AVFormatContext *s)
 
     nsv->state = NSV_UNSYNC; /* in case we fail */
 
+    if (nsv->nsvf) {
+        av_log(s, AV_LOG_TRACE, "Multiple NSVf\n");
+        return 0;
+    }
+    nsv->nsvf = 1;
+
     size = avio_rl32(pb);
     if (size < 28)
         return -1;