[FFmpeg-cvslog] avformat/nsvdec: Fix memleaks on errors while reading the header

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Mar 18 20:20:44 2020 +0100| [96c04694550999cc214cae8c4a16d2d7ac0958bc] | committer: Michael Niedermayer

avformat/nsvdec: Fix memleaks on errors while reading the header

Fixes: memleaks
Fixes: 21084/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5655975492321280

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=96c04694550999cc214cae8c4a16d2d7ac0958bc
---

 libavformat/nsvdec.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/libavformat/nsvdec.c b/libavformat/nsvdec.c
index 7aa1b605b0..b5d9313778 100644
--- a/libavformat/nsvdec.c
+++ b/libavformat/nsvdec.c
@@ -211,6 +211,7 @@ static const AVCodecTag nsv_codec_audio_tags[] = {
 
 //static int nsv_load_index(AVFormatContext *s);
 static int nsv_read_chunk(AVFormatContext *s, int fill_header);
+static int nsv_read_close(AVFormatContext *s);
 
 /* try to find something we recognize, and set the state accordingly */
 static int nsv_resync(AVFormatContext *s)
@@ -492,25 +493,32 @@ static int nsv_read_header(AVFormatContext *s)
     nsv->ahead[0].data = nsv->ahead[1].data = NULL;
 
     for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
-        if (nsv_resync(s) < 0)
-            return -1;
+        err = nsv_resync(s);
+        if (err < 0)
+            goto fail;
         if (nsv->state == NSV_FOUND_NSVF) {
             err = nsv_parse_NSVf_header(s);
             if (err < 0)
-                return err;
+                goto fail;
         }
             /* we need the first NSVs also... */
         if (nsv->state == NSV_FOUND_NSVS) {
             err = nsv_parse_NSVs_header(s);
             if (err < 0)
-                return err;
+                goto fail;
             break; /* we just want the first one */
         }
     }
-    if (s->nb_streams < 1) /* no luck so far */
-        return -1;
+    if (s->nb_streams < 1) { /* no luck so far */
+        err = AVERROR_INVALIDDATA;
+        goto fail;
+    }
+
     /* now read the first chunk, so we can attempt to decode more info */
     err = nsv_read_chunk(s, 1);
+fail:
+    if (err < 0)
+        nsv_read_close(s);
 
     av_log(s, AV_LOG_TRACE, "parsed header\n");
     return err;