From a31fc54c6c9b8e21ecb3b89f0cb1322d66826427 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Wed, 18 Mar 2020 20:20:44 +0100
Subject: [PATCH] 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@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 96c04694550999cc214cae8c4a16d2d7ac0958bc)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavformat/nsvdec.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/libavformat/nsvdec.c b/libavformat/nsvdec.c
index 9727aafcca..b427585eb4 100644
--- a/libavformat/nsvdec.c
+++ b/libavformat/nsvdec.c
@@ -212,6 +212,7 @@ 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);
 
 #define print_tag(str, tag, size)       \
     av_log(NULL, AV_LOG_TRACE, "%s: tag=%c%c%c%c\n", \
@@ -513,25 +514,32 @@ 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;