[FFmpeg-cvslog] avformat/libzmq: Check av_strstart()

[Michael Niedermayer]

ffmpeg | branch: release/5.1 | Michael Niedermayer <michael at niedermayer.cc> | Mon Jun  3 01:19:36 2024 +0200| [8dc091daee4532264c8c06e5a081d35b8892ba18] | committer: Michael Niedermayer

avformat/libzmq: Check av_strstart()

Fixes: CID1453457 Unchecked return value

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 0263b6a48caaff839e4c28df15b299b89c7da92d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8dc091daee4532264c8c06e5a081d35b8892ba18
---

 libavformat/libzmq.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavformat/libzmq.c b/libavformat/libzmq.c
index 04c72ac601..f4bb849e46 100644
--- a/libavformat/libzmq.c
+++ b/libavformat/libzmq.c
@@ -94,7 +94,10 @@ static int zmq_proto_open(URLContext *h, const char *uri, int flags)
         return AVERROR_EXTERNAL;
     }
 
-    av_strstart(uri, "zmq:", &uri);
+    if (av_strstart(uri, "zmq:", &uri)) {
+        av_log(h, AV_LOG_ERROR, "URL %s lacks prefix\n", uri);
+        return AVERROR(EINVAL);
+    }
 
     /*publish during write*/
     if (h->flags & AVIO_FLAG_WRITE) {