From 8f4819ce01584e0858fdc312aa8a17c55e350a92 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Storsj=C3=B6?= Date: Thu, 23 Jan 2025 12:53:10 +0200 Subject: [PATCH] rtmpproto: Avoid rare crashes in the fail: codepath in rtmp_open MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When running the cleanup in rtmp_close on failures in rtmp_open, we can in rare cases end up using rt->playpath, assuming that it is still set. The crash could happen if we hit the fail codepath in rtmp_open while publishing (rt->is_input == 0) with rt->state set to a value > STATE_FCPUBLISH. This would normally not happen while publishing; either we have an error (and rt->state <= STATE_FCPUBLISH) or we reach rt->state = STATE_PUBLISHING, and then we also return successfully from rtmp_open. The unexpected combination of states could happen if the server responds with e.g. "NetStream.Play.Stop" while expecting "NetStream.Publish.Start"; this sets rt->state to STATE_STOPPED, which also fulfills the condition "> STATE_FCPUBLISH". We don't need to free the rt->playpath/tcurl/flashver strings here; they're handled via AVOption, and thus are freed automatically when the protocol instance is freed (that's why they aren't freed manually within the rtmp_close function either). We also don't need to free the AVDictionary with options; it's owned by the caller. A smaller fix would be to just call rtmp_close before freeing the strings and dictionary, but as we don't need to free them at all, let's remove that redundant code. Signed-off-by: Martin Storsjö --- libavformat/rtmpproto.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/libavformat/rtmpproto.c b/libavformat/rtmpproto.c index a34020b092..4095ae9421 100644 --- a/libavformat/rtmpproto.c +++ b/libavformat/rtmpproto.c @@ -2925,10 +2925,6 @@ reconnect: return 0; fail: - av_freep(&rt->playpath); - av_freep(&rt->tcurl); - av_freep(&rt->flashver); - av_dict_free(opts); rtmp_close(s); return ret; }