From 461811e2b2e6a3a82c27d2a8aeec25a71dc91e9a Mon Sep 17 00:00:00 2001
From: Fabrice Bellet <fabrice@bellet.info>
Date: Tue, 23 May 2017 16:06:47 +0200
Subject: [PATCH] rtp: fix a double locking issue on the session

The session value used in fs_rtp_stream_add_substream_unlock(), taken
from the stream struct may be null, while the session value from
fs_rtp_session_new_recv_pad() is not. However these two function depend
on the same session value to properly lock and unlock it: the first
function will unlock the session previously locked by the second
function.
---
 gst/fsrtpconference/fs-rtp-session.c | 6 +++---
 gst/fsrtpconference/fs-rtp-stream.c  | 7 +++----
 gst/fsrtpconference/fs-rtp-stream.h  | 3 ++-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/gst/fsrtpconference/fs-rtp-session.c b/gst/fsrtpconference/fs-rtp-session.c
index a90dcfc..6f0101c 100644
--- a/gst/fsrtpconference/fs-rtp-session.c
+++ b/gst/fsrtpconference/fs-rtp-session.c
@@ -3287,7 +3287,7 @@ fs_rtp_session_new_recv_pad (FsRtpSession *session, GstPad *new_pad,
 
   if (stream)
   {
-    if (!fs_rtp_stream_add_substream_unlock (stream, substream, &error))
+    if (!fs_rtp_stream_add_substream_unlock (session, stream, substream, &error))
     {
       g_prefix_error (&error,
           "Could not add the output ghostpad to the new substream: ");
@@ -4360,7 +4360,7 @@ fs_rtp_session_associate_free_substreams (FsRtpSession *session,
         g_signal_handlers_disconnect_by_func (substream, "no-rtcp-timedout",
             session) > 0);
 
-    if (fs_rtp_stream_add_substream_unlock (stream, substream, &error))
+    if (fs_rtp_stream_add_substream_unlock (session, stream, substream, &error))
     {
       GST_DEBUG ("Associated SSRC %x in session %u", ssrc, session->id);
     }
@@ -4485,7 +4485,7 @@ _substream_no_rtcp_timedout_cb (FsRtpSubStream *substream,
 
   first_stream = g_list_first (session->priv->streams)->data;
   g_object_ref (first_stream);
-  if (!fs_rtp_stream_add_substream_unlock (first_stream, substream, &error))
+  if (!fs_rtp_stream_add_substream_unlock (session, first_stream, substream, &error))
   {
     g_prefix_error (&error,
         "Could not link the substream to a stream: ");
diff --git a/gst/fsrtpconference/fs-rtp-stream.c b/gst/fsrtpconference/fs-rtp-stream.c
index 1ef6b2e..52e1dec 100644
--- a/gst/fsrtpconference/fs-rtp-stream.c
+++ b/gst/fsrtpconference/fs-rtp-stream.c
@@ -1010,6 +1010,7 @@ _substream_unlinked (FsRtpSubStream *substream, gpointer user_data)
 
 /**
  * fs_rtp_stream_add_substream_unlock:
+ * @session: a #FsRtpSession
  * @stream: a #FsRtpStream
  * @substream: the #FsRtpSubStream to associate with this stream
  *
@@ -1021,12 +1022,12 @@ _substream_unlinked (FsRtpSubStream *substream, gpointer user_data)
  * Returns: TRUE on success, FALSE on failure
  */
 gboolean
-fs_rtp_stream_add_substream_unlock (FsRtpStream *stream,
+fs_rtp_stream_add_substream_unlock (FsRtpSession *session,
+    FsRtpStream *stream,
     FsRtpSubStream *substream,
     GError **error)
 {
   gboolean ret = TRUE;
-  FsRtpSession *session = fs_rtp_stream_get_session (stream, error);
 
   if (!session)
     return FALSE;
@@ -1055,8 +1056,6 @@ fs_rtp_stream_add_substream_unlock (FsRtpStream *stream,
   else
     FS_RTP_SESSION_UNLOCK (session);
 
-  g_object_unref (session);
-
   return ret;
 }
 
diff --git a/gst/fsrtpconference/fs-rtp-stream.h b/gst/fsrtpconference/fs-rtp-stream.h
index a4b3fb2..105dd9b 100644
--- a/gst/fsrtpconference/fs-rtp-stream.h
+++ b/gst/fsrtpconference/fs-rtp-stream.h
@@ -115,7 +115,8 @@ FsRtpStream *fs_rtp_stream_new (FsRtpSession *session,
     stream_decrypt_clear_locked_cb decrypt_clear_locked_cb,
     gpointer user_data_for_cb);
 
-gboolean fs_rtp_stream_add_substream_unlock (FsRtpStream *stream,
+gboolean fs_rtp_stream_add_substream_unlock (FsRtpSession *session,
+    FsRtpStream *stream,
     FsRtpSubStream *substream,
     GError **error);
 
-- 
2.9.4