[Switching to Thread 0x7ffff3e68700 (LWP 29096)]
0x00007ffff7721225 in concatb (mp=0x7fffec0084e0, newm=0x0)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/oRTP/src/str_utils.c:317
317             while(newm->b_cont!=NULL) newm=newm->b_cont;
(gdb) bt
#0  0x00007ffff7721225 in concatb (mp=0x7fffec0084e0, newm=0x0)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/oRTP/src/str_utils.c:317
#1  0x00007ffff77105db in append_sdes (session=0x614c20, m=0x7fffec0084e0, full=1 '\001')
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/oRTP/src/rtcp.c:397
#2  0x00007ffff77108a4 in rtp_session_create_and_send_rtcp_packet (session=0x614c20, full=1 '\001')
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/oRTP/src/rtcp.c:460
#3  0x00007ffff7710df2 in rtp_session_send_regular_rtcp_packet_and_reschedule (session=0x614c20, tc=81144871)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/oRTP/src/rtcp.c:569
#4  0x00007ffff7710fbf in rtp_session_run_rtcp_send_scheduler (session=0x614c20)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/oRTP/src/rtcp.c:604
#5  0x00007ffff7711028 in rtp_session_rtcp_process_recv (session=0x614c20)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/oRTP/src/rtcp.c:620
#6  0x00007ffff77184e1 in rtp_session_recvm_with_ts (session=0x614c20, user_ts=2934900)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/oRTP/src/rtpsession.c:1258
#7  0x00007ffff795b1a3 in receiver_process (f=0x6172a0)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/mediastreamer2/src/otherfilters/msrtp.c:706
#8  0x00007ffff7bcad99 in ms_filter_process (f=0x6172a0)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/mediastreamer2/src/base/msfilter.c:207
#9  0x00007ffff7bcd08a in call_process (f=0x6172a0)
    at /home/dev/mediastreamer2-linphone/desktop/linphone-desktop/submodules/linphone/mediastreamer2/src/base/msticker.c:225
#10 0x00007ffff7bcd14c in run_graph (f=0x6172a0, s=0x618e70, unschedulable=0x7ffff3e67e78, force_schedule=0 '\000')