diff --git a/channels/chan_pjsip.c b/channels/chan_pjsip.c index 370075d2b7..22f834d376 100644 --- a/channels/chan_pjsip.c +++ b/channels/chan_pjsip.c @@ -269,6 +269,9 @@ static int direct_media_mitigate_glare(struct ast_sip_session *session) return 0; } +/*! + * \pre chan is locked + */ static int check_for_rtp_changes(struct ast_channel *chan, struct ast_rtp_instance *rtp, struct ast_sip_session_media *media, int rtcp_fd) { @@ -338,6 +341,11 @@ static int send_direct_media_request(void *data) int changed = 0; int res = 0; + /* The channel needs to be locked when checking for RTP changes. + * Otherwise, we could end up destroying an underlying RTCP structure + * at the same time that the channel thread is attempting to read RTCP + */ + ast_channel_lock(cdata->chan); if (pvt->media[SIP_MEDIA_AUDIO]) { changed |= check_for_rtp_changes( cdata->chan, cdata->rtp, pvt->media[SIP_MEDIA_AUDIO], 1); @@ -346,6 +354,7 @@ static int send_direct_media_request(void *data) changed |= check_for_rtp_changes( cdata->chan, cdata->vrtp, pvt->media[SIP_MEDIA_VIDEO], 3); } + ast_channel_unlock(cdata->chan); if (direct_media_mitigate_glare(cdata->session)) { ast_debug(4, "Disregarding setting RTP on %s: mitigating re-INVITE glare\n", ast_channel_name(cdata->chan));