[Asterisk-code-review] chan sip: Fix segfault during module unload (asterisk[master])

[Michael Kuron]

Michael Kuron has uploaded a new change for review. ( https://gerrit.asterisk.org/4496 )

Change subject: chan_sip: Fix segfault during module unload
......................................................................

chan_sip: Fix segfault during module unload

If a TCP/TLS connection was pending (not accepted and not timed out) during
unload of chan_sip, Asterisk would segfault when trying to send a signal to
a thread whose thread ID hadn't been recorded yet. This commit fixes that by
recording the thread ID before calling the blocking connect() syscall.
This was a regression introduced by 776a14386a55b5425c7e9617eff8af8b45427144.

The above wasn't enough to fix the segfault, which was now delayed to the
point where connect() timed out. Therefore, it was necessary to also remove
the SA_RESTART flag from the SIGURG sigaction so that pthread_kill() could be
used to interruput the connect() syscall.
This was a regression introduced by 5d313f51b982a18f7321adcf7c7a4e822d8b2714.

ASTERISK-26586 #close

Change-Id: I76fd9d47d56e4264e2629bce8ec15fecba673e7b
---
M channels/chan_sip.c
M main/asterisk.c
2 files changed, 8 insertions(+), 4 deletions(-)


  git pull ssh://gerrit.asterisk.org:29418/asterisk refs/changes/96/4496/1

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 870b53e..16d84af 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -2957,6 +2957,7 @@
 		if (!(me = sip_threadinfo_create(tcptls_session, ast_iostream_get_ssl(tcptls_session->stream) ? AST_TRANSPORT_TLS : AST_TRANSPORT_TCP))) {
 			goto cleanup;
 		}
+		me->threadid = pthread_self();
 		ao2_t_ref(me, +1, "Adding threadinfo ref for tcp_helper_thread");
 	} else {
 		struct sip_threadinfo tmp = {
@@ -2964,8 +2965,13 @@
 		};
 
 		if ((!(ca = tcptls_session->parent)) ||
-			(!(me = ao2_t_find(threadt, &tmp, OBJ_POINTER, "ao2_find, getting sip_threadinfo in tcp helper thread"))) ||
-			(!(tcptls_session = ast_tcptls_client_start(tcptls_session)))) {
+			(!(me = ao2_t_find(threadt, &tmp, OBJ_POINTER, "ao2_find, getting sip_threadinfo in tcp helper thread")))) {
+			goto cleanup;
+		}
+
+		me->threadid = pthread_self();
+
+		if (!(tcptls_session = ast_tcptls_client_start(tcptls_session))) {
 			goto cleanup;
 		}
 	}
@@ -2976,7 +2982,6 @@
 		goto cleanup;
 	}
 
-	me->threadid = pthread_self();
 	ast_debug(2, "Starting thread for %s server\n", ast_iostream_get_ssl(tcptls_session->stream) ? "TLS" : "TCP");
 
 	/* set up pollfd to watch for reads on both the socket and the alert_pipe */
diff --git a/main/asterisk.c b/main/asterisk.c
index 4a6567f..98ae881 100644
--- a/main/asterisk.c
+++ b/main/asterisk.c
@@ -1669,7 +1669,6 @@
 
 static struct sigaction urg_handler = {
 	.sa_handler = _urg_handler,
-	.sa_flags = SA_RESTART,
 };
 
 static void _hup_handler(int num)

-- 
To view, visit https://gerrit.asterisk.org/4496
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I76fd9d47d56e4264e2629bce8ec15fecba673e7b
Gerrit-PatchSet: 1
Gerrit-Project: asterisk
Gerrit-Branch: master
Gerrit-Owner: Michael Kuron <m.kuron at gmx.de>