From d96b6a4a8f97fe2bead4099c3ad9dbd16276ae40 Mon Sep 17 00:00:00 2001
From: Andrey Volk <andywolk@gmail.com>
Date: Sat, 23 Jul 2022 22:07:40 +0300
Subject: [PATCH] [Core] Fix possible race condition between locking a session
and reading it's flags in switch_core_session_read_lock() and
switch_core_session_read_lock_hangup().
---
src/switch_core_rwlock.c | 44 +++++++++++++++++++++-------------------
1 file changed, 23 insertions(+), 21 deletions(-)
diff --git a/src/switch_core_rwlock.c b/src/switch_core_rwlock.c
index 61c9ca45b9..69e188ed79 100644
--- a/src/switch_core_rwlock.c
+++ b/src/switch_core_rwlock.c
@@ -85,9 +85,9 @@ SWITCH_DECLARE(switch_status_t) switch_core_session_read_lock(switch_core_sessio
switch_status_t status = SWITCH_STATUS_FALSE;
if (session->rwlock) {
- if (switch_test_flag(session, SSF_DESTROYED) || switch_channel_down_nosig(session->channel)) {
- status = SWITCH_STATUS_FALSE;
- if (switch_thread_rwlock_tryrdlock(session->rwlock) == SWITCH_STATUS_SUCCESS) {
+ if ((status = switch_thread_rwlock_tryrdlock(session->rwlock)) == SWITCH_STATUS_SUCCESS) {
+ if (switch_test_flag(session, SSF_DESTROYED) || switch_channel_down_nosig(session->channel)) {
+ status = SWITCH_STATUS_FALSE;
if (switch_channel_test_flag(session->channel, CF_THREAD_SLEEPING)) {
#ifdef SWITCH_DEBUG_RWLOCKS
switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Ping thread\n",
@@ -95,18 +95,18 @@ SWITCH_DECLARE(switch_status_t) switch_core_session_read_lock(switch_core_sessio
#endif
switch_core_session_wake_session_thread(session);
}
+
+#ifdef SWITCH_DEBUG_RWLOCKS
+ switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Read lock FAIL\n",
+ switch_core_session_get_uuid(session), switch_channel_get_name(session->channel));
+#endif
switch_thread_rwlock_unlock(session->rwlock);
+ } else {
+#ifdef SWITCH_DEBUG_RWLOCKS
+ switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Read lock ACQUIRED\n",
+ switch_core_session_get_uuid(session), switch_channel_get_name(session->channel));
+#endif
}
-#ifdef SWITCH_DEBUG_RWLOCKS
- switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Read lock FAIL\n",
- switch_core_session_get_uuid(session), switch_channel_get_name(session->channel));
-#endif
- } else {
- status = (switch_status_t) switch_thread_rwlock_tryrdlock(session->rwlock);
-#ifdef SWITCH_DEBUG_RWLOCKS
- switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Read lock ACQUIRED\n",
- switch_core_session_get_uuid(session), switch_channel_get_name(session->channel));
-#endif
}
}
@@ -123,18 +123,20 @@ SWITCH_DECLARE(switch_status_t) switch_core_session_read_lock_hangup(switch_core
switch_status_t status = SWITCH_STATUS_FALSE;
if (session->rwlock) {
- if (switch_test_flag(session, SSF_DESTROYED) || switch_channel_get_state(session->channel) >= CS_DESTROY) {
- status = SWITCH_STATUS_FALSE;
+ if ((status = switch_thread_rwlock_tryrdlock(session->rwlock)) == SWITCH_STATUS_SUCCESS) {
+ if (switch_test_flag(session, SSF_DESTROYED) || switch_channel_get_state(session->channel) >= CS_DESTROY) {
+ status = SWITCH_STATUS_FALSE;
#ifdef SWITCH_DEBUG_RWLOCKS
- switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Read lock FAIL\n",
- switch_core_session_get_uuid(session), switch_channel_get_name(session->channel));
+ switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Read lock FAIL\n",
+ switch_core_session_get_uuid(session), switch_channel_get_name(session->channel));
#endif
- } else {
- status = (switch_status_t) switch_thread_rwlock_tryrdlock(session->rwlock);
+ switch_thread_rwlock_unlock(session->rwlock);
+ } else {
#ifdef SWITCH_DEBUG_RWLOCKS
- switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Read lock ACQUIRED\n",
- switch_core_session_get_uuid(session), switch_channel_get_name(session->channel));
+ switch_log_printf(SWITCH_CHANNEL_ID_LOG, file, func, line, switch_core_session_get_uuid(session), SWITCH_LOG_ERROR, "%s %s Read lock ACQUIRED\n",
+ switch_core_session_get_uuid(session), switch_channel_get_name(session->channel));
#endif
+ }
}
}