Request exclusive access when crashing via fatal()

When loading the configuration fails, there might be already other tasks
running and calling OpenSSL library functions.  The OpenSSL on_exit
handler is called when exiting the main process and there's a timing
race between the on_exit function that destroys OpenSSL allocated
resources (threads, locks, ...) and other tasks accessing the very same
resources leading to a crash in the system threading library. Therefore,
the fatal() function needs to request exlusive access to the task
manager to finish the already running tasks and exit only when no other
tasks are running.

(cherry picked from commit 952d7fde63dbe68f1a2955688ea06edf9eacc9e2)

diff --git a/bin/named/server.c b/bin/named/server.c
index 8dae079b6bc38b28a4ee0d81d10ecec380db8e8b..0e7b3b083e253582d2d9106c95202d47417100b0 100644 (file)
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -199,8 +199,8 @@
 
 #define CHECKFATAL(op, msg) \
        do { result = (op);                                       \
-              if (result != ISC_R_SUCCESS)                       \
-                       fatal(msg, result);                       \
+               if (result != ISC_R_SUCCESS)                      \
+                       fatal(server, msg, result);               \
        } while (0)                                               \
 
 /*%
@@ -429,7 +429,8 @@ const char *empty_zones[] = {
 };
 
 ISC_PLATFORM_NORETURN_PRE static void
-fatal(const char *msg, isc_result_t result) ISC_PLATFORM_NORETURN_POST;
+fatal(ns_server_t *server,const char *msg, isc_result_t result)
+ISC_PLATFORM_NORETURN_POST;
 
 static void
 ns_server_reload(isc_task_t *task, isc_event_t *event);
@@ -8983,7 +8984,7 @@ ns_server_create(isc_mem_t *mctx, ns_server_t **serverp) {
        ns_server_t *server = isc_mem_get(mctx, sizeof(*server));
 
        if (server == NULL)
-               fatal("allocating server object", ISC_R_NOMEMORY);
+               fatal(server, "allocating server object", ISC_R_NOMEMORY);
 
        server->mctx = mctx;
        server->task = NULL;
@@ -9267,7 +9268,15 @@ ns_server_destroy(ns_server_t **serverp) {
 }
 
 static void
-fatal(const char *msg, isc_result_t result) {
+fatal(ns_server_t *server, const char *msg, isc_result_t result) {
+       if (server != NULL) {
+               /*
+                * Prevent races between the OpenSSL on_exit registered
+                * function and any other OpenSSL calls from other tasks
+                * by requesting exclusive access to the task manager.
+                */
+               (void)isc_task_beginexclusive(server->task);
+       }
        isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL, NS_LOGMODULE_SERVER,
                      ISC_LOG_CRITICAL, "%s: %s", msg,
                      isc_result_totext(result));