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 4314fd1ebc8d3f761fd6e98322e0a1154f5b9bd8..1961b22178c11fb8c18268f1fe0c11f6f0642e5d 100644 (file)
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -202,8 +202,8 @@
 
 #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)                                               \
 
 /*%
@@ -432,7 +432,8 @@ const char *empty_zones[] = {
 };
 
 ISC_PLATFORM_NORETURN_PRE static void
-fatal(const char *msg, isc_result_t result) ISC_PLATFORM_NORETURN_POST;
+fatal(named_server_t *server,const char *msg, isc_result_t result)
+ISC_PLATFORM_NORETURN_POST;
 
 static void
 named_server_reload(isc_task_t *task, isc_event_t *event);
@@ -9718,7 +9719,7 @@ named_server_create(isc_mem_t *mctx, named_server_t **serverp) {
        named_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;
@@ -9927,7 +9928,15 @@ named_server_destroy(named_server_t **serverp) {
 }
 
 static void
-fatal(const char *msg, isc_result_t result) {
+fatal(named_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(named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
                      NAMED_LOGMODULE_SERVER, ISC_LOG_CRITICAL,
                      "%s: %s", msg, isc_result_totext(result));