Address lock-order-inversion

Obtain references to view->redirect and view->managed_keys then
release view->lock so dns_zone_setviewcommit and dns_zone_setviewrevert
can obtain the view->lock while holding zone->lock.

WARNING: ThreadSanitizer: lock-order-inversion (potential deadlock) (pid=9132)
  Cycle in lock order graph: M987831431424375936 (0x000000000000) => M1012319771577875480 (0x000000000000) => M987831431424375936

  Mutex M1012319771577875480 acquired here while holding mutex M987831431424375936 in thread T2:
    #0 pthread_mutex_lock <null> (named+0x4642a6)
    #1 dns_zone_setviewcommit /builds/isc-projects/bind9/lib/dns/zone.c:1571:2 (libdns.so.1110+0x1d74eb)
    #2 dns_view_setviewcommit /builds/isc-projects/bind9/lib/dns/view.c:2388:3 (libdns.so.1110+0x1cfe29)
    #3 load_configuration /builds/isc-projects/bind9/bin/named/./server.c:8188:3 (named+0x51eadd)
    #4 loadconfig /builds/isc-projects/bind9/bin/named/./server.c:9438:11 (named+0x510c66)
    #5 ns_server_reconfigcommand /builds/isc-projects/bind9/bin/named/./server.c:9773:2 (named+0x510b41)
    #6 ns_control_docommand /builds/isc-projects/bind9/bin/named/control.c:243:12 (named+0x4e451a)
    #7 control_recvmessage /builds/isc-projects/bind9/bin/named/controlconf.c:465:13 (named+0x4e9056)
    #8 dispatch /builds/isc-projects/bind9/lib/isc/task.c:1157:7 (libisc.so.1107+0x507d5)
    #9 run /builds/isc-projects/bind9/lib/isc/task.c:1331:2 (libisc.so.1107+0x4d729)

  Mutex M987831431424375936 previously acquired by the same thread here:
    #0 pthread_mutex_lock <null> (named+0x4642a6)
    #1 dns_view_setviewcommit /builds/isc-projects/bind9/lib/dns/view.c:2382:2 (libdns.so.1110+0x1cfde7)
    #2 load_configuration /builds/isc-projects/bind9/bin/named/./server.c:8188:3 (named+0x51eadd)
    #3 loadconfig /builds/isc-projects/bind9/bin/named/./server.c:9438:11 (named+0x510c66)
    #4 ns_server_reconfigcommand /builds/isc-projects/bind9/bin/named/./server.c:9773:2 (named+0x510b41)
    #5 ns_control_docommand /builds/isc-projects/bind9/bin/named/control.c:243:12 (named+0x4e451a)
    #6 control_recvmessage /builds/isc-projects/bind9/bin/named/controlconf.c:465:13 (named+0x4e9056)
    #7 dispatch /builds/isc-projects/bind9/lib/isc/task.c:1157:7 (libisc.so.1107+0x507d5)
    #8 run /builds/isc-projects/bind9/lib/isc/task.c:1331:2 (libisc.so.1107+0x4d729)

  Mutex M987831431424375936 acquired here while holding mutex M1012319771577875480 in thread T7:
    #0 pthread_mutex_lock <null> (named+0x4642a6)
    #1 dns_view_findzonecut2 /builds/isc-projects/bind9/lib/dns/view.c:1300:2 (libdns.so.1110+0x1cc93a)
    #2 dns_view_findzonecut /builds/isc-projects/bind9/lib/dns/view.c:1261:9 (libdns.so.1110+0x1cc864)
    #3 fctx_create /builds/isc-projects/bind9/lib/dns/resolver.c:4459:13 (libdns.so.1110+0x1779d3)
    #4 dns_resolver_createfetch3 /builds/isc-projects/bind9/lib/dns/resolver.c:9628:12 (libdns.so.1110+0x176cb6)
    #5 dns_resolver_createfetch /builds/isc-projects/bind9/lib/dns/resolver.c:9504:10 (libdns.so.1110+0x174e17)
    #6 zone_refreshkeys /builds/isc-projects/bind9/lib/dns/zone.c:10061:12 (libdns.so.1110+0x2055a5)
    #7 zone_maintenance /builds/isc-projects/bind9/lib/dns/zone.c:10274:5 (libdns.so.1110+0x203a78)
    #8 zone_timer /builds/isc-projects/bind9/lib/dns/zone.c:13106:2 (libdns.so.1110+0x1e815a)
    #9 dispatch /builds/isc-projects/bind9/lib/isc/task.c:1157:7 (libisc.so.1107+0x507d5)
    #10 run /builds/isc-projects/bind9/lib/isc/task.c:1331:2 (libisc.so.1107+0x4d729)

  Mutex M1012319771577875480 previously acquired by the same thread here:
    #0 pthread_mutex_lock <null> (named+0x4642a6)
    #1 zone_refreshkeys /builds/isc-projects/bind9/lib/dns/zone.c:9951:2 (libdns.so.1110+0x204dc3)
    #2 zone_maintenance /builds/isc-projects/bind9/lib/dns/zone.c:10274:5 (libdns.so.1110+0x203a78)
    #3 zone_timer /builds/isc-projects/bind9/lib/dns/zone.c:13106:2 (libdns.so.1110+0x1e815a)
    #4 dispatch /builds/isc-projects/bind9/lib/isc/task.c:1157:7 (libisc.so.1107+0x507d5)
    #5 run /builds/isc-projects/bind9/lib/isc/task.c:1331:2 (libisc.so.1107+0x4d729)

  Thread T2 'isc-worker0001' (tid=9163, running) created by main thread at:
    #0 pthread_create <null> (named+0x446edb)
    #1 isc_thread_create /builds/isc-projects/bind9/lib/isc/pthreads/thread.c:60:8 (libisc.so.1107+0x726d8)
    #2 isc__taskmgr_create /builds/isc-projects/bind9/lib/isc/task.c:1468:7 (libisc.so.1107+0x4d635)
    #3 isc_taskmgr_create /builds/isc-projects/bind9/lib/isc/task.c:2109:11 (libisc.so.1107+0x4f587)
    #4 create_managers /builds/isc-projects/bind9/bin/named/./main.c:886:11 (named+0x4f1a97)
    #5 setup /builds/isc-projects/bind9/bin/named/./main.c:1305:11 (named+0x4f05ee)
    #6 main /builds/isc-projects/bind9/bin/named/./main.c:1556:2 (named+0x4ef12d)

  Thread T7 'isc-worker0006' (tid=9168, running) created by main thread at:
    #0 pthread_create <null> (named+0x446edb)
    #1 isc_thread_create /builds/isc-projects/bind9/lib/isc/pthreads/thread.c:60:8 (libisc.so.1107+0x726d8)
    #2 isc__taskmgr_create /builds/isc-projects/bind9/lib/isc/task.c:1468:7 (libisc.so.1107+0x4d635)
    #3 isc_taskmgr_create /builds/isc-projects/bind9/lib/isc/task.c:2109:11 (libisc.so.1107+0x4f587)
    #4 create_managers /builds/isc-projects/bind9/bin/named/./main.c:886:11 (named+0x4f1a97)
    #5 setup /builds/isc-projects/bind9/bin/named/./main.c:1305:11 (named+0x4f05ee)
    #6 main /builds/isc-projects/bind9/bin/named/./main.c:1556:2 (named+0x4ef12d)

SUMMARY: ThreadSanitizer: lock-order-inversion (potential deadlock) (/builds/isc-projects/bind9/bin/named/.libs/named+0x4642a6) in pthread_mutex_lock
(cherry picked from commit cdcfde9e656b7a730f210de33d798131330022aa)

diff --git a/lib/dns/view.c b/lib/dns/view.c
index d994a5ac2c239388235e6c78f6d8868960be2638..f4070ff50145b5fee643ee667b69ac59e0a7d3d3 100644 (file)
--- a/lib/dns/view.c
+++ b/lib/dns/view.c
@@ -2457,25 +2457,37 @@ cleanup:
 
 void
 dns_view_setviewcommit(dns_view_t *view) {
+       dns_zone_t *redirect = NULL, *managed_keys = NULL;
+
        REQUIRE(DNS_VIEW_VALID(view));
 
        LOCK(&view->lock);
 
        if (view->redirect != NULL) {
-               dns_zone_setviewcommit(view->redirect);
+               dns_zone_attach(view->redirect, &redirect);
        }
        if (view->managed_keys != NULL) {
-               dns_zone_setviewcommit(view->managed_keys);
+               dns_zone_attach(view->managed_keys, &managed_keys);
        }
        if (view->zonetable != NULL) {
                dns_zt_setviewcommit(view->zonetable);
        }
 
        UNLOCK(&view->lock);
+
+       if (redirect != NULL) {
+               dns_zone_setviewcommit(redirect);
+               dns_zone_detach(&redirect);
+       }
+       if (managed_keys != NULL) {
+               dns_zone_setviewcommit(managed_keys);
+               dns_zone_detach(&managed_keys);
+       }
 }
 
 void
 dns_view_setviewrevert(dns_view_t *view) {
+       dns_zone_t *redirect = NULL, *managed_keys = NULL;
        dns_zt_t *zonetable;
 
        REQUIRE(DNS_VIEW_VALID(view));
@@ -2486,14 +2498,22 @@ dns_view_setviewrevert(dns_view_t *view) {
         */
        LOCK(&view->lock);
        if (view->redirect != NULL) {
-               dns_zone_setviewrevert(view->redirect);
+               dns_zone_attach(view->redirect, &redirect);
        }
        if (view->managed_keys != NULL) {
-               dns_zone_setviewrevert(view->managed_keys);
+               dns_zone_attach(view->managed_keys, &managed_keys);
        }
        zonetable = view->zonetable;
        UNLOCK(&view->lock);
 
+       if (redirect != NULL) {
+               dns_zone_setviewrevert(redirect);
+               dns_zone_detach(&redirect);
+       }
+       if (managed_keys != NULL) {
+               dns_zone_setviewrevert(managed_keys);
+               dns_zone_detach(&managed_keys);
+       }
        if (zonetable != NULL) {
                dns_zt_setviewrevert(zonetable);
        }