Fix deadlock issue with key-directory and in-view

When locking key files for a zone, we iterate over all the views and
lock a mutex inside the zone structure. However, if we envounter an
in-view zone, we will try to lock the key files twice, one time for
the home view and one time for the in-view view. This will lead to
a deadlock because one thread is trying to get the same lock twice.

diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 8497e23c0b9308ec3d9c66985fdf563a03f69004..0755baf63646c771cc43a41c79a830741dc50c1c 100644 (file)
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -6395,6 +6395,17 @@ dns__zone_lockunlock_keyfiles(dns_zone_t *zone, bool lock) {
                if (ret == ISC_R_SUCCESS) {
                        INSIST(DNS_ZONE_VALID(z));
 
+                       /*
+                        * Skip in-view zones, in other words if the view
+                        * pointer is not the same as the zone view pointer:
+                        * 'in-view' zones can be part of another view,
+                        * while they also have their own home view.
+                        */
+                       if (v != z->view) {
+                               dns_zone_detach(&z);
+                               continue;
+                       }
+
                        /* WMM check if policy is the same? */
                        if (lock) {
                                LOCK_KEYFILES(z);