From 42c601ae14cd2b9526ae54d674a7d3f47dda969c Mon Sep 17 00:00:00 2001 From: Matthijs Mekking Date: Mon, 21 Jun 2021 11:36:50 +0200 Subject: [PATCH] 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. --- lib/dns/zone.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/lib/dns/zone.c b/lib/dns/zone.c index 8497e23c0b..0755baf636 100644 --- 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);