Fix an Avahi-related crash bug in the scheduler (Issue #5085, Issue #5086)

Add NULL pointer check to avoid Avahi assertion in production code.

diff --git a/CHANGES.md b/CHANGES.md
index 5ac9ec1072e1e590f233ac8bbbda5012a24ef489..2dbd33ff18c1cbc5fca5a9de4e0b181bf9e2af16 100644 (file)
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -26,6 +26,7 @@ CHANGES IN CUPS V2.2.5
   values (Issue #5074)
 - The scheduler now creates a PID file when not running on demand with a modern
   service launcher (Issue #5080)
+- Fixed an Avahi-related crash bug in the scheduler (Issue #5085, Issue #5086)
 - The IPP Everywhere PPD generator now sorts the supported resolutions before
   choosing them for draft, normal, and best quality modes (Issue #5091)
 - Fixed an issue with Chinese localizations on macOS (rdar://32419311)

diff --git a/scheduler/dirsvc.c b/scheduler/dirsvc.c
index 6f6aa8bb446dc38f1ccbd416e39b2ad3771fdfd3..2308e05384bc90552a505590914ce876789b0c6c 100644 (file)
--- a/scheduler/dirsvc.c
+++ b/scheduler/dirsvc.c
@@ -699,13 +699,16 @@ dnssdDeregisterInstance(
   DNSServiceRefDeallocate(*srv);
 
 #  else /* HAVE_AVAHI */
-  if (!from_callback)
-    avahi_threaded_poll_lock(DNSSDMaster);
+  if (*srv)
+  {
+    if (!from_callback)
+      avahi_threaded_poll_lock(DNSSDMaster);
 
-  avahi_entry_group_free(*srv);
+    avahi_entry_group_free(*srv);
 
-  if (!from_callback)
-    avahi_threaded_poll_unlock(DNSSDMaster);
+    if (!from_callback)
+      avahi_threaded_poll_unlock(DNSSDMaster);
+  }
 #  endif /* HAVE_DNSSD */
 
   *srv = NULL;