icaltimezone.c - Fix a multi-threaded deadlock in icaltimezone_load_builtin_timezone()

2 files changed, 4 insertions, 1 deletions

diff --git a/ReleaseNotes.txt b/ReleaseNotes.txt
index 0e03329c..9487fc2e 100644
--- a/ReleaseNotes.txt
+++ b/ReleaseNotes.txt
@@ -4,6 +4,7 @@ Release Highlights
 Version 3.0.1:
 --------------
  * Built-in timezones updated to tzdata2017c
+ * Fix a multi-threaded deadlock in icaltimezone_load_builtin_timezone()
 
 Version 3.0.0:
 --------------
diff --git a/src/libical/icaltimezone.c b/src/libical/icaltimezone.c
index 7ed36414..070b1252 100644
--- a/src/libical/icaltimezone.c
+++ b/src/libical/icaltimezone.c
@@ -1821,8 +1821,10 @@ static void icaltimezone_load_builtin_timezone(icaltimezone *zone)
     icaltimezone_builtin_lock();
 
     /* If the location isn't set, it isn't a builtin timezone. */
-    if (!zone->location || !zone->location[0])
+    if (!zone->location || !zone->location[0]) {
+        icaltimezone_builtin_unlock();
         return;
+    }
 
     if (use_builtin_tzdata) {
         char *filename;