#80 Recursive crash in icaltimezone_load_builtin_timezone

[Antony]

When converting a time to a time with zone, the code will incorrectly recuse causing a crash. Logic when the recursion starts is shown in the call stack below

icaltime_convert_to_zone
icaltimezone_convert_time
icaltimezone_get_utc_offset_of_utc_time
icaltimezone_ensure_coverage
icaltimezone_load_builtin_timezone
icalcomponent_remove_component
icaltimezone_get_component
icaltimezone_load_builtin_timezone
...

So, the problem is that during the icalcomponent_remove_component() call it will call the icaltimezone_load_builtin_timezone again.

[Antony]

libical is built with -DUSE_BUILTIN_TZDATA and it's running on Windows

[Allen Winter]

Antony,

Does commenting out the icalcomponent_remove_component(comp,subcomp) on line1831 help?

[Antony]

Allen, not sure about that as I implemented something back in November that I posted on the list. In icaltimezone_load_builtin_timezone, I added the lines below with >>>>>

#ifdef HAVE_PTHREAD
pthread_mutex_lock(&builtin_mutex);
if (zone->component)
goto out;
>>>>>#else
>>>>>#ifdef USE_BUILTIN_TZDATA
>>>>> if (zone->component)
>>>>> return;
>>>>>#endif
#endif

That seemed to work and it's in use in production now and we've not had any problems. At least in the debugger, it appeared to work in a sensible way.