Bug 34867 - Random crash in szone_malloc_should_clear
Summary: Random crash in szone_malloc_should_clear
Alias: None
Product: iOS
Classification: Xamarin
Component: XI runtime ()
Version: XI 9.0 (iOS9)
Hardware: PC Mac OS
: Normal normal
Target Milestone: Untriaged
Assignee: Bugzilla
Depends on:
Reported: 2015-10-14 11:58 UTC by John Miller [MSFT]
Modified: 2016-06-09 13:54 UTC (History)
5 users (show)

Is this bug a regression?: ---
Last known good build:

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Description John Miller [MSFT] 2015-10-14 11:58:41 UTC

   Attached is a crash log from an app that is randomly crashing for unknown reasons. 

   This bug report is to start tracking the issue and ask/collect for information that might help investigate the issue. 

**Build Date & Platform:**

=== Xamarin Studio ===

Version 5.9.7 (build 9)
Installation UUID: a1a11d65-6b26-4444-a7b8-7f95e2136866
Mono 4.0.4 ((detached/cb6d6b2)
GTK+ 2.24.23 (Raleigh theme)

Package version: 400040002

=== Apple Developer Tools ===

Xcode 7.0.1 (8228)
Build 7A1001

=== Xamarin.iOS ===

Version: (Business Edition)
Hash: d230615
Branch: master
Build date: 2015-09-16 17:04:13-0400

=== Xamarin.Android ===

Not Installed

=== Xamarin Android Player ===

Not Installed

=== Xamarin.Mac ===

Not Installed

=== Build Information ===

Release ID: 509070009
Git revision: 31fa64709030b3edb971237780a452a4c69943c4
Build date: 2015-09-17 11:44:37-04
Xamarin addins: b105d33d8cd72911ff2cf3ee0b7715d37e5f19a6

=== Operating System ===

Mac OS X 10.10.5

**Additional Information:**

   Rodrigo had taken a look at the crash log originally.
Comment 2 Rodrigo Kumpera 2015-10-14 12:03:00 UTC
Hi Sebastien,

By any chance have you guys seen this crash and have a clue on what triggers it?
Comment 3 Rolf Bjarne Kvinge [MSFT] 2015-10-14 12:15:47 UTC
My guess is that this is some sort of memory corruption in the ObjC class data.

Some way to reproduce the crash would likely be required to figure out what's going on (with memory corruption it's very unlikely we'll be able to track it down with crash reports, since the crash usually occurs a long time after the memory was corrupted).
Comment 4 Sebastien Pouliot 2015-10-14 12:52:11 UTC
@John it's not something we have seen before. We'll need a way to duplicate the issue (even if it's not easy to reproduce).
Comment 7 Rolf Bjarne Kvinge [MSFT] 2015-10-15 03:48:17 UTC
@Joseph, that stack trace isn't fully symbolicated (several frames with "No matching symbols  found:undefined"). Are crash reports symbolicated properly if you get them from Xcode's Organizer instead? Or can you try with a debug build and see if that's properly symbolicated?

I'd try to get to the bottom of this issue first (it's easier to diagnose than a random memory corruption, it's a good lead as anything else, and Objective-C exceptions can theoretically corrupt memory as well).
Comment 8 Sebastien Pouliot 2016-06-09 13:54:56 UTC
We have not received the requested information. If you are still experiencing this issue please provide all the requested information and re-open the bug report. Thanks!