Application Crashing due to EXC_BAD_ACCESS

Question

Exception Type: EXC_BAD_ACCESS (SIGBUS) Exception Codes: KERN_PROTECTION_FAILURE at 0x00000000 Crashed Thread: 0

Thread 0 Crashed:
0   libobjc.A.dylib                 0x00004420 objc_msgSend + 24
1   CoreFoundation                  0x000042a6 CFRetain + 54
2   CoreFoundation                  0x0000a9f0 __CFBasicHashStandardRetainValue + 8
3   CoreFoundation                  0x000054c0 __CFBasicHashAddValue + 100
4   CoreFoundation                  0x00006184 CFBasicHashAddValue + 276
5   CoreFoundation                  0x00006cfe CFDictionaryCreate + 58
6   CoreFoundation                  0x00033d7c -[__NSPlaceholderDictionary initWithObjects:forKeys:count:] + 1456
7   CoreFoundation                  0x000361bc -[NSDictionary initWithObjectsAndKeys:] + 776
8   iota                            0x0000c4cc 0x1000 + 46284
9   iota                            0x00009282 0x1000 + 33410
10  iota                            0x0000952a 0x1000 + 34090
11  Foundation                      0x00015432 _nsnote_callback + 150
12  CoreFoundation                  0x000271da __CFXNotificationPost_old + 390
13  CoreFoundation                  0x00026e7a _CFXNotificationPostNotification + 122
14  Foundation                      0x0000b9f6 -[NSNotificationCenter postNotification:] + 138
15  Foundation                      0x0007ae02 postQueueNotifications + 258
16  Foundation                      0x0007afae __NSPostIdleQueueNotes + 6
17  CoreFoundation                  0x00031084 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 12
18  CoreFoundation                  0x00030eb2 __CFRunLoopDoObservers + 494
19  CoreFoundation                  0x00028206 __CFRunLoopRun + 934
20  CoreFoundation                  0x00027d74 CFRunLoopRunSpecific + 220
21  CoreFoundation                  0x00027c82 CFRunLoopRunInMode + 54
22  GraphicsServices                0x00004e84 GSEventRunModal + 188
23  UIKit                           0x00004f8c -[UIApplication _run] + 564
24  UIKit                           0x000024cc UIApplicationMain + 964
25  iota                            0x0000533a 0x1000 + 17210
26  iota                            0x000052fc 0x1000 + 17148


NSDictionary *contactNameDictionary = [[NSDictionary alloc] initWithObjectsAndKeys:item, @"contact", sortName, @"contactSortName", compositeName, @"compositeName", nil];

The crashes are random. Like it happens once in 15 trials of a particular action.

Answer 1

KERN_PROTECTION_FAILURE - means that your program is accessing a shared memory that it didn't have access to. That's why kenel sent killed your process. I'm pretty sure that some of your pointers point to wrong location. E.g.

NSObject* obj;

obj would have garbage as it's value. You have to declare it like this:

NSObject* obj = nil;

Answer 2

Without more info, it's hard to say. Usually it's because you try to access/insert into your dictionary an object that doesn't exist anymore.

Answer 3

Check if you're not inserting something that is not an instance of NSObject, like an int or something.

Answer 4

Given that you are using initWithObjectsAndKeys:, make sure that you have nil-terminated the list of arguments, as that's a common mistake that can lead to crashes.