Saving PFObject - PFMD5HashFromData Crash

[rudywen]

My app intermittently gets into a cyclic reference state when the saving an object calls [PFObject isDirty]. This usually happens when we try to save objects after the app detects a network connection is avaliable (i.e. turn off airplane mode). We're using Parse 1.8.2

https://groups.google.com/forum/#!searchin/parse-developers/isDirty$20crash/parse-developers/lzhRkGnvrx0/uVkPvDRf_DQJ

Crashed: com.apple.root.default-qos
EXC_BAD_ACCESS KERN_PROTECTION_FAILURE at 0x00000001033bbfb8

Thread : Crashed: com.apple.root.default-qos
0 libsystem_c.dylib 0x00000001965fdd24 __vfprintf + 36
1 libsystem_c.dylib 0x000000019661b680 __v2printf + 588
2 libsystem_c.dylib 0x000000019661b680 __v2printf + 588
3 libsystem_c.dylib 0x00000001965ae20c _vsnprintf + 304
4 libsystem_c.dylib 0x00000001965aec58 snprintf_l + 24
5 CoreFoundation 0x000000018469f01c __CFStringAppendFormatCore + 11584
6 CoreFoundation 0x000000018469c2a4 _CFStringCreateWithFormatAndArgumentsAux2 + 248
7 Foundation 0x00000001854e2448 -[NSPlaceholderString initWithFormat:locale:arguments:] + 172
8 Foundation 0x00000001854e2308 +[NSString stringWithFormat:] + 76
9 flare 0x000000010014a25c PFMD5HashFromData (PFHash.m:59)
10 flare 0x000000010014ec54 -PFJSONCacheItem initWithObject:
11 flare 0x000000010014edd4 +PFJSONCacheItem cacheFromObject:
12 flare 0x000000010015af70 -PFObject(Private) checkForChangesToMutableContainer:forKey:
13 flare 0x000000010015b28c __55-[PFObject(Private) checkForChangesToMutableContainers]_block_invoke (PFObject.m:805)
14 CoreFoundation 0x00000001846287a4 __65-[__NSDictionaryI enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 88
15 CoreFoundation 0x0000000184615cec -[__NSDictionaryI enumerateKeysAndObjectsWithOptions:usingBlock:] + 240
16 flare 0x000000010015b174 -PFObject(Private) checkForChangesToMutableContainers
17 flare 0x000000010015a8d8 -PFObject(Private) isDirty:
18 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
19 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
20 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
21 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
22 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
23 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
24 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
25 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
26 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
27 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
28 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
29 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
30 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
31 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
32 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
33 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
34 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
35 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
36 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
37 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
38 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
39 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
40 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
41 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
42 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
43 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
44 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
45 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
46 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
47 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
48 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
49 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
50 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)
51 CoreFoundation 0x00000001845bdd40 __65-[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:]_block_invoke + 124
52 CoreFoundation 0x00000001845bdc20 -[__NSDictionaryM enumerateKeysAndObjectsWithOptions:usingBlock:] + 204
53 flare 0x000000010015a9e8 -PFObject(Private) isDirty:
54 flare 0x000000010015aa9c __29-[PFObject(Private) isDirty:]_block_invoke (PFObject.m:740)

[richardjrossiii]

Thanks for the report. We'll definitely look into it. Is there any chance you can also post the stack trace produced by thread backtrace all in lldb? It will show us the parameters passed to every function in the call stack, which is extremely useful in tracking down issues like this.

Any chance you could also create a small repro project here on GitHub?

[rudywen]

Here is the crash report saved on fabric.
http://crashes.to/s/4aca5333f4c

[nlutsenko]

Looks related to #97, since this code is no longer executed at all after #97 is merged in.

[magnett]

I see the same crash on crashlytics and i don't know what is triggering it
http://crashes.to/s/afcefe8c455

[rudywen]

I'm still seeing this issue with the Parse SDK 1.8.3.

http://crashes.to/s/01cc10338f1

Seems to occur more when I'm retrieving and saving objects at the same time.

[richardjrossiii]

I misread the stack trace before. It is a much deeper bug, although the issue before was still valid. I'll have a PR ready in a few hours. Thanks for your patience!

A workaround for now is to not have a recursive relationship inside your object model, though that may not always be possible. (e.g. A -> B -> A).