[llvm-commits] Fix a use-after-return in AddressSanitizer runtime

[Alexander Potapenko]

Uh-oh, then that's really a coincidence. Sorry for the false alarm.
Then we really need to poison all the internal structures to see
what's going on there.

On Thu, Dec 15, 2011 at 9:31 PM, Kostya Serebryany <kcc at google.com> wrote:
> Could you please describe what the bug is?
>
> I see that we have a use-after-return in __asan_register_global(uintptr_t
> addr, size_t size, const char *name)
> but this function is only used by the gcc variant which I did not touch for
> ages. (Still, OMG)
>
> In void __asan_register_globals(__asan_global *globals, size_t n),
> which is used by the LLVM variant, I don't see a use-after-return.
>
> (I like the idea to poison the memory allocated by LowLevelAllocator, I'll
> land a patch shortly).
>
> --kcc
>
>
> On Thu, Dec 15, 2011 at 7:32 AM, Alexander Potapenko <glider at google.com>
> wrote:
>>
>> The attached patch fixes a use-after-return in ASan runtime.
>> Previously stack-local objects representing global variables were
>> passed to RegisterGlobal and put into the globals list that was
>> scanned later, when those objects had been overwritten.
>>
>> Related changes: s/Print/Report in RegisterGlobal (we may need the
>> PIDs when analyzing the logs), poison the memory returned by the
>> LowLevelAllocator to prevent possible corruptions.
>>
>>
>> Alexander Potapenko
>> Software Engineer
>> Google Moscow
>
>



-- 
Alexander Potapenko
Software Engineer
Google Moscow