ASan reports sometimes contain incorrect statements

[ramosian-glider]

Originally reported on Google Code with ID 150

#include <cstdio>
#include <cstdlib>

int main()
{
  int* q = (int*)malloc(102);
  return q[25];
}

ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60260000aff4 at pc 0x418199
bp 0x7fff42614a30 sp 0x7fff42614a28
READ of size 4 at 0x60260000aff4 thread T0
...
0x60260000aff4 is located 0 bytes to the right of 102-byte region [0x60260000af90,0x60260000aff6)

^ The last line is not true.

Reported by eugenis@google.com on 2013-02-05 11:43:54

[ramosian-glider]

yea, that's a bit wrong. 
How do you suggest to change the output in a way that will not break our users' scripts?

Reported by konstantin.s.serebryany on 2013-02-05 11:50:03

[ramosian-glider]

Just change the address in the last line to the first unaddressable location inside
the access range.

Will that break anything?

Reported by eugenis@google.com on 2013-02-05 11:53:43

[ramosian-glider]

This actually came from looking at ASAN_ACCESS_RANGE. Everything going though that reports
access sizes of 1. Even scanf("%d").

Reported by eugenis@google.com on 2013-02-05 11:54:49

[ramosian-glider]

SGTM

Reported by konstantin.s.serebryany on 2013-02-05 11:55:13

[ramosian-glider]

How about:
a) 0x60260000aff6 is located 0 bytes to the right of 102-byte region [0x60260000af90,0x60260000aff6)

b) 0x60260000aff4 goes out of the 102-byte region [0x60260000af90,0x60260000aff6) bounds

Reported by timurrrr@google.com on 2013-02-05 11:55:29

[ramosian-glider]

b is too large of a change, can break report parsers.

I'm going to implement a).

Reported by eugenis@google.com on 2013-02-05 12:02:39

[ramosian-glider]

r174373.

Reported by eugenis@google.com on 2013-02-05 14:32:36

• Status changed: Fixed

[ramosian-glider]

Adding Project:AddressSanitizer as part of GitHub migration.

Reported by ramosian.glider on 2015-07-30 09:13:40

• Labels added: ProjectAddressSanitizer