[Bug c/56458] New: support for crash on invalid array access

[Bug c/56458] New: support for crash on invalid array access

[wbrana at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56458

             Bug #: 56458
           Summary: support for crash on invalid array access
    Classification: Unclassified
           Product: gcc
           Version: 4.7.3
            Status: UNCONFIRMED
          Severity: enhancement
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: wbrana@gmail.com


GCC could support command-line flag for at least C and C++, which would enable
checking of array access, which would increase security.
If wrong access is detected, process should crash, but following code returns
two zeros. 

#include <iostream>
using namespace std;

int array[5];

inline void crash() {
        int* v = 0;
        *v = 0;
}

int read1(int i) {
        return array[i];
}

int write1(int i) {
        return array[i] = 0;
}

int main(int i, char* argv[]) {
        cout << read1(i + 100) << endl;
        cout << write1(i + 100) << endl;
        return 0;
}

[Bug c/56458] support for crash on invalid array access

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56458

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-02-26 11:49:13 UTC ---
GCC supports -fmudflap and starting with 4.8 also -fsanitize=address.  The
latter might not detect access off by 100 bytes, but if it is <= 32 (or often
up to < 64) bytes, it will be detected.