realloc() with the debug library does not catch a straight forward corruption

realloc() with the debug library does not catch a straight forward corruption by Michael Burr

Closed

Type:	Bug
ID:	773479
Opened:	12/4/2012 7:07:55 PM
Access Restriction:	Public

Workaround(s)

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User(s) can reproduce this bug

If a program overwrites the 'no man's land' just past the end of an allocation, the debug version of realloc() doesn't notice that. free() does (as it should).

Details (expand)

Visual Studio 2012

Compile and run the following program with a debug configuration:

#include <stdlib.h>

int main()
{
    int* p = (int*) calloc(10,sizeof(*p));

    p[10] = 0; // this overwrites memory filled with _bNoMansLandFill

    // free(p); // with the debug libray, free() catches the corruption

    // realloc does not, but I think it should
    p = (int*) realloc( p, 80);

    return 0;
}

English

Windows 7 SP1

English

The Debug version of realloc() does not notice corrupted memory.

A notification that memory is corrupted similar to what occurs when free() is called instead of realloc().

0 attachments

Posted by Microsoft on 1/25/2013 at 1:49 PM

Hello,

Thanks for suggesting this feature. Due to other higher priority work items however, we have decided not to address this issue in the next release of the product. We will keep it in our database for future consideration.

Thank you,
Visual C++ Team

Posted by Microsoft on 12/7/2012 at 2:21 AM

Thank you for submitting feedback on Visual Studio and .NET Framework. Your issue has been routed to the appropriate VS development team for investigation. We will contact you if we require any additional information.

Posted by Microsoft on 12/4/2012 at 7:51 PM

Thank you for your feedback, we are currently reviewing the issue you have submitted. If this issue is urgent, please contact support directly(http://support.microsoft.com)

Posted by NARESHK BANKER on 12/4/2012 at 7:19 PM

IF REALLOCATION NOT PROPER STAND AND WHITE PAPERS USES IT WILL BE CORRUPTED FILES.