mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-30 14:31:14 +00:00
a5357b7ce2
A larger number of format specifiers coudld cause a stack overflow, potentially allowing to bypass _FORTIFY_SOURCE format string protection.
32 lines
677 B
C
32 lines
677 B
C
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/resource.h>
|
|
|
|
#define LIMIT 1000000
|
|
|
|
int
|
|
main (void)
|
|
{
|
|
struct rlimit lim;
|
|
getrlimit (RLIMIT_STACK, &lim);
|
|
lim.rlim_cur = 1048576;
|
|
setrlimit (RLIMIT_STACK, &lim);
|
|
char *fmtstr = malloc (4 * LIMIT + 1);
|
|
if (fmtstr == NULL)
|
|
abort ();
|
|
char *output = malloc (LIMIT + 1);
|
|
if (output == NULL)
|
|
abort ();
|
|
for (size_t i = 0; i < LIMIT; i++)
|
|
memcpy (fmtstr + 4 * i, "%1$d", 4);
|
|
fmtstr[4 * LIMIT] = '\0';
|
|
int ret = snprintf (output, LIMIT + 1, fmtstr, 0);
|
|
if (ret != LIMIT)
|
|
abort ();
|
|
for (size_t i = 0; i < LIMIT; i++)
|
|
if (output[i] != '0')
|
|
abort ();
|
|
return 0;
|
|
}
|