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/* an example that should be protected by FORTIFY_SOURCE=2 but
* only if the appropriate -fstrict-flex-arrays= argument is used
* for the corresponding value used for BUFFER_DEF_SIZE
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct buffer_with_header {
char header[1];
char buffer[BUFFER_DEF_SIZE];
};
int main(int argc, char *argv[]) {
/* use volatile pointer to prevent compiler
* using the outer allocation length with a
* fortified strcpy, which would throw off
* the function-name-sniffing fortify-detecting
* approaches
*/
struct buffer_with_header *volatile b = \
(struct buffer_with_header *)malloc(sizeof(struct buffer_with_header)+1);
/* if there are no arguments, skip the write to allow
* builds with BUFFER_DEF_SIZE=0 to have a case where
* the program passes even with strict protection.
*/
if (argc > 1) {
strcpy(b->buffer, argv[1]);
puts(b->buffer);
}
return 0;
}
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