overflow in tests/example_sig_stfl.c

[wangweij]

Describe the bug

70		sk_fname = malloc(strlen(method_name) + strlen(".sk"));
....
78		strcpy(sk_fname, method_name);
79		strcat(sk_fname, ".sk");

Here, the size of sk_fname is only enough to contain method_name and ".sk" but not the zero at the end of ".sk".

To Reproduce
This is a coding error.

Suggested Fix

-	sk_fname = malloc(strlen(method_name) + strlen(".sk"));
+	sk_fname = malloc(strlen(method_name) + strlen(".sk") + 1);

[SWilson4]

Thanks for the report! Created #1887 to fix.