[Bug sanitizer/107586] gcc trunk missed a stack-buffer-overflow

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107586

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |INVALID
             Status|ASSIGNED                    |RESOLVED

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
If I hide the constant 70, then I get the error also with -O2:

diff -u pr107586-orig.c pr107586.c
--- pr107586-orig.c     2022-12-02 14:19:49.392836836 +0100
+++ pr107586.c  2022-12-02 14:19:33.096414298 +0100
@@ -3,13 +3,15 @@
     int x;
 };

+int N = 70;
+
 void h(struct a *b)
 {
     struct a c[70];
     int i;
-    for (i = 0; i < 70; i++)
+    for (i = 0; i < N; i++)
         c[i].x = 1;
-    __builtin_memcpy(b, c, 70*sizeof(struct a));
+    __builtin_memcpy(b, c, N*sizeof(struct a));
     __builtin_printf("%d\n", b->x);
 };
 void g()

So the compiler can propagate that, so closing as invalid.