lkdtm: Missing kmalloc check

Handling a possible memory allocation failure.

Signed-off-by: Vasyl Gomonovych <[e-mail]>
Acked-by: Kees Cook <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/lkdtm_heap.c

···
 {
 	size_t len = 1020;
 	u32 *data = kmalloc(len, GFP_KERNEL);
+	if (!data)
+		return;
 
 	data[1024 / sizeof(u32)] = 0x12345678;
 	kfree(data);
···
 	size_t offset = (len / sizeof(*base)) / 2;
 
 	base = kmalloc(len, GFP_KERNEL);
+	if (!base)
+		return;
 	pr_info("Allocated memory %p-%p\n", base, &base[offset * 2]);
 	pr_info("Attempting bad write to freed memory at %p\n",
 		&base[offset]);