powerpc/kprobes: Handle error returned by set_memory_rox()

set_memory_rox() can fail.

In case it fails, free allocated memory and return NULL.

Link: https://github.com/KSPP/linux/issues/7
Signed-off-by: Christophe Leroy <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://msgid.link/b4907cf4[e-mail]

arch/powerpc/kernel/kprobes.c

···
 	if (!page)
 		return NULL;
 
-	if (strict_module_rwx_enabled())
-		set_memory_rox((unsigned long)page, 1);
+	if (strict_module_rwx_enabled()) {
+		int err = set_memory_rox((unsigned long)page, 1);
 
+		if (err)
+			goto error;
+	}
 	return page;
+error:
+	module_memfree(page);
+	return NULL;
 }
 
 int arch_prepare_kprobe(struct kprobe *p)