livepatch: Improve error handling in klp_disable_func()

Minfei Huang · Jiri Kosina · commit 225f58fbcc02 · 2015-07-14T22:48:06.000+02:00
In case of func-&gt;state or func-&gt;old_addr not having expected values,
we'd rather bail out immediately from klp_disable_func().

This can't really happen with the current codebase, but fix this
anyway in the sake of robustness.

[jkosina@suse.com: reworded the changelog a bit]
Signed-off-by: Minfei Huang &lt;mnfhuang@gmail.com&gt;
Acked-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.com&gt;
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
@@ -348,8 +348,10 @@ static void klp_disable_func(struct klp_func *func)
 {
 	struct klp_ops *ops;
 
-	WARN_ON(func->state != KLP_ENABLED);
-	WARN_ON(!func->old_addr);
+	if (WARN_ON(func->state != KLP_ENABLED))
+		return;
+	if (WARN_ON(!func->old_addr))
+		return;
 
 	ops = klp_find_ops(func->old_addr);
 	if (WARN_ON(!ops))
