From: Suman Anna <s-anna@ti.com>
Date: Sat, 2 Feb 2013 02:30:09 +0000 (-0600)
Subject: mailbox: check for NULL nb in mailbox_put
X-Git-Tag: next-20130322~15^2~1
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6275aa1ae16b73f0391f9be199af1c64845a62b1;p=karo-tx-linux.git

mailbox: check for NULL nb in mailbox_put

The mailbox_put function must check the notifier block for
NULL before trying to unregister it.

Signed-off-by: Fernando Guzman Lugo <lugo.fernando@gmail.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
---

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index eaaf87ec9009..c38241a8b44a 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -473,7 +473,8 @@ EXPORT_SYMBOL(mailbox_get);
 
 void mailbox_put(struct mailbox *mbox, struct notifier_block *nb)
 {
-	blocking_notifier_chain_unregister(&mbox->notifier, nb);
+	if (nb)
+		blocking_notifier_chain_unregister(&mbox->notifier, nb);
 	mailbox_fini(mbox);
 }
 EXPORT_SYMBOL(mailbox_put);