xfrm: fix rcu lock in xfrm_notify_userpolicy()

As stated in the comment above xfrm_nlmsg_multicast(), rcu read lock must be held before calling this function. Reported-by: [email protected] Fixes: 703b94b93c19 ("xfrm: notify default policy on update") Signed-off-by: Nicolas Dichtel <[email protected]> Signed-off-by: Steffen Klassert <[email protected]>
fracktal · Sep 23, 2021 · 93ec132 · 93ec132
1 parent 047a749
commit 93ec132
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
@@ -1967,6 +1967,7 @@ static int xfrm_notify_userpolicy(struct net *net)
 	int len = NLMSG_ALIGN(sizeof(*up));
 	struct nlmsghdr *nlh;
 	struct sk_buff *skb;
+	int err;
 
 	skb = nlmsg_new(len, GFP_ATOMIC);
 	if (skb == NULL)
@@ -1988,7 +1989,11 @@ static int xfrm_notify_userpolicy(struct net *net)
 
 	nlmsg_end(skb, nlh);
 
-	return xfrm_nlmsg_multicast(net, skb, 0, XFRMNLGRP_POLICY);
+	rcu_read_lock();
+	err = xfrm_nlmsg_multicast(net, skb, 0, XFRMNLGRP_POLICY);
+	rcu_read_unlock();
+
+	return err;
 }
 
 static int xfrm_set_default(struct sk_buff *skb, struct nlmsghdr *nlh,