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[5/5] xfrm: fix rcu lock in xfrm_notify_userpolicy()

Message ID 20211007055524.319785-6-steffen.klassert@secunet.com (mailing list archive)
State Accepted
Commit 93ec1320b0170d7a207eda2d119c669b673401ed
Delegated to: Netdev Maintainers
Headers show
Series pull request (net): ipsec 2021-10-07 | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Steffen Klassert Oct. 7, 2021, 5:55 a.m. UTC 
From: Nicolas Dichtel <nicolas.dichtel@6wind.com>

As stated in the comment above xfrm_nlmsg_multicast(), rcu read lock must
be held before calling this function.

Reported-by: syzbot+3d9866419b4aa8f985d6@syzkaller.appspotmail.com
Fixes: 703b94b93c19 ("xfrm: notify default policy on update")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_user.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 0eba0c27c665..3a3cb09eec12 100644
--- 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,