diff mbox series

[5.10,1/1] xfrm: fix rcu lock in xfrm_notify_userpolicy()

Message ID 20230114205850.176370-2-pchelkin@ispras.ru (mailing list archive)
State Not Applicable
Delegated to: Netdev Maintainers
Headers show
Series xfrm: fix rcu lock in xfrm_notify_userpolicy() | expand

Checks

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

Commit Message

Fedor Pchelkin Jan. 14, 2023, 8:58 p.m. UTC 
From: Nicolas Dichtel <nicolas.dichtel@6wind.com>

commit 93ec1320b0170d7a207eda2d119c669b673401ed upstream.

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: 9856c3a129dd ("xfrm: notify default policy on update")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
---
 net/xfrm/xfrm_user.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index d9841f44487f..b5a517916895 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1920,6 +1920,7 @@  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)
@@ -1938,7 +1939,10 @@  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 bool xfrm_userpolicy_is_valid(__u8 policy)