[PATCH ipsec] xfrm: fix rcu lock in xfrm_notify_userpolicy()
From: Nicolas Dichtel <hidden>
Date: 2021-09-22 08:58:44
Also in:
lkml
Subsystem:
networking [general], networking [ipsec], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Steffen Klassert, Herbert Xu, Linus Torvalds
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 <redacted>
---
net/xfrm/xfrm_user.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
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,
--
2.33.0