From: James Chapman <jchapman@katalix.com>
Date: Mon, 29 Jul 2024 15:38:08 +0000 (+0100)
Subject: l2tp: free sessions using rcu
X-Git-Tag: v6.12-rc1~232^2~355^2~6
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d17e89999574aca143dd4ede43e4382d32d98724;p=thirdparty%2Flinux.git

l2tp: free sessions using rcu

l2tp sessions may be accessed under an rcu read lock. Have them freed
via rcu and remove the now unneeded synchronize_rcu when a session is
removed.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index f6ae18c180bfb..4cf4aa2713535 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -166,7 +166,7 @@ static void l2tp_session_free(struct l2tp_session *session)
 	trace_free_session(session);
 	if (session->tunnel)
 		l2tp_tunnel_dec_refcount(session->tunnel);
-	kfree(session);
+	kfree_rcu(session, rcu);
 }
 
 struct l2tp_tunnel *l2tp_sk_to_tunnel(const struct sock *sk)
@@ -1269,8 +1269,6 @@ static void l2tp_session_unhash(struct l2tp_session *session)
 
 		spin_unlock_bh(&pn->l2tp_session_idr_lock);
 		spin_unlock_bh(&tunnel->list_lock);
-
-		synchronize_rcu();
 	}
 }
 
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index 8d7a589ccd2ad..58d3977870de4 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -66,6 +66,7 @@ struct l2tp_session_coll_list {
 struct l2tp_session {
 	int			magic;		/* should be L2TP_SESSION_MAGIC */
 	long			dead;
+	struct rcu_head		rcu;
 
 	struct l2tp_tunnel	*tunnel;	/* back pointer to tunnel context */
 	u32			session_id;