[for-4.9,4/5] l2tp: hold session while sending creation notifications

Message ID 1498492039-26905-5-git-send-email-amit.pundir@linaro.org
State New
Headers show
Series
  • l2tp session lookup fixes
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Commit Message

Amit Pundir June 26, 2017, 3:47 p.m.
From: Guillaume Nault <g.nault@alphalink.fr>


commit 5e6a9e5a3554a5b3db09cdc22253af1849c65dff upstream.

l2tp_session_find() doesn't take any reference on the returned session.
Therefore, the session may disappear while sending the notification.

Use l2tp_session_get() instead and decrement session's refcount once
the notification is sent.

Fixes: 33f72e6f0c67 ("l2tp : multicast notification to the registered listeners")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>

Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

---
 net/l2tp/l2tp_netlink.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

-- 
2.7.4

Patch

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 9f66272b163b..8c0f48350027 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -634,10 +634,12 @@  static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 			session_id, peer_session_id, &cfg);
 
 	if (ret >= 0) {
-		session = l2tp_session_find(net, tunnel, session_id);
-		if (session)
+		session = l2tp_session_get(net, tunnel, session_id, false);
+		if (session) {
 			ret = l2tp_session_notify(&l2tp_nl_family, info, session,
 						  L2TP_CMD_SESSION_CREATE);
+			l2tp_session_dec_refcount(session);
+		}
 	}
 
 out: