| From foo@baz Sat Apr 29 08:22:13 CEST 2017 |
| From: Guillaume Nault <g.nault@alphalink.fr> |
| Date: Wed, 29 Mar 2017 08:45:29 +0200 |
| Subject: l2tp: purge socket queues in the .destruct() callback |
| |
| From: Guillaume Nault <g.nault@alphalink.fr> |
| |
| |
| [ Upstream commit e91793bb615cf6cdd59c0b6749fe173687bb0947 ] |
| |
| The Rx path may grab the socket right before pppol2tp_release(), but |
| nothing guarantees that it will enqueue packets before |
| skb_queue_purge(). Therefore, the socket can be destroyed without its |
| queues fully purged. |
| |
| Fix this by purging queues in pppol2tp_session_destruct() where we're |
| guaranteed nothing is still referencing the socket. |
| |
| Fixes: 9e9cb6221aa7 ("l2tp: fix userspace reception on plain L2TP sockets") |
| Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/l2tp/l2tp_ppp.c | 7 ++++--- |
| 1 file changed, 4 insertions(+), 3 deletions(-) |
| |
| --- a/net/l2tp/l2tp_ppp.c |
| +++ b/net/l2tp/l2tp_ppp.c |
| @@ -450,6 +450,10 @@ static void pppol2tp_session_close(struc |
| static void pppol2tp_session_destruct(struct sock *sk) |
| { |
| struct l2tp_session *session = sk->sk_user_data; |
| + |
| + skb_queue_purge(&sk->sk_receive_queue); |
| + skb_queue_purge(&sk->sk_write_queue); |
| + |
| if (session) { |
| sk->sk_user_data = NULL; |
| BUG_ON(session->magic != L2TP_SESSION_MAGIC); |
| @@ -488,9 +492,6 @@ static int pppol2tp_release(struct socke |
| l2tp_session_queue_purge(session); |
| sock_put(sk); |
| } |
| - skb_queue_purge(&sk->sk_receive_queue); |
| - skb_queue_purge(&sk->sk_write_queue); |
| - |
| release_sock(sk); |
| |
| /* This will delete the session context via |
