netdev - [PATCHv2 net 2/2] l2tp: fix userspace reception on plain L2TP sockets

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 6 Mar 2014 11:15:10 +0100
From:	Guillaume Nault <g.nault@...halink.fr>
To:	netdev@...r.kernel.org
Cc:	James Chapman <jchapman@...alix.com>,
	"David S. Miller" <davem@...emloft.net>
Subject: [PATCHv2 net 2/2] l2tp: fix userspace reception on plain L2TP sockets

As pppol2tp_recv() never queues up packets to plain L2TP sockets,
pppol2tp_recvmsg() never returns data to userspace, thus making
the recv*() system calls unusable.

Instead of dropping packets when the L2TP socket isn't bound to a PPP
channel, this patch adds them to its reception queue.

Signed-off-by: Guillaume Nault <g.nault@...halink.fr>
---
 net/l2tp/l2tp_ppp.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 6bfeaa7..5990919 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -254,12 +254,14 @@ static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int
 		po = pppox_sk(sk);
 		ppp_input(&po->chan, skb);
 	} else {
-		l2tp_info(session, PPPOL2TP_MSG_DATA, "%s: socket not bound\n",
-			  session->name);
+		l2tp_dbg(session, PPPOL2TP_MSG_DATA,
+			 "%s: recv %d byte data frame, passing to L2TP socket\n",
+			 session->name, data_len);
 
-		/* Not bound. Nothing we can do, so discard. */
-		atomic_long_inc(&session->stats.rx_errors);
-		kfree_skb(skb);
+		if (sock_queue_rcv_skb(sk, skb) < 0) {
+			atomic_long_inc(&session->stats.rx_errors);
+			kfree_skb(skb);
+		}
 	}
 
 	return;
-- 
1.9.0

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html