Patch "l2tp: check ps->sock before running pppol2tp_session_ioctl()" has been added to the 4.9-stable tree

Patch "l2tp: check ps->sock before running pppol2tp_session_ioctl()" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    l2tp: check ps->sock before running pppol2tp_session_ioctl()

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     l2tp-check-ps-sock-before-running-pppol2tp_session_ioctl.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Guillaume Nault <g.nault@alphalink.fr>
Date: Fri, 13 Oct 2017 19:22:35 +0200
Subject: l2tp: check ps->sock before running pppol2tp_session_ioctl()

From: Guillaume Nault <g.nault@alphalink.fr>


[ Upstream commit 5903f594935a3841137c86b9d5b75143a5b7121c ]

When pppol2tp_session_ioctl() is called by pppol2tp_tunnel_ioctl(),
the session may be unconnected. That is, it was created by
pppol2tp_session_create() and hasn't been connected with
pppol2tp_connect(). In this case, ps->sock is NULL, so we need to check
for this case in order to avoid dereferencing a NULL pointer.

Fixes: 309795f4bec2 ("l2tp: Add netlink control API for L2TP")
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 |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -993,6 +993,9 @@ static int pppol2tp_session_ioctl(struct
 		 session->name, cmd, arg);
 
 	sk = ps->sock;
+	if (!sk)
+		return -EBADR;
+
 	sock_hold(sk);
 
 	switch (cmd) {


Patches currently in stable-queue which might be from g.nault@alphalink.fr are

queue-4.9/ppp-fix-race-in-ppp-device-destruction.patch
queue-4.9/l2tp-check-ps-sock-before-running-pppol2tp_session_ioctl.patch