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 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: l2tp-check-ps-sock-before-running-pppol2tp_session_ioctl.patch and it can be found in the queue-4.13 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 17:25:34 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-4.13/ppp-fix-race-in-ppp-device-destruction.patch queue-4.13/l2tp-hold-tunnel-in-pppol2tp_connect.patch queue-4.13/l2tp-check-ps-sock-before-running-pppol2tp_session_ioctl.patch