This is a note to let you know that I've just added the patch titled phonet/pep: refuse to enable an unbound pipe 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: phonet-pep-refuse-to-enable-an-unbound-pipe.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@xxxxxxxxxxxxxxx> know about it. >From 75a2f31520095600f650597c0ac41f48b5ba0068 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?R=C3=A9mi=20Denis-Courmont?= <remi@xxxxxxxxxx> Date: Sun, 19 Dec 2021 19:03:39 +0200 Subject: phonet/pep: refuse to enable an unbound pipe MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Rémi Denis-Courmont <remi@xxxxxxxxxx> commit 75a2f31520095600f650597c0ac41f48b5ba0068 upstream. This ioctl() implicitly assumed that the socket was already bound to a valid local socket name, i.e. Phonet object. If the socket was not bound, two separate problems would occur: 1) We'd send an pipe enablement request with an invalid source object. 2) Later socket calls could BUG on the socket unexpectedly being connected yet not bound to a valid object. Reported-by: syzbot+2dc91e7fc3dea88b1e8a@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Rémi Denis-Courmont <remi@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/phonet/pep.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/phonet/pep.c +++ b/net/phonet/pep.c @@ -956,6 +956,8 @@ static int pep_ioctl(struct sock *sk, in ret = -EBUSY; else if (sk->sk_state == TCP_ESTABLISHED) ret = -EISCONN; + else if (!pn->pn_sk.sobject) + ret = -EADDRNOTAVAIL; else ret = pep_sock_enable(sk, NULL, 0); release_sock(sk); Patches currently in stable-queue which might be from remi@xxxxxxxxxx are queue-4.9/phonet-pep-refuse-to-enable-an-unbound-pipe.patch