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

xfrm: Refuse to insert 32 bit userspace socket policies on 64 bit systems

to the 4.4-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: xfrm-refuse-to-insert-32-bit-userspace-socket-policies-on-64-bit-systems.patch and it can be found in the queue-4.4 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 19d7df69fdb2636856dc8919de72fc1bf8f79598 Mon Sep 17 00:00:00 2001

From: Steffen Klassert steffen.klassert@secunet.com Date: Thu, 1 Feb 2018 08:49:23 +0100 Subject: xfrm: Refuse to insert 32 bit userspace socket policies on 64 bit systems

From: Steffen Klassert steffen.klassert@secunet.com

commit 19d7df69fdb2636856dc8919de72fc1bf8f79598 upstream.

We don't have a compat layer for xfrm, so userspace and kernel structures have different sizes in this case. This results in a broken configuration, so refuse to configure socket policies when trying to insert from 32 bit userspace as we do it already with policies inserted via netlink.

Reported-and-tested-by: syzbot+e1a1577ca8bcb47b769a@syzkaller.appspotmail.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com [use is_compat_task() - gregkh] Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- net/xfrm/xfrm_state.c | 5 +++++ 1 file changed, 5 insertions(+)

--- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -1845,6 +1845,11 @@ int xfrm_user_policy(struct sock *sk, in struct xfrm_mgr *km; struct xfrm_policy *pol = NULL;

+#ifdef CONFIG_COMPAT + if (is_compat_task()) + return -EOPNOTSUPP; +#endif + if (!optval && !optlen) { xfrm_sk_policy_insert(sk, XFRM_POLICY_IN, NULL); xfrm_sk_policy_insert(sk, XFRM_POLICY_OUT, NULL);

Patches currently in stable-queue which might be from steffen.klassert@secunet.com are

queue-4.4/xfrm_user-uncoditionally-validate-esn-replay-attribute-struct.patch queue-4.4/xfrm-refuse-to-insert-32-bit-userspace-socket-policies-on-64-bit-systems.patch queue-4.4/net-xfrm-use-preempt-safe-this_cpu_read-in-ipcomp_alloc_tfms.patch