Patch "xfrm: policy: check policy direction value" has been added to the 4.9-stable tree

Patch "xfrm: policy: check policy direction value" 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

    xfrm: policy: check policy direction value

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:
     xfrm-policy-check-policy-direction-value.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 7bab09631c2a303f87a7eb7e3d69e888673b9b7e Mon Sep 17 00:00:00 2001
From: Vladis Dronov <vdronov@redhat.com>
Date: Wed, 2 Aug 2017 19:50:14 +0200
Subject: xfrm: policy: check policy direction value

From: Vladis Dronov <vdronov@redhat.com>

commit 7bab09631c2a303f87a7eb7e3d69e888673b9b7e upstream.

The 'dir' parameter in xfrm_migrate() is a user-controlled byte which is used
as an array index. This can lead to an out-of-bound access, kernel lockup and
DoS. Add a check for the 'dir' value.

This fixes CVE-2017-11600.

References: https://bugzilla.redhat.com/show_bug.cgi?id=1474928
Fixes: 80c9abaabf42 ("[XFRM]: Extension for dynamic update of endpoint address(es)")
Reported-by: "bo Zhang" <zhangbo5891001@gmail.com>
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/xfrm/xfrm_policy.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -3308,9 +3308,15 @@ int xfrm_migrate(const struct xfrm_selec
 	struct xfrm_state *x_new[XFRM_MAX_DEPTH];
 	struct xfrm_migrate *mp;
 
+	/* Stage 0 - sanity checks */
 	if ((err = xfrm_migrate_check(m, num_migrate)) < 0)
 		goto out;
 
+	if (dir >= XFRM_POLICY_MAX) {
+		err = -EINVAL;
+		goto out;
+	}
+
 	/* Stage 1 - find policy */
 	if ((pol = xfrm_migrate_policy_find(sel, dir, type, net)) == NULL) {
 		err = -ENOENT;


Patches currently in stable-queue which might be from vdronov@redhat.com are

queue-4.9/xfrm-policy-check-policy-direction-value.patch