Patch "xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

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

    xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder

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_user-validate-xfrm_msg_newae-incoming-esn-size-harder.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 f843ee6dd019bcece3e74e76ad9df0155655d0df Mon Sep 17 00:00:00 2001
From: Andy Whitcroft <apw@canonical.com>
Date: Thu, 23 Mar 2017 07:45:44 +0000
Subject: xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder

From: Andy Whitcroft <apw@canonical.com>

commit f843ee6dd019bcece3e74e76ad9df0155655d0df upstream.

Kees Cook has pointed out that xfrm_replay_state_esn_len() is subject to
wrapping issues.  To ensure we are correctly ensuring that the two ESN
structures are the same size compare both the overall size as reported
by xfrm_replay_state_esn_len() and the internal length are the same.

CVE-2017-7184
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/xfrm/xfrm_user.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -412,7 +412,11 @@ static inline int xfrm_replay_verify_len
 	up = nla_data(rp);
 	ulen = xfrm_replay_state_esn_len(up);
 
-	if (nla_len(rp) < ulen || xfrm_replay_state_esn_len(replay_esn) != ulen)
+	/* Check the overall length and the internal bitmap length to avoid
+	 * potential overflow. */
+	if (nla_len(rp) < ulen ||
+	    xfrm_replay_state_esn_len(replay_esn) != ulen ||
+	    replay_esn->bmp_len != up->bmp_len)
 		return -EINVAL;
 
 	if (up->replay_window > up->bmp_len * sizeof(__u32) * 8)


Patches currently in stable-queue which might be from apw@canonical.com are

queue-4.9/xfrm_user-validate-xfrm_msg_newae-incoming-esn-size-harder.patch
queue-4.9/xfrm_user-validate-xfrm_msg_newae-xfrma_replay_esn_val-replay_window.patch