lkml.org 
[lkml]   [2017]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 3.16 187/212] xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder
3.16.44-rc1 review patch.  If anyone has any objections, please let me know.

------------------

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: Ben Hutchings <ben@decadent.org.uk>
---
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
@@ -387,7 +387,11 @@ 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)
\
 
 \ /
  Last update: 2017-06-01 17:56    [W:0.790 / U:0.200 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site