| 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: [PATCH] xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder |
| |
| 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> |
| |
| diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c |
| index cdf887fa61d5..40a8aa39220d 100644 |
| --- a/net/xfrm/xfrm_user.c |
| +++ b/net/xfrm/xfrm_user.c |
| @@ -412,7 +412,11 @@ static inline int xfrm_replay_verify_len(struct xfrm_replay_state_esn *replay_es |
| 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) |
| -- |
| 2.12.0 |
| |
