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authorAndy Whitcroft <apw@canonical.com>2017-03-23 07:45:44 +0000
committerBen Hutchings <ben@decadent.org.uk>2017-06-05 21:17:20 +0100
commitfda265baa45b630675359db3699bb68350c4b907 (patch)
treed1b122fd6bdc9d27497c6ef121038145e58154fa
parent811f5600db1a0a9c4f1abad5017e09f43d7088f3 (diff)
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> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--net/xfrm/xfrm_user.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index a0db0cf4b6b5..a6d54a9a1133 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -387,7 +387,11 @@ 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)