From: Andy Whitcroft Date: Thu, 23 Mar 2017 07:45:44 +0000 (+0000) Subject: xfrm_user: validate XFRM_MSG_NEWAE incoming ESN size harder X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~18^2~12 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=22c9e7c092f63335ba7a7301e0e0b4c4ebed53a8;p=firefly-linux-kernel-4.4.55.git 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 Acked-by: Steffen Klassert Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 0e1f833bc77d..7a5a64e70b4d 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)