From: Andy Whitcroft <apw@xxxxxxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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@xxxxxxxxxxxxx> Acked-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> --- net/xfrm/xfrm_user.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 9a6bd448468d..52fe9a77a1b1 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -390,7 +390,11 @@ 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) -- 2.12.2