From: Gilad Ben-Yossef <gilad@benyossef.com>
Date: Mon, 16 Jan 2017 11:17:55 +0000 (+0200)
Subject: IPsec: do not ignore crypto err in ah4 input
X-Git-Tag: v3.18.81~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9d913538108b380bb9b0a5fc47086220807151e4;p=thirdparty%2Fkernel%2Fstable.git

IPsec: do not ignore crypto err in ah4 input


[ Upstream commit ebd89a2d0675f1325c2be5b7576fd8cb7e8defd0 ]

ah4 input processing uses the asynchronous hash crypto API which
supplies an error code as part of the operation completion but
the error code was being ignored.

Treat a crypto API error indication as a verification failure.

While a crypto API reported error would almost certainly result
in a memcpy of the digest failing anyway and thus the security
risk seems minor, performing a memory compare on what might be
uninitialized memory is wrong.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index ac9a32ec3ee46..0157f09c0de97 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -270,6 +270,9 @@ static void ah_input_done(struct crypto_async_request *base, int err)
 	int ihl = ip_hdrlen(skb);
 	int ah_hlen = (ah->hdrlen + 2) << 2;
 
+	if (err)
+		goto out;
+
 	work_iph = AH_SKB_CB(skb)->tmp;
 	auth_data = ah_tmp_auth(work_iph, ihl);
 	icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);