[PATCH v2 net-next] IPsec: do not ignore crypto err in ah input

Subsystems: networking [general], networking [ipsec], the rest

STALE3505d

2 messages, 2 authors, 2017-01-16 · open the first message on its own page

[PATCH v2 net-next] IPsec: do not ignore crypto err in ah input

From: Gilad Ben-Yossef <gilad@benyossef.com>
Date: 2017-01-15 06:09:53

ah 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 
memcmp 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>
CC: Alexander Alemayhu <redacted>
---

The change was boot tested on Arm64 but I did not exercise
the specific error code path in question.

Changes from v1:
- Fixed typo in patch description pointed out by Alexander

 net/ipv4/ah4.c | 3 +++
 1 file changed, 3 insertions(+)
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index f2a7102..22377c8 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);
-- 
2.1.4

Re: [PATCH v2 net-next] IPsec: do not ignore crypto err in ah input

From: Steffen Klassert <steffen.klassert@secunet.com>
Date: 2017-01-16 07:35:39

On Sun, Jan 15, 2017 at 08:09:43AM +0200, Gilad Ben-Yossef wrote:
quoted hunk
ah 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 
memcmp 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>
CC: Alexander Alemayhu <redacted>
---

The change was boot tested on Arm64 but I did not exercise
the specific error code path in question.

Changes from v1:
- Fixed typo in patch description pointed out by Alexander

 net/ipv4/ah4.c | 3 +++
 1 file changed, 3 insertions(+)
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index f2a7102..22377c8 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;
+
IPv6 has the same problem, can we get it fixed there too?

Thanks!
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