[PATCH ipsec-next v3 0/2] IPsec: do not ignore crypto err in ah input

[PATCH ipsec-next v3 0/2] IPsec: do not ignore crypto err in ah input

[Gilad Ben-Yossef]

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 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>
CC: Alexander Alemayhu <alexander@alemayhu.com>
---

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

Changes from v2:
- Added fix for same problem in IPv6 pointed out by Steffen Klassert

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

Gilad Ben-Yossef (2):
  IPsec: do not ignore crypto err in ah4 input
  IPsec: do not ignore crypto err in ah6 input

 net/ipv4/ah4.c | 3 +++
 net/ipv6/ah6.c | 3 +++
 2 files changed, 6 insertions(+)

-- 
2.1.4

[PATCH ipsec-next v3 1/2] IPsec: do not ignore crypto err in ah4 input

[Gilad Ben-Yossef]

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>
---
 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

[PATCH ipsec-next v3 2/2] IPsec: do not ignore crypto err in ah6 input

[Gilad Ben-Yossef]

ah6 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>
---
 net/ipv6/ah6.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index 189eb10..dda6035 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -474,6 +474,9 @@ static void ah6_input_done(struct crypto_async_request *base, int err)
 	int hdr_len = skb_network_header_len(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, hdr_len);
 	icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
-- 
2.1.4

Re: [PATCH ipsec-next v3 0/2] IPsec: do not ignore crypto err in ah input

[Steffen Klassert]

On Mon, Jan 16, 2017 at 01:17:54PM +0200, Gilad Ben-Yossef wrote:
> 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 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>
> CC: Alexander Alemayhu <alexander@alemayhu.com>

Both applied to ipsec-next, thanks a lot!