IPsec: do not ignore crypto err in ah4 input

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>

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index f2a71025a7705d5c7b10dc108440ee2ea5cd03aa..22377c8ff14b72292caa5c2f72898fc60dcfa576 100644 (file)
--- 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);