ah: Read nexthdr value before overwriting it in ahash input callback.

commit b7ea81a58adc123a4e980cb0eff9eb5c144b5dc7 upstream.

The AH4/6 ahash input callbacks read out the nexthdr field from the AH
header *after* they overwrite that header.  This is obviously not going
to end well.  Fix it up.

Signed-off-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 33ca18603e3bdb73bb762355d97e226fbc6fa311..c7056b2e831f6d107c3d1aaa993b3b2b6b23f2d1 100644 (file)
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -262,12 +262,12 @@ static void ah_input_done(struct crypto_async_request *base, int err)
        if (err)
                goto out;
 
+       err = ah->nexthdr;
+
        skb->network_header += ah_hlen;
        memcpy(skb_network_header(skb), work_iph, ihl);
        __skb_pull(skb, ah_hlen + ihl);
        skb_set_transport_header(skb, -ihl);
-
-       err = ah->nexthdr;
 out:
        kfree(AH_SKB_CB(skb)->tmp);
        xfrm_input_resume(skb, err);

diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index ede4d9d6cc2b6cd6e94dadcc7a17f4ef3d27a4b8..7a33aaa0022785734a22f7d279e187f65b8072b4 100644 (file)
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -464,12 +464,12 @@ static void ah6_input_done(struct crypto_async_request *base, int err)
        if (err)
                goto out;
 
+       err = ah->nexthdr;
+
        skb->network_header += ah_hlen;
        memcpy(skb_network_header(skb), work_iph, hdr_len);
        __skb_pull(skb, ah_hlen + hdr_len);
        skb_set_transport_header(skb, -hdr_len);
-
-       err = ah->nexthdr;
 out:
        kfree(AH_SKB_CB(skb)->tmp);
        xfrm_input_resume(skb, err);