diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 39f6211..dc1d8e8 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -219,10 +219,6 @@
 	if (!x->aalg)
 		goto error;
 
-	/* null auth can use a zero length key */
-	if (x->aalg->alg_key_len > 512)
-		goto error;
-
 	if (x->encap)
 		goto error;
 
@@ -230,14 +226,13 @@
 	if (ahp == NULL)
 		return -ENOMEM;
 
-	ahp->key = x->aalg->alg_key;
-	ahp->key_len = (x->aalg->alg_key_len+7)/8;
 	tfm = crypto_alloc_hash(x->aalg->alg_name, 0, CRYPTO_ALG_ASYNC);
 	if (IS_ERR(tfm))
 		goto error;
 
 	ahp->tfm = tfm;
-	if (crypto_hash_setkey(tfm, ahp->key, ahp->key_len))
+	if (crypto_hash_setkey(tfm, x->aalg->alg_key,
+			       (x->aalg->alg_key_len + 7) / 8))
 		goto error;
 
 	/*