crypto: s390 - fix aes,des ctr mode concurrency finding.

commit 3901c112 upstream.

An additional testcase found an issue with the last
series of patches applied: the fallback solution may
not save the iv value after operation. This very small
fix just makes sure the iv is copied back to the
walk/desc struct.

Cc: <stable@vger.kernel.org> # 3.14+
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

arch/s390/crypto/aes_s390.c

@@ -818,6 +818,9 @@ static int ctr_aes_crypt(struct blkcipher_desc *desc, long func,
 		else
 			memcpy(walk->iv, ctrptr, AES_BLOCK_SIZE);
 		spin_unlock(&ctrblk_lock);
+	} else {
+		if (!nbytes)
+			memcpy(walk->iv, ctrptr, AES_BLOCK_SIZE);
 	}
 	/*
 	 * final block may be < AES_BLOCK_SIZE, copy only nbytes

arch/s390/crypto/des_s390.c

@@ -429,6 +429,9 @@ static int ctr_desall_crypt(struct blkcipher_desc *desc, long func,
 		else
 			memcpy(walk->iv, ctrptr, DES_BLOCK_SIZE);
 		spin_unlock(&ctrblk_lock);
+	} else {
+		if (!nbytes)
+			memcpy(walk->iv, ctrptr, DES_BLOCK_SIZE);
 	}
 	/* final block may be < DES_BLOCK_SIZE, copy only nbytes */
 	if (nbytes) {