Patch "cifs: Fix smbencrypt() to stop pointing a scatterlist at the stack" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    cifs: Fix smbencrypt() to stop pointing a scatterlist at the stack

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cifs-fix-smbencrypt-to-stop-pointing-a-scatterlist-at-the-stack.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 06deeec77a5a689cc94b21a8a91a76e42176685d Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@kernel.org>
Date: Mon, 12 Dec 2016 12:54:37 -0800
Subject: cifs: Fix smbencrypt() to stop pointing a scatterlist at the stack

From: Andy Lutomirski <luto@kernel.org>

commit 06deeec77a5a689cc94b21a8a91a76e42176685d upstream.

smbencrypt() points a scatterlist to the stack, which is breaks if
CONFIG_VMAP_STACK=y.

Fix it by switching to crypto_cipher_encrypt_one().  The new code
should be considerably faster as an added benefit.

This code is nearly identical to some code that Eric Biggers
suggested.

Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/cifs/smbencrypt.c |   40 ++++++++--------------------------------
 1 file changed, 8 insertions(+), 32 deletions(-)

--- a/fs/cifs/smbencrypt.c
+++ b/fs/cifs/smbencrypt.c
@@ -23,7 +23,7 @@
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
 
-#include <crypto/skcipher.h>
+#include <linux/crypto.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
@@ -69,46 +69,22 @@ str_to_key(unsigned char *str, unsigned
 static int
 smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
 {
-	int rc;
 	unsigned char key2[8];
-	struct crypto_skcipher *tfm_des;
-	struct scatterlist sgin, sgout;
-	struct skcipher_request *req;
+	struct crypto_cipher *tfm_des;
 
 	str_to_key(key, key2);
 
-	tfm_des = crypto_alloc_skcipher("ecb(des)", 0, CRYPTO_ALG_ASYNC);
+	tfm_des = crypto_alloc_cipher("des", 0, 0);
 	if (IS_ERR(tfm_des)) {
-		rc = PTR_ERR(tfm_des);
 		cifs_dbg(VFS, "could not allocate des crypto API\n");
-		goto smbhash_err;
+		return PTR_ERR(tfm_des);
 	}
 
-	req = skcipher_request_alloc(tfm_des, GFP_KERNEL);
-	if (!req) {
-		rc = -ENOMEM;
-		cifs_dbg(VFS, "could not allocate des crypto API\n");
-		goto smbhash_free_skcipher;
-	}
-
-	crypto_skcipher_setkey(tfm_des, key2, 8);
-
-	sg_init_one(&sgin, in, 8);
-	sg_init_one(&sgout, out, 8);
-
-	skcipher_request_set_callback(req, 0, NULL, NULL);
-	skcipher_request_set_crypt(req, &sgin, &sgout, 8, NULL);
-
-	rc = crypto_skcipher_encrypt(req);
-	if (rc)
-		cifs_dbg(VFS, "could not encrypt crypt key rc: %d\n", rc);
-
-	skcipher_request_free(req);
+	crypto_cipher_setkey(tfm_des, key2, 8);
+	crypto_cipher_encrypt_one(tfm_des, out, in);
+	crypto_free_cipher(tfm_des);
 
-smbhash_free_skcipher:
-	crypto_free_skcipher(tfm_des);
-smbhash_err:
-	return rc;
+	return 0;
 }
 
 static int


Patches currently in stable-queue which might be from luto@kernel.org are

queue-4.9/cifs-fix-smbencrypt-to-stop-pointing-a-scatterlist-at-the-stack.patch