Patch "crypto: af_alg - whitelist mask and type" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    crypto: af_alg - whitelist mask and type

to the 4.4-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:
     crypto-af_alg-whitelist-mask-and-type.patch
and it can be found in the queue-4.4 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 bb30b8848c85e18ca7e371d0a869e94b3e383bdf Mon Sep 17 00:00:00 2001
From: Stephan Mueller <smueller@chronox.de>
Date: Tue, 2 Jan 2018 08:55:25 +0100
Subject: crypto: af_alg - whitelist mask and type

From: Stephan Mueller <smueller@chronox.de>

commit bb30b8848c85e18ca7e371d0a869e94b3e383bdf upstream.

The user space interface allows specifying the type and mask field used
to allocate the cipher. Only a subset of the possible flags are intended
for user space. Therefore, white-list the allowed flags.

In case the user space caller uses at least one non-allowed flag, EINVAL
is returned.

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 crypto/af_alg.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -149,7 +149,7 @@ EXPORT_SYMBOL_GPL(af_alg_release_parent)
 
 static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 {
-	const u32 forbidden = CRYPTO_ALG_INTERNAL;
+	const u32 allowed = CRYPTO_ALG_KERN_DRIVER_ONLY;
 	struct sock *sk = sock->sk;
 	struct alg_sock *ask = alg_sk(sk);
 	struct sockaddr_alg *sa = (void *)uaddr;
@@ -157,6 +157,10 @@ static int alg_bind(struct socket *sock,
 	void *private;
 	int err;
 
+	/* If caller uses non-allowed flag, return error. */
+	if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
+		return -EINVAL;
+
 	if (sock->state == SS_CONNECTED)
 		return -EINVAL;
 
@@ -175,9 +179,7 @@ static int alg_bind(struct socket *sock,
 	if (IS_ERR(type))
 		return PTR_ERR(type);
 
-	private = type->bind(sa->salg_name,
-			     sa->salg_feat & ~forbidden,
-			     sa->salg_mask & ~forbidden);
+	private = type->bind(sa->salg_name, sa->salg_feat, sa->salg_mask);
 	if (IS_ERR(private)) {
 		module_put(type->owner);
 		return PTR_ERR(private);


Patches currently in stable-queue which might be from smueller@chronox.de are

queue-4.4/crypto-af_alg-whitelist-mask-and-type.patch
queue-4.4/crypto-aesni-handle-zero-length-dst-buffer.patch