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 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: crypto-af_alg-whitelist-mask-and-type.patch and it can be found in the queue-4.15 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 @@ -150,7 +150,7 @@ 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; @@ -158,6 +158,10 @@ 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;

@@ -176,9 +180,7 @@ 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-4.15/crypto-af_alg-whitelist-mask-and-type.patch queue-4.15/crypto-aesni-handle-zero-length-dst-buffer.patch