linux-kernel - [PATCH 4.4 15/67] crypto: af_alg

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri,  2 Feb 2018 17:57:44 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, syzbot <syzkaller@...glegroups.com>,
        Stephan Mueller <smueller@...onox.de>,
        Herbert Xu <herbert@...dor.apana.org.au>
Subject: [PATCH 4.4 15/67] crypto: af_alg - whitelist mask and type

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stephan Mueller <smueller@...onox.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@...glegroups.com>
Signed-off-by: Stephan Mueller <smueller@...onox.de>
Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.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);