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] [day] [month] [year] [list]
Message-ID: <20160113070332.GD8169@gondor.apana.org.au>
Date:	Wed, 13 Jan 2016 15:03:32 +0800
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	Dmitry Vyukov <dvyukov@...gle.com>
Cc:	"David S. Miller" <davem@...emloft.net>,
	linux-crypto@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
	syzkaller <syzkaller@...glegroups.com>,
	Kostya Serebryany <kcc@...gle.com>,
	Alexander Potapenko <glider@...gle.com>,
	Sasha Levin <sasha.levin@...cle.com>,
	Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH 4/4] crypto: af_alg - Forbid bind(2) when nokey child sockets
 are present

This patch forbids the calling of bind(2) when there are child
sockets created by accept(2) in existence, even if they are created
on the nokey path.

This is needed as those child sockets have references to the tfm
object which bind(2) will destroy.

Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index e7cb836..f5e18c2 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -130,19 +130,16 @@ EXPORT_SYMBOL_GPL(af_alg_release);
 void af_alg_release_parent(struct sock *sk)
 {
 	struct alg_sock *ask = alg_sk(sk);
-	bool last;
+	unsigned int nokey = ask->nokey_refcnt;
+	bool last = nokey && !ask->refcnt;
 
 	sk = ask->parent;
-
-	if (ask->nokey_refcnt && !ask->refcnt) {
-		sock_put(sk);
-		return;
-	}
-
 	ask = alg_sk(sk);
 
 	lock_sock(sk);
-	last = !--ask->refcnt;
+	ask->nokey_refcnt -= nokey;
+	if (!last)
+		last = !--ask->refcnt;
 	release_sock(sk);
 
 	if (last)
@@ -188,7 +185,7 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 
 	err = -EBUSY;
 	lock_sock(sk);
-	if (ask->refcnt)
+	if (ask->refcnt | ask->nokey_refcnt)
 		goto unlock;
 
 	swap(ask->type, type);
@@ -306,6 +303,7 @@ int af_alg_accept(struct sock *sk, struct socket *newsock)
 
 	if (nokey || !ask->refcnt++)
 		sock_hold(sk);
+	ask->nokey_refcnt += nokey;
 	alg_sk(sk2)->parent = sk;
 	alg_sk(sk2)->type = type;
 	alg_sk(sk2)->nokey_refcnt = nokey;
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ