From patchwork Wed Feb 3 14:02:11 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 578052 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 44EA3140C67; Thu, 4 Feb 2016 01:03:28 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1aQy1k-00075r-Ln; Wed, 03 Feb 2016 14:03:24 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1aQy0c-0006V3-B8 for kernel-team@lists.ubuntu.com; Wed, 03 Feb 2016 14:02:14 +0000 Received: from av-217-129-142-138.netvisao.pt ([217.129.142.138] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1aQy0b-0005Jw-Cy; Wed, 03 Feb 2016 14:02:13 +0000 From: Luis Henriques To: Herbert Xu Subject: [3.16.y-ckt stable] Patch "crypto: af_alg - Disallow bind/setkey/... after accept(2)" has been added to the 3.16.y-ckt tree Date: Wed, 3 Feb 2016 14:02:11 +0000 Message-Id: <1454508131-31363-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Cc: kernel-team@lists.ubuntu.com, Dmitry Vyukov X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled crypto: af_alg - Disallow bind/setkey/... after accept(2) to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt24. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From 529382a7cc33f5e12f54e44caa2bf09a5ad1fec0 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 30 Dec 2015 11:47:53 +0800 Subject: crypto: af_alg - Disallow bind/setkey/... after accept(2) commit c840ac6af3f8713a71b4d2363419145760bd6044 upstream. Each af_alg parent socket obtained by socket(2) corresponds to a tfm object once bind(2) has succeeded. An accept(2) call on that parent socket creates a context which then uses the tfm object. Therefore as long as any child sockets created by accept(2) exist the parent socket must not be modified or freed. This patch guarantees this by using locks and a reference count on the parent socket. Any attempt to modify the parent socket will fail with EBUSY. Reported-by: Dmitry Vyukov Signed-off-by: Herbert Xu [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques --- crypto/af_alg.c | 35 ++++++++++++++++++++++++++++++++--- include/crypto/if_alg.h | 8 +++----- 2 files changed, 35 insertions(+), 8 deletions(-) diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 1de4beeb25f8..abb828a3e424 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -125,6 +125,23 @@ int af_alg_release(struct socket *sock) } EXPORT_SYMBOL_GPL(af_alg_release); +void af_alg_release_parent(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + bool last; + + sk = ask->parent; + ask = alg_sk(sk); + + lock_sock(sk); + last = !--ask->refcnt; + release_sock(sk); + + if (last) + sock_put(sk); +} +EXPORT_SYMBOL_GPL(af_alg_release_parent); + static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) { struct sock *sk = sock->sk; @@ -132,6 +149,7 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) struct sockaddr_alg *sa = (void *)uaddr; const struct af_alg_type *type; void *private; + int err; if (sock->state == SS_CONNECTED) return -EINVAL; @@ -157,16 +175,22 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) return PTR_ERR(private); } + err = -EBUSY; lock_sock(sk); + if (ask->refcnt) + goto unlock; swap(ask->type, type); swap(ask->private, private); + err = 0; + +unlock: release_sock(sk); alg_do_release(type, private); - return 0; + return err; } static int alg_setkey(struct sock *sk, char __user *ukey, @@ -199,11 +223,15 @@ static int alg_setsockopt(struct socket *sock, int level, int optname, struct sock *sk = sock->sk; struct alg_sock *ask = alg_sk(sk); const struct af_alg_type *type; - int err = -ENOPROTOOPT; + int err = -EBUSY; lock_sock(sk); + if (ask->refcnt) + goto unlock; + type = ask->type; + err = -ENOPROTOOPT; if (level != SOL_ALG || !type) goto unlock; @@ -254,7 +282,8 @@ int af_alg_accept(struct sock *sk, struct socket *newsock) sk2->sk_family = PF_ALG; - sock_hold(sk); + if (!ask->refcnt++) + sock_hold(sk); alg_sk(sk2)->parent = sk; alg_sk(sk2)->type = type; diff --git a/include/crypto/if_alg.h b/include/crypto/if_alg.h index d61c11170213..2f38daaab3d7 100644 --- a/include/crypto/if_alg.h +++ b/include/crypto/if_alg.h @@ -30,6 +30,8 @@ struct alg_sock { struct sock *parent; + unsigned int refcnt; + const struct af_alg_type *type; void *private; }; @@ -64,6 +66,7 @@ int af_alg_register_type(const struct af_alg_type *type); int af_alg_unregister_type(const struct af_alg_type *type); int af_alg_release(struct socket *sock); +void af_alg_release_parent(struct sock *sk); int af_alg_accept(struct sock *sk, struct socket *newsock); int af_alg_make_sg(struct af_alg_sgl *sgl, void __user *addr, int len, @@ -80,11 +83,6 @@ static inline struct alg_sock *alg_sk(struct sock *sk) return (struct alg_sock *)sk; } -static inline void af_alg_release_parent(struct sock *sk) -{ - sock_put(alg_sk(sk)->parent); -} - static inline void af_alg_init_completion(struct af_alg_completion *completion) { init_completion(&completion->completion);