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From:   Casey Schaufler <casey@schaufler-ca.com>
To:     casey.schaufler@intel.com, jmorris@namei.org,
        linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc:     casey@schaufler-ca.com, linux-audit@redhat.com,
        keescook@chromium.org, john.johansen@canonical.com,
        penguin-kernel@i-love.sakura.ne.jp, paul@paul-moore.com,
        stephen.smalley.work@gmail.com, linux-kernel@vger.kernel.org
Subject: [PATCH v37 02/33] LSM: Infrastructure management of the sock security
Date:   Mon, 27 Jun 2022 17:55:40 -0700
Message-Id: <20220628005611.13106-3-casey@schaufler-ca.com>
In-Reply-To: <20220628005611.13106-1-casey@schaufler-ca.com>
References: <20220628005611.13106-1-casey@schaufler-ca.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Move management of the sock->sk_security blob out
of the individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.

Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h         |  1 +
 security/apparmor/include/net.h   |  6 ++-
 security/apparmor/lsm.c           | 38 ++++----------
 security/security.c               | 36 +++++++++++++-
 security/selinux/hooks.c          | 82 +++++++++++++++----------------
 security/selinux/include/objsec.h |  5 ++
 security/selinux/netlabel.c       | 23 ++++-----
 security/smack/smack.h            |  5 ++
 security/smack/smack_lsm.c        | 66 ++++++++++++-------------
 security/smack/smack_netfilter.c  |  4 +-
 10 files changed, 145 insertions(+), 121 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 91c8146649f5..5d480797cf53 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1606,6 +1606,7 @@ struct lsm_blob_sizes {
 	int	lbs_cred;
 	int	lbs_file;
 	int	lbs_inode;
+	int	lbs_sock;
 	int	lbs_superblock;
 	int	lbs_ipc;
 	int	lbs_msg_msg;
diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
index aadb4b29fb66..fac8999ba7a3 100644
--- a/security/apparmor/include/net.h
+++ b/security/apparmor/include/net.h
@@ -51,7 +51,11 @@ struct aa_sk_ctx {
 	struct aa_label *peer;
 };
 
-#define SK_CTX(X) ((X)->sk_security)
+static inline struct aa_sk_ctx *aa_sock(const struct sock *sk)
+{
+	return sk->sk_security + apparmor_blob_sizes.lbs_sock;
+}
+
 #define SOCK_ctx(X) SOCK_INODE(X)->i_security
 #define DEFINE_AUDIT_NET(NAME, OP, SK, F, T, P)				  \
 	struct lsm_network_audit NAME ## _net = { .sk = (SK),		  \
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 900bc540656a..ef9046866b17 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -802,33 +802,15 @@ static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo
 	return error;
 }
 
-/**
- * apparmor_sk_alloc_security - allocate and attach the sk_security field
- */
-static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
-{
-	struct aa_sk_ctx *ctx;
-
-	ctx = kzalloc(sizeof(*ctx), flags);
-	if (!ctx)
-		return -ENOMEM;
-
-	SK_CTX(sk) = ctx;
-
-	return 0;
-}
-
 /**
  * apparmor_sk_free_security - free the sk_security field
  */
 static void apparmor_sk_free_security(struct sock *sk)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
-	SK_CTX(sk) = NULL;
 	aa_put_label(ctx->label);
 	aa_put_label(ctx->peer);
-	kfree(ctx);
 }
 
 /**
@@ -837,8 +819,8 @@ static void apparmor_sk_free_security(struct sock *sk)
 static void apparmor_sk_clone_security(const struct sock *sk,
 				       struct sock *newsk)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
-	struct aa_sk_ctx *new = SK_CTX(newsk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
+	struct aa_sk_ctx *new = aa_sock(newsk);
 
 	if (new->label)
 		aa_put_label(new->label);
@@ -894,7 +876,7 @@ static int apparmor_socket_post_create(struct socket *sock, int family,
 		label = aa_get_current_label();
 
 	if (sock->sk) {
-		struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
+		struct aa_sk_ctx *ctx = aa_sock(sock->sk);
 
 		aa_put_label(ctx->label);
 		ctx->label = aa_get_label(label);
@@ -1079,7 +1061,7 @@ static int apparmor_socket_shutdown(struct socket *sock, int how)
  */
 static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
 	if (!skb->secmark)
 		return 0;
@@ -1092,7 +1074,7 @@ static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
 static struct aa_label *sk_peer_label(struct sock *sk)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
 	if (ctx->peer)
 		return ctx->peer;
@@ -1176,7 +1158,7 @@ static int apparmor_socket_getpeersec_dgram(struct socket *sock,
  */
 static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
 	if (!ctx->label)
 		ctx->label = aa_get_current_label();
@@ -1186,7 +1168,7 @@ static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
 static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
 				      struct request_sock *req)
 {
-	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *ctx = aa_sock(sk);
 
 	if (!skb->secmark)
 		return 0;
@@ -1203,6 +1185,7 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
 	.lbs_cred = sizeof(struct aa_task_ctx *),
 	.lbs_file = sizeof(struct aa_file_ctx),
 	.lbs_task = sizeof(struct aa_task_ctx),
+	.lbs_sock = sizeof(struct aa_sk_ctx),
 };
 
 static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
@@ -1239,7 +1222,6 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
 	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
 
-	LSM_HOOK_INIT(sk_alloc_security, apparmor_sk_alloc_security),
 	LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
 	LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
 
@@ -1791,7 +1773,7 @@ static unsigned int apparmor_ip_postroute(void *priv,
 	if (sk == NULL)
 		return NF_ACCEPT;
 
-	ctx = SK_CTX(sk);
+	ctx = aa_sock(sk);
 	if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
 				    skb->secmark, sk))
 		return NF_ACCEPT;
diff --git a/security/security.c b/security/security.c
index 8b176769dd86..6ce168475181 100644
--- a/security/security.c
+++ b/security/security.c
@@ -29,6 +29,7 @@
 #include <linux/string.h>
 #include <linux/msg.h>
 #include <net/flow.h>
+#include <net/sock.h>
 
 #define MAX_LSM_EVM_XATTR	2
 
@@ -206,6 +207,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
 	lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
 	lsm_set_blob_size(&needed->lbs_ipc, &blob_sizes.lbs_ipc);
 	lsm_set_blob_size(&needed->lbs_msg_msg, &blob_sizes.lbs_msg_msg);
+	lsm_set_blob_size(&needed->lbs_sock, &blob_sizes.lbs_sock);
 	lsm_set_blob_size(&needed->lbs_superblock, &blob_sizes.lbs_superblock);
 	lsm_set_blob_size(&needed->lbs_task, &blob_sizes.lbs_task);
 }
@@ -342,6 +344,7 @@ static void __init ordered_lsm_init(void)
 	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
 	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
 	init_debug("msg_msg blob size    = %d\n", blob_sizes.lbs_msg_msg);
+	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
 	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
 	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
 
@@ -660,6 +663,28 @@ static int lsm_msg_msg_alloc(struct msg_msg *mp)
 	return 0;
 }
 
+/**
+ * lsm_sock_alloc - allocate a composite sock blob
+ * @sock: the sock that needs a blob
+ * @priority: allocation mode
+ *
+ * Allocate the sock blob for all the modules
+ *
+ * Returns 0, or -ENOMEM if memory can't be allocated.
+ */
+static int lsm_sock_alloc(struct sock *sock, gfp_t priority)
+{
+	if (blob_sizes.lbs_sock == 0) {
+		sock->sk_security = NULL;
+		return 0;
+	}
+
+	sock->sk_security = kzalloc(blob_sizes.lbs_sock, priority);
+	if (sock->sk_security == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
 /**
  * lsm_early_task - during initialization allocate a composite task blob
  * @task: the task that needs a blob
@@ -2270,12 +2295,21 @@ EXPORT_SYMBOL(security_socket_getpeersec_dgram);
 
 int security_sk_alloc(struct sock *sk, int family, gfp_t priority)
 {
-	return call_int_hook(sk_alloc_security, 0, sk, family, priority);
+	int rc = lsm_sock_alloc(sk, priority);
+
+	if (unlikely(rc))
+		return rc;
+	rc = call_int_hook(sk_alloc_security, 0, sk, family, priority);
+	if (unlikely(rc))
+		security_sk_free(sk);
+	return rc;
 }
 
 void security_sk_free(struct sock *sk)
 {
 	call_void_hook(sk_free_security, sk);
+	kfree(sk->sk_security);
+	sk->sk_security = NULL;
 }
 
 void security_sk_clone(const struct sock *sk, struct sock *newsk)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 1bbd53321d13..56cada53993b 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4532,7 +4532,7 @@ static int socket_sockcreate_sid(const struct task_security_struct *tsec,
 
 static int sock_has_perm(struct sock *sk, u32 perms)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 
@@ -4589,7 +4589,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
 	isec->initialized = LABEL_INITIALIZED;
 
 	if (sock->sk) {
-		sksec = sock->sk->sk_security;
+		sksec = selinux_sock(sock->sk);
 		sksec->sclass = sclass;
 		sksec->sid = sid;
 		/* Allows detection of the first association on this socket */
@@ -4605,8 +4605,8 @@ static int selinux_socket_post_create(struct socket *sock, int family,
 static int selinux_socket_socketpair(struct socket *socka,
 				     struct socket *sockb)
 {
-	struct sk_security_struct *sksec_a = socka->sk->sk_security;
-	struct sk_security_struct *sksec_b = sockb->sk->sk_security;
+	struct sk_security_struct *sksec_a = selinux_sock(socka->sk);
+	struct sk_security_struct *sksec_b = selinux_sock(sockb->sk);
 
 	sksec_a->peer_sid = sksec_b->sid;
 	sksec_b->peer_sid = sksec_a->sid;
@@ -4621,7 +4621,7 @@ static int selinux_socket_socketpair(struct socket *socka,
 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
 {
 	struct sock *sk = sock->sk;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	u16 family;
 	int err;
 
@@ -4756,7 +4756,7 @@ static int selinux_socket_connect_helper(struct socket *sock,
 					 struct sockaddr *address, int addrlen)
 {
 	struct sock *sk = sock->sk;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	int err;
 
 	err = sock_has_perm(sk, SOCKET__CONNECT);
@@ -4935,9 +4935,9 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
 					      struct sock *other,
 					      struct sock *newsk)
 {
-	struct sk_security_struct *sksec_sock = sock->sk_security;
-	struct sk_security_struct *sksec_other = other->sk_security;
-	struct sk_security_struct *sksec_new = newsk->sk_security;
+	struct sk_security_struct *sksec_sock = selinux_sock(sock);
+	struct sk_security_struct *sksec_other = selinux_sock(other);
+	struct sk_security_struct *sksec_new = selinux_sock(newsk);
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 	int err;
@@ -4969,8 +4969,8 @@ static int selinux_socket_unix_stream_connect(struct sock *sock,
 static int selinux_socket_unix_may_send(struct socket *sock,
 					struct socket *other)
 {
-	struct sk_security_struct *ssec = sock->sk->sk_security;
-	struct sk_security_struct *osec = other->sk->sk_security;
+	struct sk_security_struct *ssec = selinux_sock(sock->sk);
+	struct sk_security_struct *osec = selinux_sock(other->sk);
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 
@@ -5012,7 +5012,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
 				       u16 family)
 {
 	int err = 0;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	u32 sk_sid = sksec->sid;
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
@@ -5045,7 +5045,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
 	int err;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	u16 family = sk->sk_family;
 	u32 sk_sid = sksec->sid;
 	struct common_audit_data ad;
@@ -5113,13 +5113,15 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	return err;
 }
 
-static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
-					    int __user *optlen, unsigned len)
+static int selinux_socket_getpeersec_stream(struct socket *sock,
+					    char __user *optval,
+					    int __user *optlen,
+					    unsigned int len)
 {
 	int err = 0;
 	char *scontext;
 	u32 scontext_len;
-	struct sk_security_struct *sksec = sock->sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sock->sk);
 	u32 peer_sid = SECSID_NULL;
 
 	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
@@ -5179,34 +5181,27 @@ static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *
 
 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
 {
-	struct sk_security_struct *sksec;
-
-	sksec = kzalloc(sizeof(*sksec), priority);
-	if (!sksec)
-		return -ENOMEM;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	sksec->peer_sid = SECINITSID_UNLABELED;
 	sksec->sid = SECINITSID_UNLABELED;
 	sksec->sclass = SECCLASS_SOCKET;
 	selinux_netlbl_sk_security_reset(sksec);
-	sk->sk_security = sksec;
 
 	return 0;
 }
 
 static void selinux_sk_free_security(struct sock *sk)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
-	sk->sk_security = NULL;
 	selinux_netlbl_sk_security_free(sksec);
-	kfree(sksec);
 }
 
 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
-	struct sk_security_struct *newsksec = newsk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
+	struct sk_security_struct *newsksec = selinux_sock(newsk);
 
 	newsksec->sid = sksec->sid;
 	newsksec->peer_sid = sksec->peer_sid;
@@ -5220,7 +5215,7 @@ static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
 	if (!sk)
 		*secid = SECINITSID_ANY_SOCKET;
 	else {
-		struct sk_security_struct *sksec = sk->sk_security;
+		struct sk_security_struct *sksec = selinux_sock(sk);
 
 		*secid = sksec->sid;
 	}
@@ -5230,7 +5225,7 @@ static void selinux_sock_graft(struct sock *sk, struct socket *parent)
 {
 	struct inode_security_struct *isec =
 		inode_security_novalidate(SOCK_INODE(parent));
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
 	    sk->sk_family == PF_UNIX)
@@ -5247,7 +5242,7 @@ static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
 {
 	struct sock *sk = asoc->base.sk;
 	u16 family = sk->sk_family;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
 	int err;
@@ -5305,7 +5300,7 @@ static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
 static int selinux_sctp_assoc_request(struct sctp_association *asoc,
 				      struct sk_buff *skb)
 {
-	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
 	u32 conn_sid;
 	int err;
 
@@ -5338,7 +5333,7 @@ static int selinux_sctp_assoc_request(struct sctp_association *asoc,
 static int selinux_sctp_assoc_established(struct sctp_association *asoc,
 					  struct sk_buff *skb)
 {
-	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
 
 	if (!selinux_policycap_extsockclass())
 		return 0;
@@ -5437,8 +5432,8 @@ static int selinux_sctp_bind_connect(struct sock *sk, int optname,
 static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
 				  struct sock *newsk)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
-	struct sk_security_struct *newsksec = newsk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
+	struct sk_security_struct *newsksec = selinux_sock(newsk);
 
 	/* If policy does not support SECCLASS_SCTP_SOCKET then call
 	 * the non-sctp clone version.
@@ -5455,7 +5450,7 @@ static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk
 static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
 				     struct request_sock *req)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	int err;
 	u16 family = req->rsk_ops->family;
 	u32 connsid;
@@ -5476,7 +5471,7 @@ static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
 static void selinux_inet_csk_clone(struct sock *newsk,
 				   const struct request_sock *req)
 {
-	struct sk_security_struct *newsksec = newsk->sk_security;
+	struct sk_security_struct *newsksec = selinux_sock(newsk);
 
 	newsksec->sid = req->secid;
 	newsksec->peer_sid = req->peer_secid;
@@ -5493,7 +5488,7 @@ static void selinux_inet_csk_clone(struct sock *newsk,
 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
 {
 	u16 family = sk->sk_family;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
@@ -5577,7 +5572,7 @@ static int selinux_tun_dev_attach_queue(void *security)
 static int selinux_tun_dev_attach(struct sock *sk, void *security)
 {
 	struct tun_security_struct *tunsec = security;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	/* we don't currently perform any NetLabel based labeling here and it
 	 * isn't clear that we would want to do so anyway; while we could apply
@@ -5706,7 +5701,7 @@ static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb,
 			return NF_ACCEPT;
 
 		/* standard practice, label using the parent socket */
-		sksec = sk->sk_security;
+		sksec = selinux_sock(sk);
 		sid = sksec->sid;
 	} else
 		sid = SECINITSID_KERNEL;
@@ -5729,7 +5724,7 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
 	sk = skb_to_full_sk(skb);
 	if (sk == NULL)
 		return NF_ACCEPT;
-	sksec = sk->sk_security;
+	sksec = selinux_sock(sk);
 
 	ad.type = LSM_AUDIT_DATA_NET;
 	ad.u.net = &net;
@@ -5822,7 +5817,7 @@ static unsigned int selinux_ip_postroute(void *priv,
 		u32 skb_sid;
 		struct sk_security_struct *sksec;
 
-		sksec = sk->sk_security;
+		sksec = selinux_sock(sk);
 		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
 			return NF_DROP;
 		/* At this point, if the returned skb peerlbl is SECSID_NULL
@@ -5851,7 +5846,7 @@ static unsigned int selinux_ip_postroute(void *priv,
 	} else {
 		/* Locally generated packet, fetch the security label from the
 		 * associated socket. */
-		struct sk_security_struct *sksec = sk->sk_security;
+		struct sk_security_struct *sksec = selinux_sock(sk);
 		peer_sid = sksec->sid;
 		secmark_perm = PACKET__SEND;
 	}
@@ -5900,7 +5895,7 @@ static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
 	unsigned int data_len = skb->len;
 	unsigned char *data = skb->data;
 	struct nlmsghdr *nlh;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	u16 sclass = sksec->sclass;
 	u32 perm;
 
@@ -6899,6 +6894,7 @@ struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
 	.lbs_inode = sizeof(struct inode_security_struct),
 	.lbs_ipc = sizeof(struct ipc_security_struct),
 	.lbs_msg_msg = sizeof(struct msg_security_struct),
+	.lbs_sock = sizeof(struct sk_security_struct),
 	.lbs_superblock = sizeof(struct superblock_security_struct),
 };
 
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 2953132408bf..007d1ae7ee27 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -194,4 +194,9 @@ static inline struct superblock_security_struct *selinux_superblock(
 	return superblock->s_security + selinux_blob_sizes.lbs_superblock;
 }
 
+static inline struct sk_security_struct *selinux_sock(const struct sock *sock)
+{
+	return sock->sk_security + selinux_blob_sizes.lbs_sock;
+}
+
 #endif /* _SELINUX_OBJSEC_H_ */
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 1321f15799e2..800ab4b4239e 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -17,6 +17,7 @@
 #include <linux/gfp.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
+#include <linux/lsm_hooks.h>
 #include <net/sock.h>
 #include <net/netlabel.h>
 #include <net/ip.h>
@@ -68,7 +69,7 @@ static int selinux_netlbl_sidlookup_cached(struct sk_buff *skb,
 static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk)
 {
 	int rc;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr *secattr;
 
 	if (sksec->nlbl_secattr != NULL)
@@ -101,7 +102,7 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr(
 							const struct sock *sk,
 							u32 sid)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr;
 
 	if (secattr == NULL)
@@ -236,7 +237,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
 	 * being labeled by it's parent socket, if it is just exit */
 	sk = skb_to_full_sk(skb);
 	if (sk != NULL) {
-		struct sk_security_struct *sksec = sk->sk_security;
+		struct sk_security_struct *sksec = selinux_sock(sk);
 
 		if (sksec->nlbl_state != NLBL_REQSKB)
 			return 0;
@@ -274,7 +275,7 @@ int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
 {
 	int rc;
 	struct netlbl_lsm_secattr secattr;
-	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(asoc->base.sk);
 	struct sockaddr_in addr4;
 	struct sockaddr_in6 addr6;
 
@@ -355,7 +356,7 @@ int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
  */
 void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	if (family == PF_INET)
 		sksec->nlbl_state = NLBL_LABELED;
@@ -373,8 +374,8 @@ void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
  */
 void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
-	struct sk_security_struct *newsksec = newsk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
+	struct sk_security_struct *newsksec = selinux_sock(newsk);
 
 	newsksec->nlbl_state = sksec->nlbl_state;
 }
@@ -392,7 +393,7 @@ void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk)
 int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
 {
 	int rc;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr *secattr;
 
 	if (family != PF_INET && family != PF_INET6)
@@ -507,7 +508,7 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
 {
 	int rc = 0;
 	struct sock *sk = sock->sk;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr secattr;
 
 	if (selinux_netlbl_option(level, optname) &&
@@ -545,7 +546,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk,
 						struct sockaddr *addr)
 {
 	int rc;
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 	struct netlbl_lsm_secattr *secattr;
 
 	/* connected sockets are allowed to disconnect when the address family
@@ -584,7 +585,7 @@ static int selinux_netlbl_socket_connect_helper(struct sock *sk,
 int selinux_netlbl_socket_connect_locked(struct sock *sk,
 					 struct sockaddr *addr)
 {
-	struct sk_security_struct *sksec = sk->sk_security;
+	struct sk_security_struct *sksec = selinux_sock(sk);
 
 	if (sksec->nlbl_state != NLBL_REQSKB &&
 	    sksec->nlbl_state != NLBL_CONNLABELED)
diff --git a/security/smack/smack.h b/security/smack/smack.h
index fc837dcebf96..ef9d0b7b1954 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -363,6 +363,11 @@ static inline struct superblock_smack *smack_superblock(
 	return superblock->s_security + smack_blob_sizes.lbs_superblock;
 }
 
+static inline struct socket_smack *smack_sock(const struct sock *sock)
+{
+	return sock->sk_security + smack_blob_sizes.lbs_sock;
+}
+
 /*
  * Is the directory transmuting?
  */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 6207762dbdb1..2689486160a2 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1434,7 +1434,7 @@ static int smack_inode_getsecurity(struct user_namespace *mnt_userns,
 		if (sock == NULL || sock->sk == NULL)
 			return -EOPNOTSUPP;
 
-		ssp = sock->sk->sk_security;
+		ssp = smack_sock(sock->sk);
 
 		if (strcmp(name, XATTR_SMACK_IPIN) == 0)
 			isp = ssp->smk_in;
@@ -1817,7 +1817,7 @@ static int smack_file_receive(struct file *file)
 
 	if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
 		sock = SOCKET_I(inode);
-		ssp = sock->sk->sk_security;
+		ssp = smack_sock(sock->sk);
 		tsp = smack_cred(current_cred());
 		/*
 		 * If the receiving process can't write to the
@@ -2237,11 +2237,7 @@ static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
 {
 	struct smack_known *skp = smk_of_current();
-	struct socket_smack *ssp;
-
-	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
-	if (ssp == NULL)
-		return -ENOMEM;
+	struct socket_smack *ssp = smack_sock(sk);
 
 	/*
 	 * Sockets created by kernel threads receive web label.
@@ -2255,11 +2251,10 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
 	}
 	ssp->smk_packet = NULL;
 
-	sk->sk_security = ssp;
-
 	return 0;
 }
 
+#ifdef SMACK_IPV6_PORT_LABELING
 /**
  * smack_sk_free_security - Free a socket blob
  * @sk: the socket
@@ -2268,7 +2263,6 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
  */
 static void smack_sk_free_security(struct sock *sk)
 {
-#ifdef SMACK_IPV6_PORT_LABELING
 	struct smk_port_label *spp;
 
 	if (sk->sk_family == PF_INET6) {
@@ -2281,9 +2275,8 @@ static void smack_sk_free_security(struct sock *sk)
 		}
 		rcu_read_unlock();
 	}
-#endif
-	kfree(sk->sk_security);
 }
+#endif
 
 /**
 * smack_ipv4host_label - check host based restrictions
@@ -2396,7 +2389,7 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
  */
 static int smack_netlbl_add(struct sock *sk)
 {
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smack_known *skp = ssp->smk_out;
 	int rc;
 
@@ -2428,7 +2421,7 @@ static int smack_netlbl_add(struct sock *sk)
  */
 static void smack_netlbl_delete(struct sock *sk)
 {
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 
 	/*
 	 * Take the label off the socket if one is set.
@@ -2460,7 +2453,7 @@ static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
 	struct smack_known *skp;
 	int rc = 0;
 	struct smack_known *hkp;
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smk_audit_info ad;
 
 	rcu_read_lock();
@@ -2533,7 +2526,7 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
 {
 	struct sock *sk = sock->sk;
 	struct sockaddr_in6 *addr6;
-	struct socket_smack *ssp = sock->sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sock->sk);
 	struct smk_port_label *spp;
 	unsigned short port = 0;
 
@@ -2621,7 +2614,7 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
 				int act)
 {
 	struct smk_port_label *spp;
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smack_known *skp = NULL;
 	unsigned short port;
 	struct smack_known *object;
@@ -2715,7 +2708,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
 	if (sock == NULL || sock->sk == NULL)
 		return -EOPNOTSUPP;
 
-	ssp = sock->sk->sk_security;
+	ssp = smack_sock(sock->sk);
 
 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
 		ssp->smk_in = skp;
@@ -2763,7 +2756,7 @@ static int smack_socket_post_create(struct socket *sock, int family,
 	 * Sockets created by kernel threads receive web label.
 	 */
 	if (unlikely(current->flags & PF_KTHREAD)) {
-		ssp = sock->sk->sk_security;
+		ssp = smack_sock(sock->sk);
 		ssp->smk_in = &smack_known_web;
 		ssp->smk_out = &smack_known_web;
 	}
@@ -2788,8 +2781,8 @@ static int smack_socket_post_create(struct socket *sock, int family,
 static int smack_socket_socketpair(struct socket *socka,
 		                   struct socket *sockb)
 {
-	struct socket_smack *asp = socka->sk->sk_security;
-	struct socket_smack *bsp = sockb->sk->sk_security;
+	struct socket_smack *asp = smack_sock(socka->sk);
+	struct socket_smack *bsp = smack_sock(sockb->sk);
 
 	asp->smk_packet = bsp->smk_out;
 	bsp->smk_packet = asp->smk_out;
@@ -2852,7 +2845,7 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
 		if (__is_defined(SMACK_IPV6_SECMARK_LABELING))
 			rsp = smack_ipv6host_label(sip);
 		if (rsp != NULL) {
-			struct socket_smack *ssp = sock->sk->sk_security;
+			struct socket_smack *ssp = smack_sock(sock->sk);
 
 			rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
 					    SMK_CONNECTING);
@@ -3583,9 +3576,9 @@ static int smack_unix_stream_connect(struct sock *sock,
 {
 	struct smack_known *skp;
 	struct smack_known *okp;
-	struct socket_smack *ssp = sock->sk_security;
-	struct socket_smack *osp = other->sk_security;
-	struct socket_smack *nsp = newsk->sk_security;
+	struct socket_smack *ssp = smack_sock(sock);
+	struct socket_smack *osp = smack_sock(other);
+	struct socket_smack *nsp = smack_sock(newsk);
 	struct smk_audit_info ad;
 	int rc = 0;
 #ifdef CONFIG_AUDIT
@@ -3631,8 +3624,8 @@ static int smack_unix_stream_connect(struct sock *sock,
  */
 static int smack_unix_may_send(struct socket *sock, struct socket *other)
 {
-	struct socket_smack *ssp = sock->sk->sk_security;
-	struct socket_smack *osp = other->sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sock->sk);
+	struct socket_smack *osp = smack_sock(other->sk);
 	struct smk_audit_info ad;
 	int rc;
 
@@ -3669,7 +3662,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
 	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
 #endif
 #ifdef SMACK_IPV6_SECMARK_LABELING
-	struct socket_smack *ssp = sock->sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sock->sk);
 	struct smack_known *rsp;
 #endif
 	int rc = 0;
@@ -3881,7 +3874,7 @@ static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
 	netlbl_secattr_init(&secattr);
 
 	if (sk)
-		ssp = sk->sk_security;
+		ssp = smack_sock(sk);
 
 	if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
 		skp = smack_from_secattr(&secattr, ssp);
@@ -3903,7 +3896,7 @@ static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
  */
 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smack_known *skp = NULL;
 	int rc = 0;
 	struct smk_audit_info ad;
@@ -4007,7 +4000,7 @@ static int smack_socket_getpeersec_stream(struct socket *sock,
 	int slen = 1;
 	int rc = 0;
 
-	ssp = sock->sk->sk_security;
+	ssp = smack_sock(sock->sk);
 	if (ssp->smk_packet != NULL) {
 		rcp = ssp->smk_packet->smk_known;
 		slen = strlen(rcp) + 1;
@@ -4056,7 +4049,7 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 
 	switch (family) {
 	case PF_UNIX:
-		ssp = sock->sk->sk_security;
+		ssp = smack_sock(sock->sk);
 		s = ssp->smk_out->smk_secid;
 		break;
 	case PF_INET:
@@ -4105,7 +4098,7 @@ static void smack_sock_graft(struct sock *sk, struct socket *parent)
 	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
 		return;
 
-	ssp = sk->sk_security;
+	ssp = smack_sock(sk);
 	ssp->smk_in = skp;
 	ssp->smk_out = skp;
 	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
@@ -4125,7 +4118,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
 {
 	u16 family = sk->sk_family;
 	struct smack_known *skp;
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct sockaddr_in addr;
 	struct iphdr *hdr;
 	struct smack_known *hskp;
@@ -4211,7 +4204,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
 static void smack_inet_csk_clone(struct sock *sk,
 				 const struct request_sock *req)
 {
-	struct socket_smack *ssp = sk->sk_security;
+	struct socket_smack *ssp = smack_sock(sk);
 	struct smack_known *skp;
 
 	if (req->peer_secid != 0) {
@@ -4747,6 +4740,7 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
 	.lbs_inode = sizeof(struct inode_smack),
 	.lbs_ipc = sizeof(struct smack_known *),
 	.lbs_msg_msg = sizeof(struct smack_known *),
+	.lbs_sock = sizeof(struct socket_smack),
 	.lbs_superblock = sizeof(struct superblock_smack),
 };
 
@@ -4857,7 +4851,9 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
 	LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
 	LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
+#ifdef SMACK_IPV6_PORT_LABELING
 	LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
+#endif
 	LSM_HOOK_INIT(sock_graft, smack_sock_graft),
 	LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
 	LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c
index b945c1d3a743..bad71b7e648d 100644
--- a/security/smack/smack_netfilter.c
+++ b/security/smack/smack_netfilter.c
@@ -26,8 +26,8 @@ static unsigned int smack_ip_output(void *priv,
 	struct socket_smack *ssp;
 	struct smack_known *skp;
 
-	if (sk && sk->sk_security) {
-		ssp = sk->sk_security;
+	if (sk) {
+		ssp = smack_sock(sk);
 		skp = ssp->smk_out;
 		skb->secmark = skp->smk_secid;
 	}
-- 
2.36.1