NetLabel: SELinux cleanups
This patch does a lot of cleanup in the SELinux NetLabel support code. A summary of the changes include: * Use RCU locking for the NetLabel state variable in the skk_security_struct instead of using the inode_security_struct mutex. * Remove unnecessary parameters in selinux_netlbl_socket_post_create(). * Rename selinux_netlbl_sk_clone_security() to selinux_netlbl_sk_security_clone() to better fit the other NetLabel sk_security functions. * Improvements to selinux_netlbl_inode_permission() to help reduce the cost of the common case. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
parent
9bb5fd2b05
commit
9f2ad66509
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@ -3140,9 +3140,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
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if (sock->sk) {
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sksec = sock->sk->sk_security;
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sksec->sid = isec->sid;
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err = selinux_netlbl_socket_post_create(sock,
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family,
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isec->sid);
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err = selinux_netlbl_socket_post_create(sock);
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}
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return err;
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@ -3661,7 +3659,7 @@ static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
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newssec->sid = ssec->sid;
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newssec->peer_sid = ssec->peer_sid;
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selinux_netlbl_sk_clone_security(ssec, newssec);
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selinux_netlbl_sk_security_clone(ssec, newssec);
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}
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static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
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@ -3730,7 +3728,9 @@ static void selinux_inet_csk_clone(struct sock *newsk,
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So we will wait until sock_graft to do it, by which
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time it will have been created and available. */
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selinux_netlbl_sk_security_init(newsksec, req->rsk_ops->family);
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/* We don't need to take any sort of lock here as we are the only
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* thread with access to newsksec */
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selinux_netlbl_sk_security_reset(newsksec, req->rsk_ops->family);
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}
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static void selinux_inet_conn_established(struct sock *sk,
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@ -23,6 +23,7 @@
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#include <linux/fs.h>
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#include <linux/binfmts.h>
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#include <linux/in.h>
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#include <linux/spinlock.h>
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#include "flask.h"
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#include "avc.h"
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@ -108,6 +109,7 @@ struct sk_security_struct {
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NLBL_REQUIRE,
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NLBL_LABELED,
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} nlbl_state;
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spinlock_t nlbl_lock; /* protects nlbl_state */
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#endif
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};
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@ -38,9 +38,7 @@
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#ifdef CONFIG_NETLABEL
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void selinux_netlbl_cache_invalidate(void);
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int selinux_netlbl_socket_post_create(struct socket *sock,
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int sock_family,
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u32 sid);
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int selinux_netlbl_socket_post_create(struct socket *sock);
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void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock);
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u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid);
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int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
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@ -48,9 +46,11 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
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struct avc_audit_data *ad);
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u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock);
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u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb);
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void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
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int family);
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void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
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int family);
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void selinux_netlbl_sk_clone_security(struct sk_security_struct *ssec,
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void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
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struct sk_security_struct *newssec);
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int selinux_netlbl_inode_permission(struct inode *inode, int mask);
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int selinux_netlbl_socket_setsockopt(struct socket *sock,
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@ -62,9 +62,7 @@ static inline void selinux_netlbl_cache_invalidate(void)
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return;
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}
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static inline int selinux_netlbl_socket_post_create(struct socket *sock,
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int sock_family,
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u32 sid)
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static inline int selinux_netlbl_socket_post_create(struct socket *sock)
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{
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return 0;
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}
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@ -98,6 +96,13 @@ static inline u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb)
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return SECSID_NULL;
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}
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static inline void selinux_netlbl_sk_security_reset(
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struct sk_security_struct *ssec,
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int family)
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{
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return;
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}
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static inline void selinux_netlbl_sk_security_init(
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struct sk_security_struct *ssec,
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int family)
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@ -105,7 +110,7 @@ static inline void selinux_netlbl_sk_security_init(
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return;
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}
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static inline void selinux_netlbl_sk_clone_security(
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static inline void selinux_netlbl_sk_security_clone(
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struct sk_security_struct *ssec,
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struct sk_security_struct *newssec)
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{
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@ -33,6 +33,7 @@
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/errno.h>
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#include <linux/in.h>
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#include <linux/sched.h>
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@ -2435,7 +2436,9 @@ static int selinux_netlbl_skbuff_getsid(struct sk_buff *skb,
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*
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* Description:
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* Attempt to label a socket using the NetLabel mechanism using the given
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* SID. Returns zero values on success, negative values on failure.
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* SID. Returns zero values on success, negative values on failure. The
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* caller is responsibile for calling rcu_read_lock() before calling this
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* this function and rcu_read_unlock() after this function returns.
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*
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*/
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static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid)
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@ -2472,8 +2475,11 @@ static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid)
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secattr.flags |= NETLBL_SECATTR_MLS_CAT;
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rc = netlbl_socket_setattr(sock, &secattr);
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if (rc == 0)
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if (rc == 0) {
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spin_lock(&sksec->nlbl_lock);
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sksec->nlbl_state = NLBL_LABELED;
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spin_unlock(&sksec->nlbl_lock);
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}
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netlbl_socket_setsid_return:
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POLICY_RDUNLOCK;
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@ -2481,6 +2487,25 @@ netlbl_socket_setsid_return:
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return rc;
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}
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/**
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* selinux_netlbl_sk_security_reset - Reset the NetLabel fields
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* @ssec: the sk_security_struct
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* @family: the socket family
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*
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* Description:
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* Called when the NetLabel state of a sk_security_struct needs to be reset.
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* The caller is responsibile for all the NetLabel sk_security_struct locking.
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*
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*/
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void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec,
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int family)
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{
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if (family == PF_INET)
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ssec->nlbl_state = NLBL_REQUIRE;
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else
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ssec->nlbl_state = NLBL_UNSET;
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}
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/**
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* selinux_netlbl_sk_security_init - Setup the NetLabel fields
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* @ssec: the sk_security_struct
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@ -2494,14 +2519,13 @@ netlbl_socket_setsid_return:
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void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec,
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int family)
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{
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if (family == PF_INET)
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ssec->nlbl_state = NLBL_REQUIRE;
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else
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ssec->nlbl_state = NLBL_UNSET;
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/* No locking needed, we are the only one who has access to ssec */
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selinux_netlbl_sk_security_reset(ssec, family);
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spin_lock_init(&ssec->nlbl_lock);
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}
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/**
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* selinux_netlbl_sk_clone_security - Copy the NetLabel fields
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* selinux_netlbl_sk_security_clone - Copy the NetLabel fields
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* @ssec: the original sk_security_struct
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* @newssec: the cloned sk_security_struct
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*
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* @newssec.
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*
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*/
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void selinux_netlbl_sk_clone_security(struct sk_security_struct *ssec,
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void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec,
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struct sk_security_struct *newssec)
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{
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/* We don't need to take newssec->nlbl_lock because we are the only
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* thread with access to newssec, but we do need to take the RCU read
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* lock as other threads could have access to ssec */
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rcu_read_lock();
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selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family);
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newssec->sclass = ssec->sclass;
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if (ssec->nlbl_state != NLBL_UNSET)
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newssec->nlbl_state = NLBL_REQUIRE;
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else
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newssec->nlbl_state = NLBL_UNSET;
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rcu_read_unlock();
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}
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/**
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* selinux_netlbl_socket_post_create - Label a socket using NetLabel
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* @sock: the socket to label
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* @sock_family: the socket family
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* @sid: the SID to use
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*
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* Description:
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* Attempt to label a socket using the NetLabel mechanism using the given
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* SID. Returns zero values on success, negative values on failure.
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*
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*/
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int selinux_netlbl_socket_post_create(struct socket *sock,
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int sock_family,
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u32 sid)
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int selinux_netlbl_socket_post_create(struct socket *sock)
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{
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int rc = 0;
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struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
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struct sk_security_struct *sksec = sock->sk->sk_security;
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sksec->sclass = isec->sclass;
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if (sock_family != PF_INET)
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return 0;
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rcu_read_lock();
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if (sksec->nlbl_state == NLBL_REQUIRE)
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rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
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rcu_read_unlock();
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sksec->nlbl_state = NLBL_REQUIRE;
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return selinux_netlbl_socket_setsid(sock, sid);
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return rc;
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}
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/**
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sksec->sclass = isec->sclass;
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if (sk->sk_family != PF_INET)
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rcu_read_lock();
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if (sksec->nlbl_state != NLBL_REQUIRE) {
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rcu_read_unlock();
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return;
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}
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netlbl_secattr_init(&secattr);
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if (netlbl_sock_getattr(sk, &secattr) == 0 &&
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sksec->peer_sid = nlbl_peer_sid;
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netlbl_secattr_destroy(&secattr);
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sksec->nlbl_state = NLBL_REQUIRE;
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/* Try to set the NetLabel on the socket to save time later, if we fail
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* here we will pick up the pieces in later calls to
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* selinux_netlbl_inode_permission(). */
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selinux_netlbl_socket_setsid(sock, sksec->sid);
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rcu_read_unlock();
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}
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/**
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int selinux_netlbl_inode_permission(struct inode *inode, int mask)
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{
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int rc;
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struct inode_security_struct *isec;
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struct sk_security_struct *sksec;
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struct socket *sock;
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if (!S_ISSOCK(inode->i_mode))
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if (!S_ISSOCK(inode->i_mode) ||
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((mask & (MAY_WRITE | MAY_APPEND)) == 0))
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return 0;
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sock = SOCKET_I(inode);
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isec = inode->i_security;
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sksec = sock->sk->sk_security;
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mutex_lock(&isec->lock);
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if (unlikely(sksec->nlbl_state == NLBL_REQUIRE &&
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(mask & (MAY_WRITE | MAY_APPEND)))) {
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rcu_read_lock();
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if (sksec->nlbl_state != NLBL_REQUIRE) {
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rcu_read_unlock();
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return 0;
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}
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lock_sock(sock->sk);
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rc = selinux_netlbl_socket_setsid(sock, sksec->sid);
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release_sock(sock->sk);
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} else
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rc = 0;
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mutex_unlock(&isec->lock);
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rcu_read_unlock();
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return rc;
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}
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@ -2754,12 +2781,10 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock,
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int optname)
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{
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int rc = 0;
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struct inode *inode = SOCK_INODE(sock);
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struct sk_security_struct *sksec = sock->sk->sk_security;
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struct inode_security_struct *isec = inode->i_security;
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struct netlbl_lsm_secattr secattr;
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mutex_lock(&isec->lock);
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rcu_read_lock();
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if (level == IPPROTO_IP && optname == IP_OPTIONS &&
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sksec->nlbl_state == NLBL_LABELED) {
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netlbl_secattr_init(&secattr);
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rc = -EACCES;
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netlbl_secattr_destroy(&secattr);
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}
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mutex_unlock(&isec->lock);
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rcu_read_unlock();
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return rc;
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}
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