Commit message: selinux: Permit bounded transitions under NO_NEW_PRIVS or NOSUID.

If the callee SID is bounded by the caller SID, then allowing
the transition to occur poses no risk of privilege escalation and we can
therefore safely allow the transition to occur.  Add this exemption
for both the case where a transition was explicitly requested by the
application and the case where an automatic transition is defined in
policy.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Paul Moore <pmoore@redhat.com>
CVE: CVE-2014-3215
CWE: CWE-264
Vulnerability description: seunshare in policycoreutils 2.2.5 is owned by root with 4755 permissions, and executes programs in a way that changes the relationship between the setuid system call and the getresuid saved set-user-ID value, which makes it easier for local users to gain privileges by leveraging a program that mistakenly expected that it could permanently drop privileges.

Project: linux
File: hooks.c

static inline void flush_unauthorized_files(const struct cred *cred,
					    struct files_struct *files)
{
	struct file *file, *devnull = NULL;
	struct tty_struct *tty;
	int drop_tty = 0;
	unsigned n;

	tty = get_current_tty();
	if (tty) {
		spin_lock(&tty_files_lock);
		if (!list_empty(&tty->tty_files)) {
			struct tty_file_private *file_priv;

			/* Revalidate access to controlling tty.
			   Use file_path_has_perm on the tty path directly
			   rather than using file_has_perm, as this particular
			   open file may belong to another process and we are
			   only interested in the inode-based check here. */
			file_priv = list_first_entry(&tty->tty_files,
						struct tty_file_private, list);
			file = file_priv->file;
			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
				drop_tty = 1;
		}
		spin_unlock(&tty_files_lock);
		tty_kref_put(tty);
	}
	/* Reset controlling tty. */
	if (drop_tty)
		no_tty();

	/* Revalidate access to inherited open files. */
	n = iterate_fd(files, 0, match_file, cred);
	if (!n) /* none found? */
		return;

	devnull = dentry_open(&selinux_null, O_RDWR, cred);
	if (IS_ERR(devnull))
		devnull = NULL;
	/* replace all the matching ones with this */
	do {
		replace_fd(n - 1, devnull, 0);
	} while ((n = iterate_fd(files, n, match_file, cred)) != 0);
	if (devnull)
		fput(devnull);
}

Project: linux
File: hooks.c

static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
				       u16 family)
{
	int err;
	char *addrp;
	u32 peer_sid;
	struct common_audit_data ad;
	struct lsm_network_audit net = {0,};
	u8 secmark_active;
	u8 netlbl_active;
	u8 peerlbl_active;

	if (!selinux_policycap_netpeer)
		return NF_ACCEPT;

	secmark_active = selinux_secmark_enabled();
	netlbl_active = netlbl_enabled();
	peerlbl_active = selinux_peerlbl_enabled();
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;

	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
		return NF_DROP;

	ad.type = LSM_AUDIT_DATA_NET;
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
		return NF_DROP;

	if (peerlbl_active) {
		err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
					       peer_sid, &ad);
		if (err) {
			selinux_netlbl_err(skb, err, 1);
			return NF_DROP;
		}
	}

	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
			return NF_DROP;

	if (netlbl_active)
		/* we do this in the FORWARD path and not the POST_ROUTING
		 * path because we want to make sure we apply the necessary
		 * labeling before IPsec is applied so we can leverage AH
		 * protection */
		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
			return NF_DROP;

	return NF_ACCEPT;
}

Project: linux
File: hooks.c

static unsigned int selinux_ipv4_output(const struct nf_hook_ops *ops,
					struct sk_buff *skb,
					const struct net_device *in,
					const struct net_device *out,
					int (*okfn)(struct sk_buff *))
{
	return selinux_ip_output(skb, PF_INET);
}

Project: linux
File: hooks.c

static unsigned int selinux_ipv6_postroute(const struct nf_hook_ops *ops,
					   struct sk_buff *skb,
					   const struct net_device *in,
					   const struct net_device *out,
					   int (*okfn)(struct sk_buff *))
{
	return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
}

Project: linux
File: hooks.c

static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
					const void *value, size_t size,
					int flags)
{
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	u32 newsid;
	int rc;

	if (strcmp(name, XATTR_NAME_SELINUX)) {
		/* Not an attribute we recognize, so nothing to do. */
		return;
	}

	rc = security_context_to_sid_force(value, size, &newsid);
	if (rc) {
		printk(KERN_ERR "SELinux:  unable to map context to SID"
		       "for (%s, %lu), rc=%d\n",
		       inode->i_sb->s_id, inode->i_ino, -rc);
		return;
	}

	isec->sclass = inode_mode_to_security_class(inode->i_mode);
	isec->sid = newsid;
	isec->initialized = 1;

	return;
}

Project: linux
File: hooks.c

static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
{
	int err;

	err = cap_netlink_send(sk, skb);
	if (err)
		return err;

	return selinux_nlmsg_perm(sk, skb);
}

Project: linux
File: hooks.c

static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
	int error;

	error = current_has_perm(target, PROCESS__GETCAP);
	if (error)
		return error;

	return cap_capget(target, effective, inheritable, permitted);
}

Project: linux
File: hooks.c

static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
			     char **_addrp, int src, u8 *proto)
{
	char *addrp;
	int ret;

	switch (ad->u.net->family) {
	case PF_INET:
		ret = selinux_parse_skb_ipv4(skb, ad, proto);
		if (ret)
			goto parse_error;
		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
				       &ad->u.net->v4info.daddr);
		goto okay;

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	case PF_INET6:
		ret = selinux_parse_skb_ipv6(skb, ad, proto);
		if (ret)
			goto parse_error;
		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
				       &ad->u.net->v6info.daddr);
		goto okay;
#endif	/* IPV6 */
	default:
		addrp = NULL;
		goto okay;
	}

parse_error:
	printk(KERN_WARNING
	       "SELinux: failure in selinux_parse_skb(),"
	       " unable to parse packet\n");
	return ret;

okay:
	if (_addrp)
		*_addrp = addrp;
	return 0;
}

Project: linux
File: hooks.c

static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
{
	int err;
	struct inode_security_struct *isec;
	struct inode_security_struct *newisec;

	err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
	if (err)
		return err;

	newisec = SOCK_INODE(newsock)->i_security;

	isec = SOCK_INODE(sock)->i_security;
	newisec->sclass = isec->sclass;
	newisec->sid = isec->sid;
	newisec->initialized = 1;

	return 0;
}

Project: linux
File: hooks.c

static int selinux_cmp_sb_context(const struct super_block *oldsb,
				    const struct super_block *newsb)
{
	struct superblock_security_struct *old = oldsb->s_security;
	struct superblock_security_struct *new = newsb->s_security;
	char oldflags = old->flags & SE_MNTMASK;
	char newflags = new->flags & SE_MNTMASK;

	if (oldflags != newflags)
		goto mismatch;
	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
		goto mismatch;
	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
		goto mismatch;
	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
		goto mismatch;
	if (oldflags & ROOTCONTEXT_MNT) {
		struct inode_security_struct *oldroot = oldsb->s_root->d_inode->i_security;
		struct inode_security_struct *newroot = newsb->s_root->d_inode->i_security;
		if (oldroot->sid != newroot->sid)
			goto mismatch;
	}
	return 0;
mismatch:
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, "
			    "different security settings for (dev %s, "
			    "type %s)\n", newsb->s_id, newsb->s_type->name);
	return -EBUSY;
}

Project: linux
File: hooks.c

static int selinux_file_mprotect(struct vm_area_struct *vma,
				 unsigned long reqprot,
				 unsigned long prot)
{
	const struct cred *cred = current_cred();

	if (selinux_checkreqprot)
		prot = reqprot;

	if (default_noexec &&
	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
		int rc = 0;
		if (vma->vm_start >= vma->vm_mm->start_brk &&
		    vma->vm_end <= vma->vm_mm->brk) {
			rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
		} else if (!vma->vm_file &&
			   vma->vm_start <= vma->vm_mm->start_stack &&
			   vma->vm_end >= vma->vm_mm->start_stack) {
			rc = current_has_perm(current, PROCESS__EXECSTACK);
		} else if (vma->vm_file && vma->anon_vma) {
			/*
			 * We are making executable a file mapping that has
			 * had some COW done. Since pages might have been
			 * written, check ability to execute the possibly
			 * modified content.  This typically should only
			 * occur for text relocations.
			 */
			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
		}
		if (rc)
			return rc;
	}

	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
}

Project: linux
File: hooks.c

static int selinux_file_open(struct file *file, const struct cred *cred)
{
	struct file_security_struct *fsec;
	struct inode_security_struct *isec;

	fsec = file->f_security;
	isec = file_inode(file)->i_security;
	/*
	 * Save inode label and policy sequence number
	 * at open-time so that selinux_file_permission
	 * can determine whether revalidation is necessary.
	 * Task label is already saved in the file security
	 * struct as its SID.
	 */
	fsec->isid = isec->sid;
	fsec->pseqno = avc_policy_seqno();
	/*
	 * Since the inode label or policy seqno may have changed
	 * between the selinux_inode_permission check and the saving
	 * of state above, recheck that access is still permitted.
	 * Otherwise, access might never be revalidated against the
	 * new inode label or new policy.
	 * This check is not redundant - do not remove.
	 */
	return file_path_has_perm(cred, file, open_file_to_av(file));
}

Project: linux
File: hooks.c

static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
{
	struct inode_security_struct *isec = inode->i_security;
	*secid = isec->sid;
}

Project: linux
File: hooks.c

static void inode_free_security(struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec = inode->i_sb->s_security;

	spin_lock(&sbsec->isec_lock);
	if (!list_empty(&isec->list))
		list_del_init(&isec->list);
	spin_unlock(&sbsec->isec_lock);

	/*
	 * The inode may still be referenced in a path walk and
	 * a call to selinux_inode_permission() can be made
	 * after inode_free_security() is called. Ideally, the VFS
	 * wouldn't do this, but fixing that is a much harder
	 * job. For now, simply free the i_security via RCU, and
	 * leave the current inode->i_security pointer intact.
	 * The inode will be freed after the RCU grace period too.
	 */
	call_rcu(&isec->rcu, inode_free_rcu);
}

Project: linux
File: hooks.c

static int selinux_bprm_secureexec(struct linux_binprm *bprm)
{
	const struct task_security_struct *tsec = current_security();
	u32 sid, osid;
	int atsecure = 0;

	sid = tsec->sid;
	osid = tsec->osid;

	if (osid != sid) {
		/* Enable secure mode for SIDs transitions unless
		   the noatsecure permission is granted between
		   the two SIDs, i.e. ahp returns 0. */
		atsecure = avc_has_perm(osid, sid,
					SECCLASS_PROCESS,
					PROCESS__NOATSECURE, NULL);
	}

	return (atsecure || cap_bprm_secureexec(bprm));
}

Project: linux
File: hooks.c

static int selinux_task_setnice(struct task_struct *p, int nice)
{
	int rc;

	rc = cap_task_setnice(p, nice);
	if (rc)
		return rc;

	return current_has_perm(p, PROCESS__SETSCHED);
}

Project: linux
File: hooks.c

static int file_alloc_security(struct file *file)
{
	struct file_security_struct *fsec;
	u32 sid = current_sid();

	fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
	if (!fsec)
		return -ENOMEM;

	fsec->sid = sid;
	fsec->fown_sid = sid;
	file->f_security = fsec;

	return 0;
}

Project: linux
File: hooks.c

static int selinux_capset(struct cred *new, const struct cred *old,
			  const kernel_cap_t *effective,
			  const kernel_cap_t *inheritable,
			  const kernel_cap_t *permitted)
{
	int error;

	error = cap_capset(new, old,
				      effective, inheritable, permitted);
	if (error)
		return error;

	return cred_has_perm(old, new, PROCESS__SETCAP);
}

Project: linux
File: hooks.c

static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops,
					   struct sk_buff *skb,
					   const struct net_device *in,
					   const struct net_device *out,
					   int (*okfn)(struct sk_buff *))
{
	return selinux_ip_postroute(skb, out->ifindex, PF_INET);
}

Project: linux
File: hooks.c

static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops,
					 struct sk_buff *skb,
					 const struct net_device *in,
					 const struct net_device *out,
					 int (*okfn)(struct sk_buff *))
{
	return selinux_ip_forward(skb, in->ifindex, PF_INET6);
}

Project: linux
File: hooks.c

static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
						int ifindex,
						u16 family)
{
	struct sock *sk = skb->sk;
	struct sk_security_struct *sksec;
	struct common_audit_data ad;
	struct lsm_network_audit net = {0,};
	char *addrp;
	u8 proto;

	if (sk == NULL)
		return NF_ACCEPT;
	sksec = sk->sk_security;

	ad.type = LSM_AUDIT_DATA_NET;
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
		return NF_DROP;

	if (selinux_secmark_enabled())
		if (avc_has_perm(sksec->sid, skb->secmark,
				 SECCLASS_PACKET, PACKET__SEND, &ad))
			return NF_DROP_ERR(-ECONNREFUSED);

	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
		return NF_DROP_ERR(-ECONNREFUSED);

	return NF_ACCEPT;
}

Project: linux
File: hooks.c

static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
					struct super_block *newsb)
{
	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
	struct superblock_security_struct *newsbsec = newsb->s_security;

	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);

	/*
	 * if the parent was able to be mounted it clearly had no special lsm
	 * mount options.  thus we can safely deal with this superblock later
	 */
	if (!ss_initialized)
		return 0;

	/* how can we clone if the old one wasn't set up?? */
	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));

	/* if fs is reusing a sb, make sure that the contexts match */
	if (newsbsec->flags & SE_SBINITIALIZED)
		return selinux_cmp_sb_context(oldsb, newsb);

	mutex_lock(&newsbsec->lock);

	newsbsec->flags = oldsbsec->flags;

	newsbsec->sid = oldsbsec->sid;
	newsbsec->def_sid = oldsbsec->def_sid;
	newsbsec->behavior = oldsbsec->behavior;

	if (set_context) {
		u32 sid = oldsbsec->mntpoint_sid;

		if (!set_fscontext)
			newsbsec->sid = sid;
		if (!set_rootcontext) {
			struct inode *newinode = newsb->s_root->d_inode;
			struct inode_security_struct *newisec = newinode->i_security;
			newisec->sid = sid;
		}
		newsbsec->mntpoint_sid = sid;
	}
	if (set_rootcontext) {
		const struct inode *oldinode = oldsb->s_root->d_inode;
		const struct inode_security_struct *oldisec = oldinode->i_security;
		struct inode *newinode = newsb->s_root->d_inode;
		struct inode_security_struct *newisec = newinode->i_security;

		newisec->sid = oldisec->sid;
	}

	sb_finish_set_opts(newsb);
	mutex_unlock(&newsbsec->lock);
	return 0;
}

Project: linux
File: hooks.c

static int selinux_is_sblabel_mnt(struct super_block *sb)
{
	struct superblock_security_struct *sbsec = sb->s_security;

	if (sbsec->behavior == SECURITY_FS_USE_XATTR ||
	    sbsec->behavior == SECURITY_FS_USE_TRANS ||
	    sbsec->behavior == SECURITY_FS_USE_TASK)
		return 1;

	/* Special handling for sysfs. Is genfs but also has setxattr handler*/
	if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
		return 1;

	/*
	 * Special handling for rootfs. Is genfs but supports
	 * setting SELinux context on in-core inodes.
	 */
	if (strncmp(sb->s_type->name, "rootfs", sizeof("rootfs")) == 0)
		return 1;

	return 0;
}

Project: linux
File: hooks.c

static int __init selinux_nf_ip_init(void)
{
	int err = 0;

	if (!selinux_enabled)
		goto out;

	printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");

	err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
	if (err)
		panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
	if (err)
		panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
#endif	/* IPV6 */

out:
	return err;
}

Project: linux
File: hooks.c

static inline int dentry_has_perm(const struct cred *cred,
				  struct dentry *dentry,
				  u32 av)
{
	struct inode *inode = dentry->d_inode;
	struct common_audit_data ad;

	ad.type = LSM_AUDIT_DATA_DENTRY;
	ad.u.dentry = dentry;
	return inode_has_perm(cred, inode, av, &ad);
}

Project: linux
File: hooks.c

static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
{
	const struct cred *cred = current_cred();

	return dentry_has_perm(cred, dentry, FILE__READ);
}

Project: linux
File: hooks.c

static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
	const struct task_security_struct *tsec = current_security();
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
	u32 sid, newsid;
	struct common_audit_data ad;
	int rc;

	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

	sid = tsec->sid;
	newsid = tsec->create_sid;

	ad.type = LSM_AUDIT_DATA_DENTRY;
	ad.u.dentry = dentry;

	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
			  DIR__ADD_NAME | DIR__SEARCH,
			  &ad);
	if (rc)
		return rc;

	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
		rc = security_transition_sid(sid, dsec->sid, tclass,
					     &dentry->d_name, &newsid);
		if (rc)
			return rc;
	}

	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
	if (rc)
		return rc;

	return avc_has_perm(newsid, sbsec->sid,
			    SECCLASS_FILESYSTEM,
			    FILESYSTEM__ASSOCIATE, &ad);
}

Project: linux
File: hooks.c

static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
{
	int rc, cap_sys_admin = 0;

	rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
			     SECURITY_CAP_NOAUDIT);
	if (rc == 0)
		cap_sys_admin = 1;

	return __vm_enough_memory(mm, pages, cap_sys_admin);
}

Project: linux
File: hooks.c

static int selinux_inode_permission(struct inode *inode, int mask)
{
	const struct cred *cred = current_cred();
	u32 perms;
	bool from_access;
	unsigned flags = mask & MAY_NOT_BLOCK;
	struct inode_security_struct *isec;
	u32 sid;
	struct av_decision avd;
	int rc, rc2;
	u32 audited, denied;

	from_access = mask & MAY_ACCESS;
	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);

	/* No permission to check.  Existence test. */
	if (!mask)
		return 0;

	validate_creds(cred);

	if (unlikely(IS_PRIVATE(inode)))
		return 0;

	perms = file_mask_to_av(inode->i_mode, mask);

	sid = cred_sid(cred);
	isec = inode->i_security;

	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
	audited = avc_audit_required(perms, &avd, rc,
				     from_access ? FILE__AUDIT_ACCESS : 0,
				     &denied);
	if (likely(!audited))
		return rc;

	rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
	if (rc2)
		return rc2;
	return rc;
}

Project: linux
File: hooks.c

static int selinux_ptrace_traceme(struct task_struct *parent)
{
	int rc;

	rc = cap_ptrace_traceme(parent);
	if (rc)
		return rc;

	return task_has_perm(parent, current, PROCESS__PTRACE);
}

Project: linux
File: hooks.c

static int selinux_get_mnt_opts(const struct super_block *sb,
				struct security_mnt_opts *opts)
{
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	char *context = NULL;
	u32 len;
	char tmp;

	security_init_mnt_opts(opts);

	if (!(sbsec->flags & SE_SBINITIALIZED))
		return -EINVAL;

	if (!ss_initialized)
		return -EINVAL;

	/* make sure we always check enough bits to cover the mask */
	BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));

	tmp = sbsec->flags & SE_MNTMASK;
	/* count the number of mount options for this sb */
	for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
		if (tmp & 0x01)
			opts->num_mnt_opts++;
		tmp >>= 1;
	}
	/* Check if the Label support flag is set */
	if (sbsec->flags & SBLABEL_MNT)
		opts->num_mnt_opts++;

	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts) {
		rc = -ENOMEM;
		goto out_free;
	}

	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
		rc = -ENOMEM;
		goto out_free;
	}

	i = 0;
	if (sbsec->flags & FSCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->sid, &context, &len);
		if (rc)
			goto out_free;
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
	}
	if (sbsec->flags & CONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
		if (rc)
			goto out_free;
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
	}
	if (sbsec->flags & DEFCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
		if (rc)
			goto out_free;
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
	}
	if (sbsec->flags & ROOTCONTEXT_MNT) {
		struct inode *root = sbsec->sb->s_root->d_inode;
		struct inode_security_struct *isec = root->i_security;

		rc = security_sid_to_context(isec->sid, &context, &len);
		if (rc)
			goto out_free;
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
	}
	if (sbsec->flags & SBLABEL_MNT) {
		opts->mnt_opts[i] = NULL;
		opts->mnt_opts_flags[i++] = SBLABEL_MNT;
	}

	BUG_ON(i != opts->num_mnt_opts);

	return 0;

out_free:
	security_free_mnt_opts(opts);
	return rc;
}

Project: linux
File: hooks.c

static __init int selinux_init(void)
{
	if (!security_module_enable(&selinux_ops)) {
		selinux_enabled = 0;
		return 0;
	}

	if (!selinux_enabled) {
		printk(KERN_INFO "SELinux:  Disabled at boot.\n");
		return 0;
	}

	printk(KERN_INFO "SELinux:  Initializing.\n");

	/* Set the security state for the initial task. */
	cred_init_security();

	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);

	sel_inode_cache = kmem_cache_create("selinux_inode_security",
					    sizeof(struct inode_security_struct),
					    0, SLAB_PANIC, NULL);
	avc_init();

	if (register_security(&selinux_ops))
		panic("SELinux: Unable to register with kernel.\n");

	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
		panic("SELinux: Unable to register AVC netcache callback\n");

	if (selinux_enforcing)
		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
	else
		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");

	return 0;
}

Project: linux
File: hooks.c

static inline int may_rename(struct inode *old_dir,
			     struct dentry *old_dentry,
			     struct inode *new_dir,
			     struct dentry *new_dentry)
{
	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
	struct common_audit_data ad;
	u32 sid = current_sid();
	u32 av;
	int old_is_dir, new_is_dir;
	int rc;

	old_dsec = old_dir->i_security;
	old_isec = old_dentry->d_inode->i_security;
	old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
	new_dsec = new_dir->i_security;

	ad.type = LSM_AUDIT_DATA_DENTRY;

	ad.u.dentry = old_dentry;
	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
	rc = avc_has_perm(sid, old_isec->sid,
			  old_isec->sclass, FILE__RENAME, &ad);
	if (rc)
		return rc;
	if (old_is_dir && new_dir != old_dir) {
		rc = avc_has_perm(sid, old_isec->sid,
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

	ad.u.dentry = new_dentry;
	av = DIR__ADD_NAME | DIR__SEARCH;
	if (new_dentry->d_inode)
		av |= DIR__REMOVE_NAME;
	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
	if (rc)
		return rc;
	if (new_dentry->d_inode) {
		new_isec = new_dentry->d_inode->i_security;
		new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
		rc = avc_has_perm(sid, new_isec->sid,
				  new_isec->sclass,
				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
		if (rc)
			return rc;
	}

	return 0;
}

Project: linux
File: hooks.c

static int selinux_file_set_fowner(struct file *file)
{
	struct file_security_struct *fsec;

	fsec = file->f_security;
	fsec->fown_sid = current_sid();

	return 0;
}

Project: linux
File: hooks.c

static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
				       const struct qstr *qstr,
				       const char **name,
				       void **value, size_t *len)
{
	const struct task_security_struct *tsec = current_security();
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
	u32 sid, newsid, clen;
	int rc;
	char *context;

	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

	sid = tsec->sid;
	newsid = tsec->create_sid;

	if ((sbsec->flags & SE_SBINITIALIZED) &&
	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
		newsid = sbsec->mntpoint_sid;
	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
		rc = security_transition_sid(sid, dsec->sid,
					     inode_mode_to_security_class(inode->i_mode),
					     qstr, &newsid);
		if (rc) {
			printk(KERN_WARNING "%s:  "
			       "security_transition_sid failed, rc=%d (dev=%s "
			       "ino=%ld)\n",
			       __func__,
			       -rc, inode->i_sb->s_id, inode->i_ino);
			return rc;
		}
	}

	/* Possibly defer initialization to selinux_complete_init. */
	if (sbsec->flags & SE_SBINITIALIZED) {
		struct inode_security_struct *isec = inode->i_security;
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		isec->sid = newsid;
		isec->initialized = 1;
	}

	if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
		return -EOPNOTSUPP;

	if (name)
		*name = XATTR_SELINUX_SUFFIX;

	if (value && len) {
		rc = security_sid_to_context_force(newsid, &context, &clen);
		if (rc)
			return rc;
		*value = context;
		*len = clen;
	}

	return 0;
}

Project: linux
File: hooks.c

static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
				    u32 peer_sid,
				    struct common_audit_data *ad)
{
	int err;
	u32 if_sid;
	u32 node_sid;

	err = sel_netif_sid(ifindex, &if_sid);
	if (err)
		return err;
	err = avc_has_perm(peer_sid, if_sid,
			   SECCLASS_NETIF, NETIF__INGRESS, ad);
	if (err)
		return err;

	err = sel_netnode_sid(addrp, family, &node_sid);
	if (err)
		return err;
	return avc_has_perm(peer_sid, node_sid,
			    SECCLASS_NODE, NODE__RECVFROM, ad);
}

Project: linux
File: hooks.c

static int file_has_perm(const struct cred *cred,
			 struct file *file,
			 u32 av)
{
	struct file_security_struct *fsec = file->f_security;
	struct inode *inode = file_inode(file);
	struct common_audit_data ad;
	u32 sid = cred_sid(cred);
	int rc;

	ad.type = LSM_AUDIT_DATA_PATH;
	ad.u.path = file->f_path;

	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid,
				  SECCLASS_FD,
				  FD__USE,
				  &ad);
		if (rc)
			goto out;
	}

	/* av is zero if only checking access to the descriptor. */
	rc = 0;
	if (av)
		rc = inode_has_perm(cred, inode, av, &ad);

out:
	return rc;
}

Project: linux
File: hooks.c

static int selinux_dentry_init_security(struct dentry *dentry, int mode,
					struct qstr *name, void **ctx,
					u32 *ctxlen)
{
	const struct cred *cred = current_cred();
	struct task_security_struct *tsec;
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
	struct inode *dir = dentry->d_parent->d_inode;
	u32 newsid;
	int rc;

	tsec = cred->security;
	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
		newsid = tsec->create_sid;
	} else {
		rc = security_transition_sid(tsec->sid, dsec->sid,
					     inode_mode_to_security_class(mode),
					     name,
					     &newsid);
		if (rc) {
			printk(KERN_WARNING
				"%s: security_transition_sid failed, rc=%d\n",
			       __func__, -rc);
			return rc;
		}
	}

	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
}

Project: linux
File: hooks.c

static void selinux_skb_owned_by(struct sk_buff *skb, struct sock *sk)
{
	skb_set_owner_w(skb, sk);
}

Project: linux
File: hooks.c

static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
	const struct cred *cred = current_cred();
	int rc = 0;

	if (default_noexec &&
	    (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
		/*
		 * We are making executable an anonymous mapping or a
		 * private file mapping that will also be writable.
		 * This has an additional check.
		 */
		rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
		if (rc)
			goto error;
	}

	if (file) {
		/* read access is always possible with a mapping */
		u32 av = FILE__READ;

		/* write access only matters if the mapping is shared */
		if (shared && (prot & PROT_WRITE))
			av |= FILE__WRITE;

		if (prot & PROT_EXEC)
			av |= FILE__EXECUTE;

		return file_has_perm(cred, file, av);
	}

error:
	return rc;
}

Project: linux
File: hooks.c

static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
{
	struct superblock_security_struct *sbsec = NULL;
	struct inode_security_struct *isec = inode->i_security;
	u32 sid;
	struct dentry *dentry;
#define INITCONTEXTLEN 255
	char *context = NULL;
	unsigned len = 0;
	int rc = 0;

	if (isec->initialized)
		goto out;

	mutex_lock(&isec->lock);
	if (isec->initialized)
		goto out_unlock;

	sbsec = inode->i_sb->s_security;
	if (!(sbsec->flags & SE_SBINITIALIZED)) {
		/* Defer initialization until selinux_complete_init,
		   after the initial policy is loaded and the security
		   server is ready to handle calls. */
		spin_lock(&sbsec->isec_lock);
		if (list_empty(&isec->list))
			list_add(&isec->list, &sbsec->isec_head);
		spin_unlock(&sbsec->isec_lock);
		goto out_unlock;
	}

	switch (sbsec->behavior) {
	case SECURITY_FS_USE_NATIVE:
		break;
	case SECURITY_FS_USE_XATTR:
		if (!inode->i_op->getxattr) {
			isec->sid = sbsec->def_sid;
			break;
		}

		/* Need a dentry, since the xattr API requires one.
		   Life would be simpler if we could just pass the inode. */
		if (opt_dentry) {
			/* Called from d_instantiate or d_splice_alias. */
			dentry = dget(opt_dentry);
		} else {
			/* Called from selinux_complete_init, try to find a dentry. */
			dentry = d_find_alias(inode);
		}
		if (!dentry) {
			/*
			 * this is can be hit on boot when a file is accessed
			 * before the policy is loaded.  When we load policy we
			 * may find inodes that have no dentry on the
			 * sbsec->isec_head list.  No reason to complain as these
			 * will get fixed up the next time we go through
			 * inode_doinit with a dentry, before these inodes could
			 * be used again by userspace.
			 */
			goto out_unlock;
		}

		len = INITCONTEXTLEN;
		context = kmalloc(len+1, GFP_NOFS);
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
			goto out_unlock;
		}
		context[len] = '\0';
		rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
					   context, len);
		if (rc == -ERANGE) {
			kfree(context);

			/* Need a larger buffer.  Query for the right size. */
			rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
						   NULL, 0);
			if (rc < 0) {
				dput(dentry);
				goto out_unlock;
			}
			len = rc;
			context = kmalloc(len+1, GFP_NOFS);
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
				goto out_unlock;
			}
			context[len] = '\0';
			rc = inode->i_op->getxattr(dentry,
						   XATTR_NAME_SELINUX,
						   context, len);
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
				       "%d for dev=%s ino=%ld\n", __func__,
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
				goto out_unlock;
			}
			/* Map ENODATA to the default file SID */
			sid = sbsec->def_sid;
			rc = 0;
		} else {
			rc = security_context_to_sid_default(context, rc, &sid,
							     sbsec->def_sid,
							     GFP_NOFS);
			if (rc) {
				char *dev = inode->i_sb->s_id;
				unsigned long ino = inode->i_ino;

				if (rc == -EINVAL) {
					if (printk_ratelimit())
						printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
							"context=%s.  This indicates you may need to relabel the inode or the "
							"filesystem in question.\n", ino, dev, context);
				} else {
					printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
					       "returned %d for dev=%s ino=%ld\n",
					       __func__, context, -rc, dev, ino);
				}
				kfree(context);
				/* Leave with the unlabeled SID */
				rc = 0;
				break;
			}
		}
		kfree(context);
		isec->sid = sid;
		break;
	case SECURITY_FS_USE_TASK:
		isec->sid = isec->task_sid;
		break;
	case SECURITY_FS_USE_TRANS:
		/* Default to the fs SID. */
		isec->sid = sbsec->sid;

		/* Try to obtain a transition SID. */
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		rc = security_transition_sid(isec->task_sid, sbsec->sid,
					     isec->sclass, NULL, &sid);
		if (rc)
			goto out_unlock;
		isec->sid = sid;
		break;
	case SECURITY_FS_USE_MNTPOINT:
		isec->sid = sbsec->mntpoint_sid;
		break;
	default:
		/* Default to the fs superblock SID. */
		isec->sid = sbsec->sid;

		if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
			/* We must have a dentry to determine the label on
			 * procfs inodes */
			if (opt_dentry)
				/* Called from d_instantiate or
				 * d_splice_alias. */
				dentry = dget(opt_dentry);
			else
				/* Called from selinux_complete_init, try to
				 * find a dentry. */
				dentry = d_find_alias(inode);
			/*
			 * This can be hit on boot when a file is accessed
			 * before the policy is loaded.  When we load policy we
			 * may find inodes that have no dentry on the
			 * sbsec->isec_head list.  No reason to complain as
			 * these will get fixed up the next time we go through
			 * inode_doinit() with a dentry, before these inodes
			 * could be used again by userspace.
			 */
			if (!dentry)
				goto out_unlock;
			isec->sclass = inode_mode_to_security_class(inode->i_mode);
			rc = selinux_proc_get_sid(dentry, isec->sclass, &sid);
			dput(dentry);
			if (rc)
				goto out_unlock;
			isec->sid = sid;
		}
		break;
	}

	isec->initialized = 1;

out_unlock:
	mutex_unlock(&isec->lock);
out:
	if (isec->sclass == SECCLASS_FILE)
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
	return rc;
}

Project: linux
File: hooks.c

static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
{
	const struct task_security_struct *tsec = current_security();
	struct itimerval itimer;
	u32 osid, sid;
	int rc, i;

	osid = tsec->osid;
	sid = tsec->sid;

	if (sid == osid)
		return;

	/* Check whether the new SID can inherit signal state from the old SID.
	 * If not, clear itimers to avoid subsequent signal generation and
	 * flush and unblock signals.
	 *
	 * This must occur _after_ the task SID has been updated so that any
	 * kill done after the flush will be checked against the new SID.
	 */
	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
	if (rc) {
		memset(&itimer, 0, sizeof itimer);
		for (i = 0; i < 3; i++)
			do_setitimer(i, &itimer, NULL);
		spin_lock_irq(&current->sighand->siglock);
		if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
			__flush_signals(current);
			flush_signal_handlers(current, 1);
			sigemptyset(&current->blocked);
		}
		spin_unlock_irq(&current->sighand->siglock);
	}

	/* Wake up the parent if it is waiting so that it can recheck
	 * wait permission to the new task SID. */
	read_lock(&tasklist_lock);
	__wake_up_parent(current, current->real_parent);
	read_unlock(&tasklist_lock);
}

Project: linux
File: hooks.c

static int selinux_sb_remount(struct super_block *sb, void *data)
{
	int rc, i, *flags;
	struct security_mnt_opts opts;
	char *secdata, **mount_options;
	struct superblock_security_struct *sbsec = sb->s_security;

	if (!(sbsec->flags & SE_SBINITIALIZED))
		return 0;

	if (!data)
		return 0;

	if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
		return 0;

	security_init_mnt_opts(&opts);
	secdata = alloc_secdata();
	if (!secdata)
		return -ENOMEM;
	rc = selinux_sb_copy_data(data, secdata);
	if (rc)
		goto out_free_secdata;

	rc = selinux_parse_opts_str(secdata, &opts);
	if (rc)
		goto out_free_secdata;

	mount_options = opts.mnt_opts;
	flags = opts.mnt_opts_flags;

	for (i = 0; i < opts.num_mnt_opts; i++) {
		u32 sid;
		size_t len;

		if (flags[i] == SBLABEL_MNT)
			continue;
		len = strlen(mount_options[i]);
		rc = security_context_to_sid(mount_options[i], len, &sid,
					     GFP_KERNEL);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, sb->s_type->name, rc);
			goto out_free_opts;
		}
		rc = -EINVAL;
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
				goto out_bad_option;
			break;
		case CONTEXT_MNT:
			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
				goto out_bad_option;
			break;
		case ROOTCONTEXT_MNT: {
			struct inode_security_struct *root_isec;
			root_isec = sb->s_root->d_inode->i_security;

			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
				goto out_bad_option;
			break;
		}
		case DEFCONTEXT_MNT:
			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
				goto out_bad_option;
			break;
		default:
			goto out_free_opts;
		}
	}

	rc = 0;
out_free_opts:
	security_free_mnt_opts(&opts);
out_free_secdata:
	free_secdata(secdata);
	return rc;
out_bad_option:
	printk(KERN_WARNING "SELinux: unable to change security options "
	       "during remount (dev %s, type=%s)\n", sb->s_id,
	       sb->s_type->name);
	goto out_free_opts;
}

Project: linux
File: hooks.c

static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
			   int cap, int audit)
{
	int rc;

	rc = cap_capable(cred, ns, cap, audit);
	if (rc)
		return rc;

	return cred_has_capability(cred, cap, audit);
}

Project: linux
File: hooks.c

static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
{
	struct task_security_struct *new_tsec;
	struct rlimit *rlim, *initrlim;
	int rc, i;

	new_tsec = bprm->cred->security;
	if (new_tsec->sid == new_tsec->osid)
		return;

	/* Close files for which the new task SID is not authorized. */
	flush_unauthorized_files(bprm->cred, current->files);

	/* Always clear parent death signal on SID transitions. */
	current->pdeath_signal = 0;

	/* Check whether the new SID can inherit resource limits from the old
	 * SID.  If not, reset all soft limits to the lower of the current
	 * task's hard limit and the init task's soft limit.
	 *
	 * Note that the setting of hard limits (even to lower them) can be
	 * controlled by the setrlimit check.  The inclusion of the init task's
	 * soft limit into the computation is to avoid resetting soft limits
	 * higher than the default soft limit for cases where the default is
	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
	 */
	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
			  PROCESS__RLIMITINH, NULL);
	if (rc) {
		/* protect against do_prlimit() */
		task_lock(current);
		for (i = 0; i < RLIM_NLIMITS; i++) {
			rlim = current->signal->rlim + i;
			initrlim = init_task.signal->rlim + i;
			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
		}
		task_unlock(current);
		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
	}
}

Project: linux
File: hooks.c

static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
	int rc;

	rc = cap_task_setioprio(p, ioprio);
	if (rc)
		return rc;

	return current_has_perm(p, PROCESS__SETSCHED);
}

Project: linux
File: hooks.c

static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
					 u16 family)
{
	u32 secmark_perm;
	u32 peer_sid;
	struct sock *sk;
	struct common_audit_data ad;
	struct lsm_network_audit net = {0,};
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;

	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_ip_postroute_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
	if (!selinux_policycap_netpeer)
		return selinux_ip_postroute_compat(skb, ifindex, family);

	secmark_active = selinux_secmark_enabled();
	peerlbl_active = selinux_peerlbl_enabled();
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;

	sk = skb->sk;

#ifdef CONFIG_XFRM
	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
	 * packet transformation so allow the packet to pass without any checks
	 * since we'll have another chance to perform access control checks
	 * when the packet is on it's final way out.
	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
	 *       is NULL, in this case go ahead and apply access control.
	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
	 *       TCP listening state we cannot wait until the XFRM processing
	 *       is done as we will miss out on the SA label if we do;
	 *       unfortunately, this means more work, but it is only once per
	 *       connection. */
	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
	    !(sk != NULL && sk->sk_state == TCP_LISTEN))
		return NF_ACCEPT;
#endif

	if (sk == NULL) {
		/* Without an associated socket the packet is either coming
		 * from the kernel or it is being forwarded; check the packet
		 * to determine which and if the packet is being forwarded
		 * query the packet directly to determine the security label. */
		if (skb->skb_iif) {
			secmark_perm = PACKET__FORWARD_OUT;
			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
				return NF_DROP;
		} else {
			secmark_perm = PACKET__SEND;
			peer_sid = SECINITSID_KERNEL;
		}
	} else if (sk->sk_state == TCP_LISTEN) {
		/* Locally generated packet but the associated socket is in the
		 * listening state which means this is a SYN-ACK packet.  In
		 * this particular case the correct security label is assigned
		 * to the connection/request_sock but unfortunately we can't
		 * query the request_sock as it isn't queued on the parent
		 * socket until after the SYN-ACK packet is sent; the only
		 * viable choice is to regenerate the label like we do in
		 * selinux_inet_conn_request().  See also selinux_ip_output()
		 * for similar problems. */
		u32 skb_sid;
		struct sk_security_struct *sksec = sk->sk_security;
		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
			return NF_DROP;
		/* At this point, if the returned skb peerlbl is SECSID_NULL
		 * and the packet has been through at least one XFRM
		 * transformation then we must be dealing with the "final"
		 * form of labeled IPsec packet; since we've already applied
		 * all of our access controls on this packet we can safely
		 * pass the packet. */
		if (skb_sid == SECSID_NULL) {
			switch (family) {
			case PF_INET:
				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
					return NF_ACCEPT;
				break;
			case PF_INET6:
				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
					return NF_ACCEPT;
			default:
				return NF_DROP_ERR(-ECONNREFUSED);
			}
		}
		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
			return NF_DROP;
		secmark_perm = PACKET__SEND;
	} else {
		/* Locally generated packet, fetch the security label from the
		 * associated socket. */
		struct sk_security_struct *sksec = sk->sk_security;
		peer_sid = sksec->sid;
		secmark_perm = PACKET__SEND;
	}

	ad.type = LSM_AUDIT_DATA_NET;
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
		return NF_DROP;

	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, secmark_perm, &ad))
			return NF_DROP_ERR(-ECONNREFUSED);

	if (peerlbl_active) {
		u32 if_sid;
		u32 node_sid;

		if (sel_netif_sid(ifindex, &if_sid))
			return NF_DROP;
		if (avc_has_perm(peer_sid, if_sid,
				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
			return NF_DROP_ERR(-ECONNREFUSED);

		if (sel_netnode_sid(addrp, family, &node_sid))
			return NF_DROP;
		if (avc_has_perm(peer_sid, node_sid,
				 SECCLASS_NODE, NODE__SENDTO, &ad))
			return NF_DROP_ERR(-ECONNREFUSED);
	}

	return NF_ACCEPT;
}

Project: linux
File: hooks.c

static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
{
	u32 size;
	int error;
	char *context = NULL;
	struct inode_security_struct *isec = inode->i_security;

	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;

	/*
	 * If the caller has CAP_MAC_ADMIN, then get the raw context
	 * value even if it is not defined by current policy; otherwise,
	 * use the in-core value under current policy.
	 * Use the non-auditing forms of the permission checks since
	 * getxattr may be called by unprivileged processes commonly
	 * and lack of permission just means that we fall back to the
	 * in-core context value, not a denial.
	 */
	error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
				SECURITY_CAP_NOAUDIT);
	if (!error)
		error = security_sid_to_context_force(isec->sid, &context,
						      &size);
	else
		error = security_sid_to_context(isec->sid, &context, &size);
	if (error)
		return error;
	error = size;
	if (alloc) {
		*buffer = context;
		goto out_nofree;
	}
	kfree(context);
out_nofree:
	return error;
}

Project: linux
File: hooks.c

static void selinux_nf_ip_exit(void)
{
	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");

	nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
#endif	/* IPV6 */
}

Project: linux
File: hooks.c

static int selinux_parse_opts_str(char *options,
				  struct security_mnt_opts *opts)
{
	char *p;
	char *context = NULL, *defcontext = NULL;
	char *fscontext = NULL, *rootcontext = NULL;
	int rc, num_mnt_opts = 0;

	opts->num_mnt_opts = 0;

	/* Standard string-based options. */
	while ((p = strsep(&options, "|")) != NULL) {
		int token;
		substring_t args[MAX_OPT_ARGS];

		if (!*p)
			continue;

		token = match_token(p, tokens, args);

		switch (token) {
		case Opt_context:
			if (context || defcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			context = match_strdup(&args[0]);
			if (!context) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_fscontext:
			if (fscontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			fscontext = match_strdup(&args[0]);
			if (!fscontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_rootcontext:
			if (rootcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			rootcontext = match_strdup(&args[0]);
			if (!rootcontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_defcontext:
			if (context || defcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			defcontext = match_strdup(&args[0]);
			if (!defcontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;
		case Opt_labelsupport:
			break;
		default:
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux:  unknown mount option\n");
			goto out_err;

		}
	}

	rc = -ENOMEM;
	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts)
		goto out_err;

	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
		kfree(opts->mnt_opts);
		goto out_err;
	}

	if (fscontext) {
		opts->mnt_opts[num_mnt_opts] = fscontext;
		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
	}
	if (context) {
		opts->mnt_opts[num_mnt_opts] = context;
		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
	}
	if (rootcontext) {
		opts->mnt_opts[num_mnt_opts] = rootcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
	}
	if (defcontext) {
		opts->mnt_opts[num_mnt_opts] = defcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
	}

	opts->num_mnt_opts = num_mnt_opts;
	return 0;

out_err:
	kfree(context);
	kfree(defcontext);
	kfree(fscontext);
	kfree(rootcontext);
	return rc;
}

Project: linux
File: hooks.c

static int selinux_proc_get_sid(struct dentry *dentry,
				u16 tclass,
				u32 *sid)
{
	return -EINVAL;
}

Project: linux
File: hooks.c

static inline int file_path_has_perm(const struct cred *cred,
				     struct file *file,
				     u32 av)
{
	struct common_audit_data ad;

	ad.type = LSM_AUDIT_DATA_PATH;
	ad.u.path = file->f_path;
	return inode_has_perm(cred, file_inode(file), av, &ad);
}

Project: linux
File: hooks.c

static int selinux_proc_get_sid(struct dentry *dentry,
				u16 tclass,
				u32 *sid)
{
	int rc;
	char *buffer, *path;

	buffer = (char *)__get_free_page(GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
	if (IS_ERR(path))
		rc = PTR_ERR(path);
	else {
		/* each process gets a /proc/PID/ entry. Strip off the
		 * PID part to get a valid selinux labeling.
		 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
		while (path[1] >= '0' && path[1] <= '9') {
			path[1] = '/';
			path++;
		}
		rc = security_genfs_sid("proc", path, tclass, sid);
	}
	free_page((unsigned long)buffer);
	return rc;
}

Project: linux
File: hooks.c

static int selinux_set_mnt_opts(struct super_block *sb,
				struct security_mnt_opts *opts,
				unsigned long kern_flags,
				unsigned long *set_kern_flags)
{
	const struct cred *cred = current_cred();
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	const char *name = sb->s_type->name;
	struct inode *inode = sbsec->sb->s_root->d_inode;
	struct inode_security_struct *root_isec = inode->i_security;
	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
	u32 defcontext_sid = 0;
	char **mount_options = opts->mnt_opts;
	int *flags = opts->mnt_opts_flags;
	int num_opts = opts->num_mnt_opts;

	mutex_lock(&sbsec->lock);

	if (!ss_initialized) {
		if (!num_opts) {
			/* Defer initialization until selinux_complete_init,
			   after the initial policy is loaded and the security
			   server is ready to handle calls. */
			goto out;
		}
		rc = -EINVAL;
		printk(KERN_WARNING "SELinux: Unable to set superblock options "
			"before the security server is initialized\n");
		goto out;
	}
	if (kern_flags && !set_kern_flags) {
		/* Specifying internal flags without providing a place to
		 * place the results is not allowed */
		rc = -EINVAL;
		goto out;
	}

	/*
	 * Binary mount data FS will come through this function twice.  Once
	 * from an explicit call and once from the generic calls from the vfs.
	 * Since the generic VFS calls will not contain any security mount data
	 * we need to skip the double mount verification.
	 *
	 * This does open a hole in which we will not notice if the first
	 * mount using this sb set explict options and a second mount using
	 * this sb does not set any security options.  (The first options
	 * will be used for both mounts)
	 */
	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
	    && (num_opts == 0))
		goto out;

	/*
	 * parse the mount options, check if they are valid sids.
	 * also check if someone is trying to mount the same sb more
	 * than once with different security options.
	 */
	for (i = 0; i < num_opts; i++) {
		u32 sid;

		if (flags[i] == SBLABEL_MNT)
			continue;
		rc = security_context_to_sid(mount_options[i],
					     strlen(mount_options[i]), &sid, GFP_KERNEL);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, name, rc);
			goto out;
		}
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			fscontext_sid = sid;

			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
					fscontext_sid))
				goto out_double_mount;

			sbsec->flags |= FSCONTEXT_MNT;
			break;
		case CONTEXT_MNT:
			context_sid = sid;

			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
					context_sid))
				goto out_double_mount;

			sbsec->flags |= CONTEXT_MNT;
			break;
		case ROOTCONTEXT_MNT:
			rootcontext_sid = sid;

			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
					rootcontext_sid))
				goto out_double_mount;

			sbsec->flags |= ROOTCONTEXT_MNT;

			break;
		case DEFCONTEXT_MNT:
			defcontext_sid = sid;

			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
					defcontext_sid))
				goto out_double_mount;

			sbsec->flags |= DEFCONTEXT_MNT;

			break;
		default:
			rc = -EINVAL;
			goto out;
		}
	}

	if (sbsec->flags & SE_SBINITIALIZED) {
		/* previously mounted with options, but not on this attempt? */
		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
			goto out_double_mount;
		rc = 0;
		goto out;
	}

	if (strcmp(sb->s_type->name, "proc") == 0)
		sbsec->flags |= SE_SBPROC;

	if (!sbsec->behavior) {
		/*
		 * Determine the labeling behavior to use for this
		 * filesystem type.
		 */
		rc = security_fs_use(sb);
		if (rc) {
			printk(KERN_WARNING
				"%s: security_fs_use(%s) returned %d\n",
					__func__, sb->s_type->name, rc);
			goto out;
		}
	}
	/* sets the context of the superblock for the fs being mounted. */
	if (fscontext_sid) {
		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
		if (rc)
			goto out;

		sbsec->sid = fscontext_sid;
	}

	/*
	 * Switch to using mount point labeling behavior.
	 * sets the label used on all file below the mountpoint, and will set
	 * the superblock context if not already set.
	 */
	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
		sbsec->behavior = SECURITY_FS_USE_NATIVE;
		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
	}

	if (context_sid) {
		if (!fscontext_sid) {
			rc = may_context_mount_sb_relabel(context_sid, sbsec,
							  cred);
			if (rc)
				goto out;
			sbsec->sid = context_sid;
		} else {
			rc = may_context_mount_inode_relabel(context_sid, sbsec,
							     cred);
			if (rc)
				goto out;
		}
		if (!rootcontext_sid)
			rootcontext_sid = context_sid;

		sbsec->mntpoint_sid = context_sid;
		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
	}

	if (rootcontext_sid) {
		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
						     cred);
		if (rc)
			goto out;

		root_isec->sid = rootcontext_sid;
		root_isec->initialized = 1;
	}

	if (defcontext_sid) {
		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux: defcontext option is "
			       "invalid for this filesystem type\n");
			goto out;
		}

		if (defcontext_sid != sbsec->def_sid) {
			rc = may_context_mount_inode_relabel(defcontext_sid,
							     sbsec, cred);
			if (rc)
				goto out;
		}

		sbsec->def_sid = defcontext_sid;
	}

	rc = sb_finish_set_opts(sb);
out:
	mutex_unlock(&sbsec->lock);
	return rc;
out_double_mount:
	rc = -EINVAL;
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
	goto out;
}

Project: linux
File: hooks.c

static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
	const struct cred *cred = current_cred();
	unsigned int ia_valid = iattr->ia_valid;
	__u32 av = FILE__WRITE;

	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
	if (ia_valid & ATTR_FORCE) {
		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
			      ATTR_FORCE);
		if (!ia_valid)
			return 0;
	}

	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
		return dentry_has_perm(cred, dentry, FILE__SETATTR);

	if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE))
		av |= FILE__OPEN;

	return dentry_has_perm(cred, dentry, av);
}

Project: linux
File: hooks.c

static inline u16 socket_type_to_security_class(int family, int type, int protocol)
{
	switch (family) {
	case PF_UNIX:
		switch (type) {
		case SOCK_STREAM:
		case SOCK_SEQPACKET:
			return SECCLASS_UNIX_STREAM_SOCKET;
		case SOCK_DGRAM:
			return SECCLASS_UNIX_DGRAM_SOCKET;
		}
		break;
	case PF_INET:
	case PF_INET6:
		switch (type) {
		case SOCK_STREAM:
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
		case SOCK_DGRAM:
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
		default:
			return SECCLASS_RAWIP_SOCKET;
		}
		break;
	case PF_NETLINK:
		switch (protocol) {
		case NETLINK_ROUTE:
			return SECCLASS_NETLINK_ROUTE_SOCKET;
		case NETLINK_FIREWALL:
			return SECCLASS_NETLINK_FIREWALL_SOCKET;
		case NETLINK_SOCK_DIAG:
			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
		case NETLINK_NFLOG:
			return SECCLASS_NETLINK_NFLOG_SOCKET;
		case NETLINK_XFRM:
			return SECCLASS_NETLINK_XFRM_SOCKET;
		case NETLINK_SELINUX:
			return SECCLASS_NETLINK_SELINUX_SOCKET;
		case NETLINK_AUDIT:
			return SECCLASS_NETLINK_AUDIT_SOCKET;
		case NETLINK_IP6_FW:
			return SECCLASS_NETLINK_IP6FW_SOCKET;
		case NETLINK_DNRTMSG:
			return SECCLASS_NETLINK_DNRT_SOCKET;
		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
	}

	return SECCLASS_SOCKET;
}

Project: linux
File: hooks.c

int selinux_disable(void)
{
	if (ss_initialized) {
		/* Not permitted after initial policy load. */
		return -EINVAL;
	}

	if (selinux_disabled) {
		/* Only do this once. */
		return -EINVAL;
	}

	printk(KERN_INFO "SELinux:  Disabled at runtime.\n");

	selinux_disabled = 1;
	selinux_enabled = 0;

	reset_security_ops();

	/* Try to destroy the avc node cache */
	avc_disable();

	/* Unregister netfilter hooks. */
	selinux_nf_ip_exit();

	/* Unregister selinuxfs. */
	exit_sel_fs();

	return 0;
}

Project: linux
File: hooks.c

static void file_free_security(struct file *file)
{
	struct file_security_struct *fsec = file->f_security;
	file->f_security = NULL;
	kfree(fsec);
}

Project: linux
File: hooks.c

static void selinux_task_to_inode(struct task_struct *p,
				  struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
	u32 sid = task_sid(p);

	isec->sid = sid;
	isec->initialized = 1;
}

Project: linux
File: hooks.c

static int selinux_inode_setsecurity(struct inode *inode, const char *name,
				     const void *value, size_t size, int flags)
{
	struct inode_security_struct *isec = inode->i_security;
	u32 newsid;
	int rc;

	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;

	if (!value || !size)
		return -EACCES;

	rc = security_context_to_sid((void *)value, size, &newsid, GFP_KERNEL);
	if (rc)
		return rc;

	isec->sclass = inode_mode_to_security_class(inode->i_mode);
	isec->sid = newsid;
	isec->initialized = 1;
	return 0;
}

Project: linux
File: hooks.c

static int selinux_bprm_set_creds(struct linux_binprm *bprm)
{
	const struct task_security_struct *old_tsec;
	struct task_security_struct *new_tsec;
	struct inode_security_struct *isec;
	struct common_audit_data ad;
	struct inode *inode = file_inode(bprm->file);
	int rc;

	rc = cap_bprm_set_creds(bprm);
	if (rc)
		return rc;

	/* SELinux context only depends on initial program or script and not
	 * the script interpreter */
	if (bprm->cred_prepared)
		return 0;

	old_tsec = current_security();
	new_tsec = bprm->cred->security;
	isec = inode->i_security;

	/* Default to the current task SID. */
	new_tsec->sid = old_tsec->sid;
	new_tsec->osid = old_tsec->sid;

	/* Reset fs, key, and sock SIDs on execve. */
	new_tsec->create_sid = 0;
	new_tsec->keycreate_sid = 0;
	new_tsec->sockcreate_sid = 0;

	if (old_tsec->exec_sid) {
		new_tsec->sid = old_tsec->exec_sid;
		/* Reset exec SID on execve. */
		new_tsec->exec_sid = 0;

		/* Fail on NNP or nosuid if not an allowed transition. */
		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
		if (rc)
			return rc;
	} else {
		/* Check for a default transition on this program. */
		rc = security_transition_sid(old_tsec->sid, isec->sid,
					     SECCLASS_PROCESS, NULL,
					     &new_tsec->sid);
		if (rc)
			return rc;

		/*
		 * Fallback to old SID on NNP or nosuid if not an allowed
		 * transition.
		 */
		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
		if (rc)
			new_tsec->sid = old_tsec->sid;
	}

	ad.type = LSM_AUDIT_DATA_PATH;
	ad.u.path = bprm->file->f_path;

	if (new_tsec->sid == old_tsec->sid) {
		rc = avc_has_perm(old_tsec->sid, isec->sid,
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		/* Check permissions for the transition. */
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

		rc = avc_has_perm(new_tsec->sid, isec->sid,
				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
		if (rc)
			return rc;

		/* Check for shared state */
		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
					  SECCLASS_PROCESS, PROCESS__SHARE,
					  NULL);
			if (rc)
				return -EPERM;
		}

		/* Make sure that anyone attempting to ptrace over a task that
		 * changes its SID has the appropriate permit */
		if (bprm->unsafe &
		    (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
			struct task_struct *tracer;
			struct task_security_struct *sec;
			u32 ptsid = 0;

			rcu_read_lock();
			tracer = ptrace_parent(current);
			if (likely(tracer != NULL)) {
				sec = __task_cred(tracer)->security;
				ptsid = sec->sid;
			}
			rcu_read_unlock();

			if (ptsid != 0) {
				rc = avc_has_perm(ptsid, new_tsec->sid,
						  SECCLASS_PROCESS,
						  PROCESS__PTRACE, NULL);
				if (rc)
					return -EPERM;
			}
		}

		/* Clear any possibly unsafe personality bits on exec: */
		bprm->per_clear |= PER_CLEAR_ON_SETID;
	}

	return 0;
}

Project: linux
File: hooks.c

static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops,
					 struct sk_buff *skb,
					 const struct net_device *in,
					 const struct net_device *out,
					 int (*okfn)(struct sk_buff *))
{
	return selinux_ip_forward(skb, in->ifindex, PF_INET);
}

Project: linux
File: hooks.c

static int selinux_ptrace_access_check(struct task_struct *child,
				     unsigned int mode)
{
	int rc;

	rc = cap_ptrace_access_check(child, mode);
	if (rc)
		return rc;

	if (mode & PTRACE_MODE_READ) {
		u32 sid = current_sid();
		u32 csid = task_sid(child);
		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
	}

	return current_has_perm(child, PROCESS__PTRACE);
}

Project: linux
File: hooks.c

static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	int err;
	struct sk_security_struct *sksec = sk->sk_security;
	u16 family = sk->sk_family;
	u32 sk_sid = sksec->sid;
	struct common_audit_data ad;
	struct lsm_network_audit net = {0,};
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;

	if (family != PF_INET && family != PF_INET6)
		return 0;

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;

	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_sock_rcv_skb_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
	if (!selinux_policycap_netpeer)
		return selinux_sock_rcv_skb_compat(sk, skb, family);

	secmark_active = selinux_secmark_enabled();
	peerlbl_active = selinux_peerlbl_enabled();
	if (!secmark_active && !peerlbl_active)
		return 0;

	ad.type = LSM_AUDIT_DATA_NET;
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
	if (err)
		return err;

	if (peerlbl_active) {
		u32 peer_sid;

		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
		if (err)
			return err;
		err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
					       peer_sid, &ad);
		if (err) {
			selinux_netlbl_err(skb, err, 0);
			return err;
		}
		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
				   PEER__RECV, &ad);
		if (err) {
			selinux_netlbl_err(skb, err, 0);
			return err;
		}
	}

	if (secmark_active) {
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
				   PACKET__RECV, &ad);
		if (err)
			return err;
	}

	return err;
}

Project: linux
File: hooks.c

static int cred_has_capability(const struct cred *cred,
			       int cap, int audit)
{
	struct common_audit_data ad;
	struct av_decision avd;
	u16 sclass;
	u32 sid = cred_sid(cred);
	u32 av = CAP_TO_MASK(cap);
	int rc;

	ad.type = LSM_AUDIT_DATA_CAP;
	ad.u.cap = cap;

	switch (CAP_TO_INDEX(cap)) {
	case 0:
		sclass = SECCLASS_CAPABILITY;
		break;
	case 1:
		sclass = SECCLASS_CAPABILITY2;
		break;
	default:
		printk(KERN_ERR
		       "SELinux:  out of range capability %d\n", cap);
		BUG();
		return -EINVAL;
	}

	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
	if (audit == SECURITY_CAP_AUDIT) {
		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
		if (rc2)
			return rc2;
	}
	return rc;
}

Project: linux
File: hooks.c

static int selinux_mmap_addr(unsigned long addr)
{
	int rc;

	/* do DAC check on address space usage */
	rc = cap_mmap_addr(addr);
	if (rc)
		return rc;

	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
		u32 sid = current_sid();
		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
				  MEMPROTECT__MMAP_ZERO, NULL);
	}

	return rc;
}

Project: linux
File: hooks.c

static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

	ret = avc_has_perm(sid, isec->sid,
			   SECCLASS_KERNEL_SERVICE,
			   KERNEL_SERVICE__CREATE_FILES_AS,
			   NULL);

	if (ret == 0)
		tsec->create_sid = isec->sid;
	return ret;
}

Project: linux
File: hooks.c

static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
				  const void *value, size_t size, int flags)
{
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec;
	struct common_audit_data ad;
	u32 newsid, sid = current_sid();
	int rc = 0;

	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);

	sbsec = inode->i_sb->s_security;
	if (!(sbsec->flags & SBLABEL_MNT))
		return -EOPNOTSUPP;

	if (!inode_owner_or_capable(inode))
		return -EPERM;

	ad.type = LSM_AUDIT_DATA_DENTRY;
	ad.u.dentry = dentry;

	rc = avc_has_perm(sid, isec->sid, isec->sclass,
			  FILE__RELABELFROM, &ad);
	if (rc)
		return rc;

	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
	if (rc == -EINVAL) {
		if (!capable(CAP_MAC_ADMIN)) {
			struct audit_buffer *ab;
			size_t audit_size;
			const char *str;

			/* We strip a nul only if it is at the end, otherwise the
			 * context contains a nul and we should audit that */
			if (value) {
				str = value;
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
			} else {
				str = "";
				audit_size = 0;
			}
			ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
			audit_log_format(ab, "op=setxattr invalid_context=");
			audit_log_n_untrustedstring(ab, value, audit_size);
			audit_log_end(ab);

			return rc;
		}
		rc = security_context_to_sid_force(value, size, &newsid);
	}
	if (rc)
		return rc;

	rc = avc_has_perm(sid, newsid, isec->sclass,
			  FILE__RELABELTO, &ad);
	if (rc)
		return rc;

	rc = security_validate_transition(isec->sid, newsid, sid,
					  isec->sclass);
	if (rc)
		return rc;

	return avc_has_perm(newsid,
			    sbsec->sid,
			    SECCLASS_FILESYSTEM,
			    FILESYSTEM__ASSOCIATE,
			    &ad);
}

Project: linux
File: hooks.c

static int selinux_task_setscheduler(struct task_struct *p)
{
	int rc;

	rc = cap_task_setscheduler(p);
	if (rc)
		return rc;

	return current_has_perm(p, PROCESS__SETSCHED);
}

Project: linux
File: hooks.c

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;

	sksec->peer_sid = SECINITSID_UNLABELED;
	sksec->sid = SECINITSID_UNLABELED;
	selinux_netlbl_sk_security_reset(sksec);
	sk->sk_security = sksec;

	return 0;
}

Project: linux
File: hooks.c

static void selinux_sock_graft(struct sock *sk, struct socket *parent)
{
	struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
	struct sk_security_struct *sksec = sk->sk_security;

	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
	    sk->sk_family == PF_UNIX)
		isec->sid = sksec->sid;
	sksec->sclass = isec->sclass;
}

Project: linux
File: hooks.c

static void selinux_write_opts(struct seq_file *m,
			       struct security_mnt_opts *opts)
{
	int i;
	char *prefix;

	for (i = 0; i < opts->num_mnt_opts; i++) {
		char *has_comma;

		if (opts->mnt_opts[i])
			has_comma = strchr(opts->mnt_opts[i], ',');
		else
			has_comma = NULL;

		switch (opts->mnt_opts_flags[i]) {
		case CONTEXT_MNT:
			prefix = CONTEXT_STR;
			break;
		case FSCONTEXT_MNT:
			prefix = FSCONTEXT_STR;
			break;
		case ROOTCONTEXT_MNT:
			prefix = ROOTCONTEXT_STR;
			break;
		case DEFCONTEXT_MNT:
			prefix = DEFCONTEXT_STR;
			break;
		case SBLABEL_MNT:
			seq_putc(m, ',');
			seq_puts(m, LABELSUPP_STR);
			continue;
		default:
			BUG();
			return;
		};
		/* we need a comma before each option */
		seq_putc(m, ',');
		seq_puts(m, prefix);
		if (has_comma)
			seq_putc(m, '\"');
		seq_puts(m, opts->mnt_opts[i]);
		if (has_comma)
			seq_putc(m, '\"');
	}
}

Project: linux
File: hooks.c

static int check_nnp_nosuid(const struct linux_binprm *bprm,
			    const struct task_security_struct *old_tsec,
			    const struct task_security_struct *new_tsec)
{
	int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
	int nosuid = (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID);
	int rc;

	if (!nnp && !nosuid)
		return 0; /* neither NNP nor nosuid */

	if (new_tsec->sid == old_tsec->sid)
		return 0; /* No change in credentials */

	/*
	 * The only transitions we permit under NNP or nosuid
	 * are transitions to bounded SIDs, i.e. SIDs that are
	 * guaranteed to only be allowed a subset of the permissions
	 * of the current SID.
	 */
	rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
	if (rc) {
		/*
		 * On failure, preserve the errno values for NNP vs nosuid.
		 * NNP:  Operation not permitted for caller.
		 * nosuid:  Permission denied to file.
		 */
		if (nnp)
			return -EPERM;
		else
			return -EACCES;
	}
	return 0;
}

Project: linux
File: hooks.c

static int selinux_mount(const char *dev_name,
			 struct path *path,
			 const char *type,
			 unsigned long flags,
			 void *data)
{
	const struct cred *cred = current_cred();

	if (flags & MS_REMOUNT)
		return superblock_has_perm(cred, path->dentry->d_sb,
					   FILESYSTEM__REMOUNT, NULL);
	else
		return path_has_perm(cred, path, FILE__MOUNTON);
}

Project: linux
File: hooks.c

static int selinux_file_ioctl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
	const struct cred *cred = current_cred();
	int error = 0;

	switch (cmd) {
	case FIONREAD:
	/* fall through */
	case FIBMAP:
	/* fall through */
	case FIGETBSZ:
	/* fall through */
	case FS_IOC_GETFLAGS:
	/* fall through */
	case FS_IOC_GETVERSION:
		error = file_has_perm(cred, file, FILE__GETATTR);
		break;

	case FS_IOC_SETFLAGS:
	/* fall through */
	case FS_IOC_SETVERSION:
		error = file_has_perm(cred, file, FILE__SETATTR);
		break;

	/* sys_ioctl() checks */
	case FIONBIO:
	/* fall through */
	case FIOASYNC:
		error = file_has_perm(cred, file, 0);
		break;

	case KDSKBENT:
	case KDSKBSENT:
		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
					    SECURITY_CAP_AUDIT);
		break;

	/* default case assumes that the command will go
	 * to the file's ioctl() function.
	 */
	default:
		error = file_has_perm(cred, file, FILE__IOCTL);
	}
	return error;
}

Project: linux
File: hooks.c

static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
{
	int err = 0;
	u32 perm;
	struct nlmsghdr *nlh;
	struct sk_security_struct *sksec = sk->sk_security;

	if (skb->len < NLMSG_HDRLEN) {
		err = -EINVAL;
		goto out;
	}
	nlh = nlmsg_hdr(skb);

	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
	if (err) {
		if (err == -EINVAL) {
			audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
				  "SELinux:  unrecognized netlink message"
				  " type=%hu for sclass=%hu\n",
				  nlh->nlmsg_type, sksec->sclass);
			if (!selinux_enforcing || security_get_allow_unknown())
				err = 0;
		}

		/* Ignore */
		if (err == -ENOENT)
			err = 0;
		goto out;
	}

	err = sock_has_perm(current, sk, perm);
out:
	return err;
}

Project: linux
File: hooks.c

static int may_link(struct inode *dir,
		    struct dentry *dentry,
		    int kind)

{
	struct inode_security_struct *dsec, *isec;
	struct common_audit_data ad;
	u32 sid = current_sid();
	u32 av;
	int rc;

	dsec = dir->i_security;
	isec = dentry->d_inode->i_security;

	ad.type = LSM_AUDIT_DATA_DENTRY;
	ad.u.dentry = dentry;

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
	if (rc)
		return rc;

	switch (kind) {
	case MAY_LINK:
		av = FILE__LINK;
		break;
	case MAY_UNLINK:
		av = FILE__UNLINK;
		break;
	case MAY_RMDIR:
		av = DIR__RMDIR;
		break;
	default:
		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
			__func__, kind);
		return 0;
	}

	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
	return rc;
}

Project: linux
File: hooks.c

static unsigned int selinux_ip_output(struct sk_buff *skb,
				      u16 family)
{
	struct sock *sk;
	u32 sid;

	if (!netlbl_enabled())
		return NF_ACCEPT;

	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
	 * because we want to make sure we apply the necessary labeling
	 * before IPsec is applied so we can leverage AH protection */
	sk = skb->sk;
	if (sk) {
		struct sk_security_struct *sksec;

		if (sk->sk_state == TCP_LISTEN)
			/* if the socket is the listening state then this
			 * packet is a SYN-ACK packet which means it needs to
			 * be labeled based on the connection/request_sock and
			 * not the parent socket.  unfortunately, we can't
			 * lookup the request_sock yet as it isn't queued on
			 * the parent socket until after the SYN-ACK is sent.
			 * the "solution" is to simply pass the packet as-is
			 * as any IP option based labeling should be copied
			 * from the initial connection request (in the IP
			 * layer).  it is far from ideal, but until we get a
			 * security label in the packet itself this is the
			 * best we can do. */
			return NF_ACCEPT;

		/* standard practice, label using the parent socket */
		sksec = sk->sk_security;
		sid = sksec->sid;
	} else
		sid = SECINITSID_KERNEL;
	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
		return NF_DROP;

	return NF_ACCEPT;
}

Project: linux
File: hooks.c

static int inode_alloc_security(struct inode *inode)
{
	struct inode_security_struct *isec;
	u32 sid = current_sid();

	isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
	if (!isec)
		return -ENOMEM;

	mutex_init(&isec->lock);
	INIT_LIST_HEAD(&isec->list);
	isec->inode = inode;
	isec->sid = SECINITSID_UNLABELED;
	isec->sclass = SECCLASS_FILE;
	isec->task_sid = sid;
	inode->i_security = isec;

	return 0;
}

Project: linux
File: hooks.c

static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
{
	u32 peer_secid = SECSID_NULL;
	u16 family;

	if (skb && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;
	else if (skb && skb->protocol == htons(ETH_P_IPV6))
		family = PF_INET6;
	else if (sock)
		family = sock->sk->sk_family;
	else
		goto out;

	if (sock && family == PF_UNIX)
		selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
	else if (skb)
		selinux_skb_peerlbl_sid(skb, family, &peer_secid);

out:
	*secid = peer_secid;
	if (peer_secid == SECSID_NULL)
		return -EINVAL;
	return 0;
}

Project: linux
File: hooks.c

static inline int path_has_perm(const struct cred *cred,
				struct path *path,
				u32 av)
{
	struct inode *inode = path->dentry->d_inode;
	struct common_audit_data ad;

	ad.type = LSM_AUDIT_DATA_PATH;
	ad.u.path = *path;
	return inode_has_perm(cred, inode, av, &ad);
}

Project: linux
File: hooks.c

static int sb_finish_set_opts(struct super_block *sb)
{
	struct superblock_security_struct *sbsec = sb->s_security;
	struct dentry *root = sb->s_root;
	struct inode *root_inode = root->d_inode;
	int rc = 0;

	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
		/* Make sure that the xattr handler exists and that no
		   error other than -ENODATA is returned by getxattr on
		   the root directory.  -ENODATA is ok, as this may be
		   the first boot of the SELinux kernel before we have
		   assigned xattr values to the filesystem. */
		if (!root_inode->i_op->getxattr) {
			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
			       "xattr support\n", sb->s_id, sb->s_type->name);
			rc = -EOPNOTSUPP;
			goto out;
		}
		rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
		if (rc < 0 && rc != -ENODATA) {
			if (rc == -EOPNOTSUPP)
				printk(KERN_WARNING "SELinux: (dev %s, type "
				       "%s) has no security xattr handler\n",
				       sb->s_id, sb->s_type->name);
			else
				printk(KERN_WARNING "SELinux: (dev %s, type "
				       "%s) getxattr errno %d\n", sb->s_id,
				       sb->s_type->name, -rc);
			goto out;
		}
	}

	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
		       sb->s_id, sb->s_type->name);
	else
		printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
		       sb->s_id, sb->s_type->name,
		       labeling_behaviors[sbsec->behavior-1]);

	sbsec->flags |= SE_SBINITIALIZED;
	if (selinux_is_sblabel_mnt(sb))
		sbsec->flags |= SBLABEL_MNT;

	/* Initialize the root inode. */
	rc = inode_doinit_with_dentry(root_inode, root);

	/* Initialize any other inodes associated with the superblock, e.g.
	   inodes created prior to initial policy load or inodes created
	   during get_sb by a pseudo filesystem that directly
	   populates itself. */
	spin_lock(&sbsec->isec_lock);
next_inode:
	if (!list_empty(&sbsec->isec_head)) {
		struct inode_security_struct *isec =
				list_entry(sbsec->isec_head.next,
					   struct inode_security_struct, list);
		struct inode *inode = isec->inode;
		spin_unlock(&sbsec->isec_lock);
		inode = igrab(inode);
		if (inode) {
			if (!IS_PRIVATE(inode))
				inode_doinit(inode);
			iput(inode);
		}
		spin_lock(&sbsec->isec_lock);
		list_del_init(&isec->list);
		goto next_inode;
	}
	spin_unlock(&sbsec->isec_lock);
out:
	return rc;
}

Project: linux
File: hooks.c

static int selinux_file_permission(struct file *file, int mask)
{
	struct inode *inode = file_inode(file);
	struct file_security_struct *fsec = file->f_security;
	struct inode_security_struct *isec = inode->i_security;
	u32 sid = current_sid();

	if (!mask)
		/* No permission to check.  Existence test. */
		return 0;

	if (sid == fsec->sid && fsec->isid == isec->sid &&
	    fsec->pseqno == avc_policy_seqno())
		/* No change since file_open check. */
		return 0;

	return selinux_revalidate_file_permission(file, mask);
}

Project: linux
File: hooks.c

static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
	const struct cred *cred = current_cred();
	struct path path;

	path.dentry = dentry;
	path.mnt = mnt;

	return path_has_perm(cred, &path, FILE__GETATTR);
}

Project: linux
File: hooks.c

static int selinux_socket_post_create(struct socket *sock, int family,
				      int type, int protocol, int kern)
{
	const struct task_security_struct *tsec = current_security();
	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
	struct sk_security_struct *sksec;
	int err = 0;

	isec->sclass = socket_type_to_security_class(family, type, protocol);

	if (kern)
		isec->sid = SECINITSID_KERNEL;
	else {
		err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
		if (err)
			return err;
	}

	isec->initialized = 1;

	if (sock->sk) {
		sksec = sock->sk->sk_security;
		sksec->sid = isec->sid;
		sksec->sclass = isec->sclass;
		err = selinux_netlbl_socket_post_create(sock->sk, family);
	}

	return err;
}

Project: linux
File: hooks.c

static int selinux_setprocattr(struct task_struct *p,
			       char *name, void *value, size_t size)
{
	struct task_security_struct *tsec;
	struct task_struct *tracer;
	struct cred *new;
	u32 sid = 0, ptsid;
	int error;
	char *str = value;

	if (current != p) {
		/* SELinux only allows a process to change its own
		   security attributes. */
		return -EACCES;
	}

	/*
	 * Basic control over ability to set these attributes at all.
	 * current == p, but we'll pass them separately in case the
	 * above restriction is ever removed.
	 */
	if (!strcmp(name, "exec"))
		error = current_has_perm(p, PROCESS__SETEXEC);
	else if (!strcmp(name, "fscreate"))
		error = current_has_perm(p, PROCESS__SETFSCREATE);
	else if (!strcmp(name, "keycreate"))
		error = current_has_perm(p, PROCESS__SETKEYCREATE);
	else if (!strcmp(name, "sockcreate"))
		error = current_has_perm(p, PROCESS__SETSOCKCREATE);
	else if (!strcmp(name, "current"))
		error = current_has_perm(p, PROCESS__SETCURRENT);
	else
		error = -EINVAL;
	if (error)
		return error;

	/* Obtain a SID for the context, if one was specified. */
	if (size && str[1] && str[1] != '\n') {
		if (str[size-1] == '\n') {
			str[size-1] = 0;
			size--;
		}
		error = security_context_to_sid(value, size, &sid, GFP_KERNEL);
		if (error == -EINVAL && !strcmp(name, "fscreate")) {
			if (!capable(CAP_MAC_ADMIN)) {
				struct audit_buffer *ab;
				size_t audit_size;

				/* We strip a nul only if it is at the end, otherwise the
				 * context contains a nul and we should audit that */
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
				ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
				audit_log_format(ab, "op=fscreate invalid_context=");
				audit_log_n_untrustedstring(ab, value, audit_size);
				audit_log_end(ab);

				return error;
			}
			error = security_context_to_sid_force(value, size,
							      &sid);
		}
		if (error)
			return error;
	}

	new = prepare_creds();
	if (!new)
		return -ENOMEM;

	/* Permission checking based on the specified context is
	   performed during the actual operation (execve,
	   open/mkdir/...), when we know the full context of the
	   operation.  See selinux_bprm_set_creds for the execve
	   checks and may_create for the file creation checks. The
	   operation will then fail if the context is not permitted. */
	tsec = new->security;
	if (!strcmp(name, "exec")) {
		tsec->exec_sid = sid;
	} else if (!strcmp(name, "fscreate")) {
		tsec->create_sid = sid;
	} else if (!strcmp(name, "keycreate")) {
		error = may_create_key(sid, p);
		if (error)
			goto abort_change;
		tsec->keycreate_sid = sid;
	} else if (!strcmp(name, "sockcreate")) {
		tsec->sockcreate_sid = sid;
	} else if (!strcmp(name, "current")) {
		error = -EINVAL;
		if (sid == 0)
			goto abort_change;

		/* Only allow single threaded processes to change context */
		error = -EPERM;
		if (!current_is_single_threaded()) {
			error = security_bounded_transition(tsec->sid, sid);
			if (error)
				goto abort_change;
		}

		/* Check permissions for the transition. */
		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
				     PROCESS__DYNTRANSITION, NULL);
		if (error)
			goto abort_change;

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and fail. */
		ptsid = 0;
		rcu_read_lock();
		tracer = ptrace_parent(p);
		if (tracer)
			ptsid = task_sid(tracer);
		rcu_read_unlock();

		if (tracer) {
			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
					     PROCESS__PTRACE, NULL);
			if (error)
				goto abort_change;
		}

		tsec->sid = sid;
	} else {
		error = -EINVAL;
		goto abort_change;
	}

	commit_creds(new);
	return size;

abort_change:
	abort_creds(new);
	return error;
}