Merge branch 'next' into for-linus

Documentation/DocBook/kernel-api.tmpl

@@ -283,6 +283,7 @@ X!Earch/x86/kernel/mca_32.c
   <chapter id="security">
      <title>Security Framework</title>
 !Isecurity/security.c
+!Esecurity/inode.c
   </chapter>
 
   <chapter id="audit">

Documentation/SELinux.txt

+If you want to use SELinux, chances are you will want
+to use the distro-provided policies, or install the
+latest reference policy release from
+	http://oss.tresys.com/projects/refpolicy
+
+However, if you want to install a dummy policy for
+testing, you can do using 'mdp' provided under
+scripts/selinux.  Note that this requires the selinux
+userspace to be installed - in particular you will
+need checkpolicy to compile a kernel, and setfiles and
+fixfiles to label the filesystem.
+
+	1. Compile the kernel with selinux enabled.
+	2. Type 'make' to compile mdp.
+	3. Make sure that you are not running with
+	   SELinux enabled and a real policy.  If
+	   you are, reboot with selinux disabled
+	   before continuing.
+	4. Run install_policy.sh:
+		cd scripts/selinux
+		sh install_policy.sh
+
+Step 4 will create a new dummy policy valid for your
+kernel, with a single selinux user, role, and type.
+It will compile the policy, will set your SELINUXTYPE to
+dummy in /etc/selinux/config, install the compiled policy
+as 'dummy', and relabel your filesystem.

MAINTAINERS

@@ -3650,7 +3650,8 @@ P:	Eric Paris
 M:	eparis@parisplace.org
 L:	linux-kernel@vger.kernel.org (kernel issues)
 L: 	selinux@tycho.nsa.gov (subscribers-only, general discussion)
-W:	http://www.nsa.gov/selinux
+W:	http://selinuxproject.org
+T:	git kernel.org:pub/scm/linux/kernel/git/jmorris/security-testing-2.6.git
 S:	Supported
 
 SENSABLE PHANTOM

drivers/char/tpm/Kconfig

@@ -6,6 +6,7 @@ menuconfig TCG_TPM
 	tristate "TPM Hardware Support"
 	depends on HAS_IOMEM
 	depends on EXPERIMENTAL
+	select SECURITYFS
 	---help---
 	  If you have a TPM security chip in your system, which
 	  implements the Trusted Computing Group's specification,

include/linux/security.h

@@ -1560,11 +1560,6 @@ struct security_operations {
 extern int security_init(void);
 extern int security_module_enable(struct security_operations *ops);
 extern int register_security(struct security_operations *ops);
-extern struct dentry *securityfs_create_file(const char *name, mode_t mode,
-					     struct dentry *parent, void *data,
-					     const struct file_operations *fops);
-extern struct dentry *securityfs_create_dir(const char *name, struct dentry *parent);
-extern void securityfs_remove(struct dentry *dentry);
 
 /* Security operations */
 int security_ptrace_may_access(struct task_struct *child, unsigned int mode);
@@ -2424,25 +2419,6 @@ static inline int security_netlink_recv(struct sk_buff *skb, int cap)
 	return cap_netlink_recv(skb, cap);
 }
 
-static inline struct dentry *securityfs_create_dir(const char *name,
-					struct dentry *parent)
-{
-	return ERR_PTR(-ENODEV);
-}
-
-static inline struct dentry *securityfs_create_file(const char *name,
-						mode_t mode,
-						struct dentry *parent,
-						void *data,
-						const struct file_operations *fops)
-{
-	return ERR_PTR(-ENODEV);
-}
-
-static inline void securityfs_remove(struct dentry *dentry)
-{
-}
-
 static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
 {
 	return -EOPNOTSUPP;
@@ -2806,5 +2782,35 @@ static inline void security_audit_rule_free(void *lsmrule)
 #endif /* CONFIG_SECURITY */
 #endif /* CONFIG_AUDIT */
 
+#ifdef CONFIG_SECURITYFS
+
+extern struct dentry *securityfs_create_file(const char *name, mode_t mode,
+					     struct dentry *parent, void *data,
+					     const struct file_operations *fops);
+extern struct dentry *securityfs_create_dir(const char *name, struct dentry *parent);
+extern void securityfs_remove(struct dentry *dentry);
+
+#else /* CONFIG_SECURITYFS */
+
+static inline struct dentry *securityfs_create_dir(const char *name,
+						   struct dentry *parent)
+{
+	return ERR_PTR(-ENODEV);
+}
+
+static inline struct dentry *securityfs_create_file(const char *name,
+						    mode_t mode,
+						    struct dentry *parent,
+						    void *data,
+						    const struct file_operations *fops)
+{
+	return ERR_PTR(-ENODEV);
+}
+
+static inline void securityfs_remove(struct dentry *dentry)
+{}
+
+#endif
+
 #endif /* ! __LINUX_SECURITY_H */
 

scripts/Makefile

@@ -20,6 +20,7 @@ hostprogs-y += unifdef
 
 subdir-$(CONFIG_MODVERSIONS) += genksyms
 subdir-y                     += mod
+subdir-$(CONFIG_SECURITY_SELINUX) += selinux
 
 # Let clean descend into subdirs
-subdir-	+= basic kconfig package
+subdir-	+= basic kconfig package selinux

scripts/selinux/Makefile

+subdir-y := mdp
+subdir-	+= mdp

scripts/selinux/README

+Please see Documentation/SELinux.txt for information on
+installing a dummy SELinux policy.

scripts/selinux/install_policy.sh

+#!/bin/sh
+if [ `id -u` -ne 0 ]; then
+	echo "$0: must be root to install the selinux policy"
+	exit 1
+fi
+SF=`which setfiles`
+if [ $? -eq 1 ]; then
+	if [ -f /sbin/setfiles ]; then
+		SF="/usr/setfiles"
+	else
+		echo "no selinux tools installed: setfiles"
+		exit 1
+	fi
+fi
+
+cd mdp
+
+CP=`which checkpolicy`
+VERS=`$CP -V | awk '{print $1}'`
+
+./mdp policy.conf file_contexts
+$CP -o policy.$VERS policy.conf
+
+mkdir -p /etc/selinux/dummy/policy
+mkdir -p /etc/selinux/dummy/contexts/files
+
+cp file_contexts /etc/selinux/dummy/contexts/files
+cp dbus_contexts /etc/selinux/dummy/contexts
+cp policy.$VERS /etc/selinux/dummy/policy
+FC_FILE=/etc/selinux/dummy/contexts/files/file_contexts
+
+if [ ! -d /etc/selinux ]; then
+	mkdir -p /etc/selinux
+fi
+if [ ! -f /etc/selinux/config ]; then
+	cat > /etc/selinux/config << EOF
+SELINUX=enforcing
+SELINUXTYPE=dummy
+EOF
+else
+	TYPE=`cat /etc/selinux/config | grep "^SELINUXTYPE" | tail -1 | awk -F= '{ print $2 '}`
+	if [ "eq$TYPE" != "eqdummy" ]; then
+		selinuxenabled
+		if [ $? -eq 0 ]; then
+			echo "SELinux already enabled with a non-dummy policy."
+			echo "Exiting.  Please install policy by hand if that"
+			echo "is what you REALLY want."
+			exit 1
+		fi
+		mv /etc/selinux/config /etc/selinux/config.mdpbak
+		grep -v "^SELINUXTYPE" /etc/selinux/config.mdpbak >> /etc/selinux/config
+		echo "SELINUXTYPE=dummy" >> /etc/selinux/config
+	fi
+fi
+
+cd /etc/selinux/dummy/contexts/files
+$SF file_contexts /
+
+mounts=`cat /proc/$$/mounts | egrep "ext2|ext3|xfs|jfs|ext4|ext4dev|gfs2" | awk '{ print $2 '}`
+$SF file_contexts $mounts
+
+
+dodev=`cat /proc/$$/mounts | grep "/dev "`
+if [ "eq$dodev" != "eq" ]; then
+	mount --move /dev /mnt
+	$SF file_contexts /dev
+	mount --move /mnt /dev
+fi
+

scripts/selinux/mdp/.gitignore

+# Generated file
+mdp

scripts/selinux/mdp/Makefile

+hostprogs-y	:= mdp
+HOST_EXTRACFLAGS += -Isecurity/selinux/include
+
+always		:= $(hostprogs-y)
+clean-files	:= $(hostprogs-y) policy.* file_contexts

scripts/selinux/mdp/dbus_contexts

+<!DOCTYPE busconfig PUBLIC "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
+ "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
+<busconfig>
+  <selinux>
+  </selinux>
+</busconfig>

scripts/selinux/mdp/mdp.c

+/*
+ *
+ * mdp - make dummy policy
+ *
+ * When pointed at a kernel tree, builds a dummy policy for that kernel
+ * with exactly one type with full rights to itself.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2006
+ *
+ * Authors: Serge E. Hallyn <serue@us.ibm.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "flask.h"
+
+void usage(char *name)
+{
+	printf("usage: %s [-m] policy_file context_file\n", name);
+	exit(1);
+}
+
+void find_common_name(char *cname, char *dest, int len)
+{
+	char *start, *end;
+
+	start = strchr(cname, '_')+1;
+	end = strchr(start, '_');
+	if (!start || !end || start-cname > len || end-start > len) {
+		printf("Error with commons defines\n");
+		exit(1);
+	}
+	strncpy(dest, start, end-start);
+	dest[end-start] = '\0';
+}
+
+#define S_(x) x,
+static char *classlist[] = {
+#include "class_to_string.h"
+	NULL
+};
+#undef S_
+
+#include "initial_sid_to_string.h"
+
+#define TB_(x) char *x[] = {
+#define TE_(x) NULL };
+#define S_(x) x,
+#include "common_perm_to_string.h"
+#undef TB_
+#undef TE_
+#undef S_
+
+struct common {
+	char *cname;
+	char **perms;
+};
+struct common common[] = {
+#define TB_(x) { #x, x },
+#define S_(x)
+#define TE_(x)
+#include "common_perm_to_string.h"
+#undef TB_
+#undef TE_
+#undef S_
+};
+
+#define S_(x, y, z) {x, #y},
+struct av_inherit {
+	int class;
+	char *common;
+};
+struct av_inherit av_inherit[] = {
+#include "av_inherit.h"
+};
+#undef S_
+
+#include "av_permissions.h"
+#define S_(x, y, z) {x, y, z},
+struct av_perms {
+	int class;
+	int perm_i;
+	char *perm_s;
+};
+struct av_perms av_perms[] = {
+#include "av_perm_to_string.h"
+};
+#undef S_
+
+int main(int argc, char *argv[])
+{
+	int i, j, mls = 0;
+	char **arg, *polout, *ctxout;
+	int classlist_len, initial_sid_to_string_len;
+	FILE *fout;
+
+	if (argc < 3)
+		usage(argv[0]);
+	arg = argv+1;
+	if (argc==4 && strcmp(argv[1], "-m") == 0) {
+		mls = 1;
+		arg++;
+	}
+	polout = *arg++;
+	ctxout = *arg;
+
+	fout = fopen(polout, "w");
+	if (!fout) {
+		printf("Could not open %s for writing\n", polout);
+		usage(argv[0]);
+	}
+
+	classlist_len = sizeof(classlist) / sizeof(char *);
+	/* print out the classes */
+	for (i=1; i < classlist_len; i++) {
+		if(classlist[i])
+			fprintf(fout, "class %s\n", classlist[i]);
+		else
+			fprintf(fout, "class user%d\n", i);
+	}
+	fprintf(fout, "\n");
+
+	initial_sid_to_string_len = sizeof(initial_sid_to_string) / sizeof (char *);
+	/* print out the sids */
+	for (i=1; i < initial_sid_to_string_len; i++)
+		fprintf(fout, "sid %s\n", initial_sid_to_string[i]);
+	fprintf(fout, "\n");
+
+	/* print out the commons */
+	for (i=0; i< sizeof(common)/sizeof(struct common); i++) {
+		char cname[101];
+		find_common_name(common[i].cname, cname, 100);
+		cname[100] = '\0';
+		fprintf(fout, "common %s\n{\n", cname);
+		for (j=0; common[i].perms[j]; j++)
+			fprintf(fout, "\t%s\n", common[i].perms[j]);
+		fprintf(fout, "}\n\n");
+	}
+	fprintf(fout, "\n");
+
+	/* print out the class permissions */
+	for (i=1; i < classlist_len; i++) {
+		if (classlist[i]) {
+			int firstperm = -1, numperms = 0;
+
+			fprintf(fout, "class %s\n", classlist[i]);
+			/* does it inherit from a common? */
+			for (j=0; j < sizeof(av_inherit)/sizeof(struct av_inherit); j++)
+				if (av_inherit[j].class == i)
+					fprintf(fout, "inherits %s\n", av_inherit[j].common);
+
+			for (j=0; j < sizeof(av_perms)/sizeof(struct av_perms); j++) {
+				if (av_perms[j].class == i) {
+					if (firstperm == -1)
+						firstperm = j;
+					numperms++;
+				}
+			}
+			if (!numperms) {
+				fprintf(fout, "\n");
+				continue;
+			}
+
+			fprintf(fout, "{\n");
+			/* print out the av_perms */
+			for (j=0; j < numperms; j++) {
+				fprintf(fout, "\t%s\n", av_perms[firstperm+j].perm_s);
+			}
+			fprintf(fout, "}\n\n");
+		}
+	}
+	fprintf(fout, "\n");
+
+	/* NOW PRINT OUT MLS STUFF */
+	if (mls) {
+		printf("MLS not yet implemented\n");
+		exit(1);
+	}
+
+	/* types, roles, and allows */
+	fprintf(fout, "type base_t;\n");
+	fprintf(fout, "role base_r types { base_t };\n");
+	for (i=1; i < classlist_len; i++) {
+		if (classlist[i])
+			fprintf(fout, "allow base_t base_t:%s *;\n", classlist[i]);
+		else
+			fprintf(fout, "allow base_t base_t:user%d *;\n", i);
+	}
+	fprintf(fout, "user user_u roles { base_r };\n");
+	fprintf(fout, "\n");
+
+	/* default sids */
+	for (i=1; i < initial_sid_to_string_len; i++)
+		fprintf(fout, "sid %s user_u:base_r:base_t\n", initial_sid_to_string[i]);
+	fprintf(fout, "\n");
+
+
+	fprintf(fout, "fs_use_xattr ext2 user_u:base_r:base_t;\n");
+	fprintf(fout, "fs_use_xattr ext3 user_u:base_r:base_t;\n");
+	fprintf(fout, "fs_use_xattr jfs user_u:base_r:base_t;\n");
+	fprintf(fout, "fs_use_xattr xfs user_u:base_r:base_t;\n");
+	fprintf(fout, "fs_use_xattr reiserfs user_u:base_r:base_t;\n");
+
+	fprintf(fout, "fs_use_task pipefs user_u:base_r:base_t;\n");
+	fprintf(fout, "fs_use_task sockfs user_u:base_r:base_t;\n");
+
+	fprintf(fout, "fs_use_trans devpts user_u:base_r:base_t;\n");
+	fprintf(fout, "fs_use_trans tmpfs user_u:base_r:base_t;\n");
+	fprintf(fout, "fs_use_trans shm user_u:base_r:base_t;\n");
+
+	fprintf(fout, "genfscon proc / user_u:base_r:base_t\n");
+
+	fclose(fout);
+
+	fout = fopen(ctxout, "w");
+	if (!fout) {
+		printf("Wrote policy, but cannot open %s for writing\n", ctxout);
+		usage(argv[0]);
+	}
+	fprintf(fout, "/ user_u:base_r:base_t\n");
+	fprintf(fout, "/.* user_u:base_r:base_t\n");
+	fclose(fout);
+
+	return 0;
+}

security/Kconfig

@@ -51,6 +51,14 @@ config SECURITY
 
 	  If you are unsure how to answer this question, answer N.
 
+config SECURITYFS
+	bool "Enable the securityfs filesystem"
+	help
+	  This will build the securityfs filesystem.  It is currently used by
+	  the TPM bios character driver.  It is not used by SELinux or SMACK.
+
+	  If you are unsure how to answer this question, answer N.
+
 config SECURITY_NETWORK
 	bool "Socket and Networking Security Hooks"
 	depends on SECURITY

security/Makefile

@@ -10,7 +10,8 @@ subdir-$(CONFIG_SECURITY_SMACK)		+= smack
 obj-y		+= commoncap.o
 
 # Object file lists
-obj-$(CONFIG_SECURITY)			+= security.o capability.o inode.o
+obj-$(CONFIG_SECURITY)			+= security.o capability.o
+obj-$(CONFIG_SECURITYFS)		+= inode.o
 # Must precede capability.o in order to stack properly.
 obj-$(CONFIG_SECURITY_SELINUX)		+= selinux/built-in.o
 obj-$(CONFIG_SECURITY_SMACK)		+= smack/built-in.o

security/commoncap.c

@@ -541,7 +541,7 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid,
  * yet with increased caps.
  * So we check for increased caps on the target process.
  */
-static inline int cap_safe_nice(struct task_struct *p)
+static int cap_safe_nice(struct task_struct *p)
 {
 	if (!cap_issubset(p->cap_permitted, current->cap_permitted) &&
 	    !capable(CAP_SYS_NICE))

security/inode.c

@@ -190,7 +190,7 @@ static int create_by_name(const char *name, mode_t mode,
  * @name: a pointer to a string containing the name of the file to create.
  * @mode: the permission that the file should have
  * @parent: a pointer to the parent dentry for this file.  This should be a
- *          directory dentry if set.  If this paramater is NULL, then the
+ *          directory dentry if set.  If this parameter is %NULL, then the
  *          file will be created in the root of the securityfs filesystem.
  * @data: a pointer to something that the caller will want to get to later
  *        on.  The inode.i_private pointer will point to this value on
@@ -199,18 +199,18 @@ static int create_by_name(const char *name, mode_t mode,
  *        this file.
  *
  * This is the basic "create a file" function for securityfs.  It allows for a
- * wide range of flexibility in createing a file, or a directory (if you
+ * wide range of flexibility in creating a file, or a directory (if you
  * want to create a directory, the securityfs_create_dir() function is
- * recommended to be used instead.)
+ * recommended to be used instead).
  *
- * This function will return a pointer to a dentry if it succeeds.  This
+ * This function returns a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the securityfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, NULL will be returned.
+ * you are responsible here).  If an error occurs, %NULL is returned.
  *
- * If securityfs is not enabled in the kernel, the value -ENODEV will be
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
  * returned.  It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
  * code.
  */
 struct dentry *securityfs_create_file(const char *name, mode_t mode,
@@ -252,19 +252,19 @@ EXPORT_SYMBOL_GPL(securityfs_create_file);
  * @name: a pointer to a string containing the name of the directory to
  *        create.
  * @parent: a pointer to the parent dentry for this file.  This should be a
- *          directory dentry if set.  If this paramater is NULL, then the
+ *          directory dentry if set.  If this parameter is %NULL, then the
  *          directory will be created in the root of the securityfs filesystem.
  *
- * This function creates a directory in securityfs with the given name.
+ * This function creates a directory in securityfs with the given @name.
  *
- * This function will return a pointer to a dentry if it succeeds.  This
+ * This function returns a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the securityfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, NULL will be returned.
+ * you are responsible here).  If an error occurs, %NULL will be returned.
  *
- * If securityfs is not enabled in the kernel, the value -ENODEV will be
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
  * returned.  It is not wise to check for this value, but rather, check for
- * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
  * code.
  */
 struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
@@ -278,16 +278,15 @@ EXPORT_SYMBOL_GPL(securityfs_create_dir);
 /**
  * securityfs_remove - removes a file or directory from the securityfs filesystem
  *
- * @dentry: a pointer to a the dentry of the file or directory to be
- *          removed.
+ * @dentry: a pointer to a the dentry of the file or directory to be removed.
  *
  * This function removes a file or directory in securityfs that was previously
  * created with a call to another securityfs function (like
  * securityfs_create_file() or variants thereof.)
  *
  * This function is required to be called in order for the file to be
- * removed, no automatic cleanup of files will happen when a module is
- * removed, you are responsible here.
+ * removed. No automatic cleanup of files will happen when a module is
+ * removed; you are responsible here.
  */
 void securityfs_remove(struct dentry *dentry)
 {

security/security.c

@@ -82,8 +82,8 @@ __setup("security=", choose_lsm);
  *
  * Return true if:
  *	-The passed LSM is the one chosen by user at boot time,
- *	-or user didsn't specify a specific LSM and we're the first to ask
- *	 for registeration permissoin,
+ *	-or user didn't specify a specific LSM and we're the first to ask
+ *	 for registration permission,
  *	-or the passed LSM is currently loaded.
  * Otherwise, return false.
  */
@@ -101,13 +101,13 @@ int __init security_module_enable(struct security_operations *ops)
  * register_security - registers a security framework with the kernel
  * @ops: a pointer to the struct security_options that is to be registered
  *
- * This function is to allow a security module to register itself with the
+ * This function allows a security module to register itself with the
  * kernel security subsystem.  Some rudimentary checking is done on the @ops
  * value passed to this function. You'll need to check first if your LSM
  * is allowed to register its @ops by calling security_module_enable(@ops).
  *
  * If there is already a security module registered with the kernel,
- * an error will be returned.  Otherwise 0 is returned on success.
+ * an error will be returned.  Otherwise %0 is returned on success.
  */
 int register_security(struct security_operations *ops)
 {

security/selinux/Kconfig

@@ -6,9 +6,6 @@ config SECURITY_SELINUX
 	help
 	  This selects NSA Security-Enhanced Linux (SELinux).
 	  You will also need a policy configuration and a labeled filesystem.
-	  You can obtain the policy compiler (checkpolicy), the utility for
-	  labeling filesystems (setfiles), and an example policy configuration
-	  from <http://www.nsa.gov/selinux/>.
 	  If you are unsure how to answer this question, answer N.
 
 config SECURITY_SELINUX_BOOTPARAM

security/selinux/avc.c

@@ -136,7 +136,7 @@ static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
  * @tclass: target security class
  * @av: access vector
  */
-static void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
+void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av)
 {
 	const char **common_pts = NULL;
 	u32 common_base = 0;

security/selinux/hooks.c

@@ -957,7 +957,8 @@ static int superblock_doinit(struct super_block *sb, void *data)
 	return rc;
 }
 
-void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts)
+static void selinux_write_opts(struct seq_file *m,
+			       struct security_mnt_opts *opts)
 {
 	int i;
 	char *prefix;
@@ -1290,7 +1291,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 		/* Default to the fs superblock SID. */
 		isec->sid = sbsec->sid;
 
-		if (sbsec->proc) {
+		if (sbsec->proc && !S_ISLNK(inode->i_mode)) {
 			struct proc_inode *proci = PROC_I(inode);
 			if (proci->pde) {
 				isec->sclass = inode_mode_to_security_class(inode->i_mode);
@@ -3548,38 +3549,44 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
 #endif /* IPV6 */
 
 static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
-			     char **addrp, int src, u8 *proto)
+			     char **_addrp, int src, u8 *proto)
 {
-	int ret = 0;
+	char *addrp;
+	int ret;
 
 	switch (ad->u.net.family) {
 	case PF_INET:
 		ret = selinux_parse_skb_ipv4(skb, ad, proto);
-		if (ret || !addrp)
-			break;
-		*addrp = (char *)(src ? &ad->u.net.v4info.saddr :
+		if (ret)
+			goto parse_error;
+		addrp = (char *)(src ? &ad->u.net.v4info.saddr :
 				       &ad->u.net.v4info.daddr);
-		break;
+		goto okay;
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 	case PF_INET6:
 		ret = selinux_parse_skb_ipv6(skb, ad, proto);
-		if (ret || !addrp)
-			break;
-		*addrp = (char *)(src ? &ad->u.net.v6info.saddr :
+		if (ret)
+			goto parse_error;
+		addrp = (char *)(src ? &ad->u.net.v6info.saddr :
 				       &ad->u.net.v6info.daddr);
-		break;
+		goto okay;
 #endif	/* IPV6 */
 	default:
-		break;
+		addrp = NULL;
+		goto okay;
 	}
 
-	if (unlikely(ret))
+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;
 }
 
 /**
@@ -5219,8 +5226,12 @@ static int selinux_setprocattr(struct task_struct *p,
 
 		if (sid == 0)
 			return -EINVAL;
-
-		/* Only allow single threaded processes to change context */
+		/*
+		 * SELinux allows to change context in the following case only.
+		 *  - Single threaded processes.
+		 *  - Multi threaded processes intend to change its context into
+		 *    more restricted domain (defined by TYPEBOUNDS statement).
+		 */
 		if (atomic_read(&p->mm->mm_users) != 1) {
 			struct task_struct *g, *t;
 			struct mm_struct *mm = p->mm;
@@ -5228,11 +5239,16 @@ static int selinux_setprocattr(struct task_struct *p,
 			do_each_thread(g, t) {
 				if (t->mm == mm && t != p) {
 					read_unlock(&tasklist_lock);
-					return -EPERM;
+					error = security_bounded_transition(tsec->sid, sid);
+					if (!error)
+						goto boundary_ok;
+
+					return error;
 				}
 			} while_each_thread(g, t);
 			read_unlock(&tasklist_lock);
 		}
+boundary_ok:
 
 		/* Check permissions for the transition. */
 		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,

security/selinux/include/avc.h

@@ -12,6 +12,7 @@
 #include <linux/kdev_t.h>
 #include <linux/spinlock.h>
 #include <linux/init.h>
+#include <linux/audit.h>
 #include <linux/in6.h>
 #include <linux/path.h>
 #include <asm/system.h>
@@ -126,6 +127,9 @@ int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
 		     u32 events, u32 ssid, u32 tsid,
 		     u16 tclass, u32 perms);
 
+/* Shows permission in human readable form */
+void avc_dump_av(struct audit_buffer *ab, u16 tclass, u32 av);
+
 /* Exported to selinuxfs */
 int avc_get_hash_stats(char *page);
 extern unsigned int avc_cache_threshold;

security/selinux/include/security.h

@@ -27,13 +27,14 @@
 #define POLICYDB_VERSION_RANGETRANS	21
 #define POLICYDB_VERSION_POLCAP		22
 #define POLICYDB_VERSION_PERMISSIVE	23
+#define POLICYDB_VERSION_BOUNDARY	24
 
 /* Range of policy versions we understand*/
 #define POLICYDB_VERSION_MIN   POLICYDB_VERSION_BASE
 #ifdef CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX
 #define POLICYDB_VERSION_MAX	CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX_VALUE
 #else
-#define POLICYDB_VERSION_MAX	POLICYDB_VERSION_PERMISSIVE
+#define POLICYDB_VERSION_MAX	POLICYDB_VERSION_BOUNDARY
 #endif
 
 #define CONTEXT_MNT	0x01
@@ -62,6 +63,16 @@ enum {
 extern int selinux_policycap_netpeer;
 extern int selinux_policycap_openperm;
 
+/*
+ * type_datum properties
+ * available at the kernel policy version >= POLICYDB_VERSION_BOUNDARY
+ */
+#define TYPEDATUM_PROPERTY_PRIMARY	0x0001
+#define TYPEDATUM_PROPERTY_ATTRIBUTE	0x0002
+
+/* limitation of boundary depth  */
+#define POLICYDB_BOUNDS_MAXDEPTH	4
+
 int security_load_policy(void *data, size_t len);
 
 int security_policycap_supported(unsigned int req_cap);
@@ -117,6 +128,8 @@ int security_node_sid(u16 domain, void *addr, u32 addrlen,
 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 				 u16 tclass);
 
+int security_bounded_transition(u32 oldsid, u32 newsid);
+
 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid);
 
 int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,

security/selinux/ss/avtab.c

@@ -98,7 +98,7 @@ struct avtab_node *
 avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datum *datum)
 {
 	int hvalue;
-	struct avtab_node *prev, *cur, *newnode;
+	struct avtab_node *prev, *cur;
 	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 
 	if (!h || !h->htable)
@@ -122,9 +122,7 @@ avtab_insert_nonunique(struct avtab *h, struct avtab_key *key, struct avtab_datu
 		    key->target_class < cur->key.target_class)
 			break;
 	}
-	newnode = avtab_insert_node(h, hvalue, prev, cur, key, datum);
-
-	return newnode;
+	return avtab_insert_node(h, hvalue, prev, cur, key, datum);
 }
 
 struct avtab_datum *avtab_search(struct avtab *h, struct avtab_key *key)
@@ -231,7 +229,7 @@ void avtab_destroy(struct avtab *h)
 
 	for (i = 0; i < h->nslot; i++) {
 		cur = h->htable[i];
-		while (cur != NULL) {
+		while (cur) {
 			temp = cur;
 			cur = cur->next;
 			kmem_cache_free(avtab_node_cachep, temp);

security/selinux/ss/conditional.c

@@ -29,7 +29,7 @@ static int cond_evaluate_expr(struct policydb *p, struct cond_expr *expr)
 	int s[COND_EXPR_MAXDEPTH];
 	int sp = -1;
 
-	for (cur = expr; cur != NULL; cur = cur->next) {
+	for (cur = expr; cur; cur = cur->next) {
 		switch (cur->expr_type) {
 		case COND_BOOL:
 			if (sp == (COND_EXPR_MAXDEPTH - 1))
@@ -97,14 +97,14 @@ int evaluate_cond_node(struct policydb *p, struct cond_node *node)
 		if (new_state == -1)
 			printk(KERN_ERR "SELinux: expression result was undefined - disabling all rules.\n");
 		/* turn the rules on or off */
-		for (cur = node->true_list; cur != NULL; cur = cur->next) {
+		for (cur = node->true_list; cur; cur = cur->next) {
 			if (new_state <= 0)
 				cur->node->key.specified &= ~AVTAB_ENABLED;
 			else
 				cur->node->key.specified |= AVTAB_ENABLED;
 		}
 
-		for (cur = node->false_list; cur != NULL; cur = cur->next) {
+		for (cur = node->false_list; cur; cur = cur->next) {
 			/* -1 or 1 */
 			if (new_state)
 				cur->node->key.specified &= ~AVTAB_ENABLED;
@@ -128,7 +128,7 @@ int cond_policydb_init(struct policydb *p)
 static void cond_av_list_destroy(struct cond_av_list *list)
 {
 	struct cond_av_list *cur, *next;
-	for (cur = list; cur != NULL; cur = next) {
+	for (cur = list; cur; cur = next) {
 		next = cur->next;
 		/* the avtab_ptr_t node is destroy by the avtab */
 		kfree(cur);
@@ -139,7 +139,7 @@ static void cond_node_destroy(struct cond_node *node)
 {
 	struct cond_expr *cur_expr, *next_expr;
 
-	for (cur_expr = node->expr; cur_expr != NULL; cur_expr = next_expr) {
+	for (cur_expr = node->expr; cur_expr; cur_expr = next_expr) {
 		next_expr = cur_expr->next;
 		kfree(cur_expr);
 	}
@@ -155,7 +155,7 @@ static void cond_list_destroy(struct cond_node *list)
 	if (list == NULL)
 		return;
 
-	for (cur = list; cur != NULL; cur = next) {
+	for (cur = list; cur; cur = next) {
 		next = cur->next;
 		cond_node_destroy(cur);
 	}
@@ -239,7 +239,7 @@ int cond_read_bool(struct policydb *p, struct hashtab *h, void *fp)
 	rc = next_entry(key, fp, len);
 	if (rc < 0)
 		goto err;
-	key[len] = 0;
+	key[len] = '\0';
 	if (hashtab_insert(h, key, booldatum))
 		goto err;
 
@@ -291,7 +291,7 @@ static int cond_insertf(struct avtab *a, struct avtab_key *k, struct avtab_datum
 					goto err;
 				}
 				found = 0;
-				for (cur = other; cur != NULL; cur = cur->next) {
+				for (cur = other; cur; cur = cur->next) {
 					if (cur->node == node_ptr) {
 						found = 1;
 						break;
@@ -485,7 +485,7 @@ void cond_compute_av(struct avtab *ctab, struct avtab_key *key, struct av_decisi
 	if (!ctab || !key || !avd)
 		return;
 
-	for (node = avtab_search_node(ctab, key); node != NULL;
+	for (node = avtab_search_node(ctab, key); node;
 				node = avtab_search_node_next(node, key->specified)) {
 		if ((u16)(AVTAB_ALLOWED|AVTAB_ENABLED) ==
 		    (node->key.specified & (AVTAB_ALLOWED|AVTAB_ENABLED)))

security/selinux/ss/conditional.h

@@ -28,7 +28,7 @@ struct cond_expr {
 #define COND_XOR	5 /* bool ^ bool */
 #define COND_EQ		6 /* bool == bool */
 #define COND_NEQ	7 /* bool != bool */
-#define COND_LAST	8
+#define COND_LAST	COND_NEQ
 	__u32 expr_type;
 	__u32 bool;
 	struct cond_expr *next;

security/selinux/ss/ebitmap.c

@@ -109,7 +109,7 @@ int ebitmap_netlbl_export(struct ebitmap *ebmap,
 	*catmap = c_iter;
 	c_iter->startbit = e_iter->startbit & ~(NETLBL_CATMAP_SIZE - 1);
 
-	while (e_iter != NULL) {
+	while (e_iter) {
 		for (i = 0; i < EBITMAP_UNIT_NUMS; i++) {
 			unsigned int delta, e_startbit, c_endbit;
 
@@ -197,7 +197,7 @@ int ebitmap_netlbl_import(struct ebitmap *ebmap,
 			}
 		}
 		c_iter = c_iter->next;
-	} while (c_iter != NULL);
+	} while (c_iter);
 	if (e_iter != NULL)
 		ebmap->highbit = e_iter->startbit + EBITMAP_SIZE;
 	else

security/selinux/ss/hashtab.c

@@ -81,7 +81,7 @@ void *hashtab_search(struct hashtab *h, const void *key)
 
 	hvalue = h->hash_value(h, key);
 	cur = h->htable[hvalue];
-	while (cur != NULL && h->keycmp(h, key, cur->key) > 0)
+	while (cur && h->keycmp(h, key, cur->key) > 0)
 		cur = cur->next;
 
 	if (cur == NULL || (h->keycmp(h, key, cur->key) != 0))
@@ -100,7 +100,7 @@ void hashtab_destroy(struct hashtab *h)
 
 	for (i = 0; i < h->size; i++) {
 		cur = h->htable[i];
-		while (cur != NULL) {
+		while (cur) {
 			temp = cur;
 			cur = cur->next;
 			kfree(temp);
@@ -127,7 +127,7 @@ int hashtab_map(struct hashtab *h,
 
 	for (i = 0; i < h->size; i++) {
 		cur = h->htable[i];
-		while (cur != NULL) {
+		while (cur) {
 			ret = apply(cur->key, cur->datum, args);
 			if (ret)
 				return ret;

security/selinux/ss/mls.c

@@ -283,8 +283,8 @@ int mls_context_to_sid(struct policydb *pol,
 		p++;
 
 	delim = *p;
-	if (delim != 0)
-		*p++ = 0;
+	if (delim != '\0')
+		*p++ = '\0';
 
 	for (l = 0; l < 2; l++) {
 		levdatum = hashtab_search(pol->p_levels.table, scontextp);
@@ -302,14 +302,14 @@ int mls_context_to_sid(struct policydb *pol,
 				while (*p && *p != ',' && *p != '-')
 					p++;
 				delim = *p;
-				if (delim != 0)
-					*p++ = 0;
+				if (delim != '\0')
+					*p++ = '\0';
 
 				/* Separate into range if exists */
 				rngptr = strchr(scontextp, '.');
 				if (rngptr != NULL) {
 					/* Remove '.' */
-					*rngptr++ = 0;
+					*rngptr++ = '\0';
 				}
 
 				catdatum = hashtab_search(pol->p_cats.table,
@@ -357,8 +357,8 @@ int mls_context_to_sid(struct policydb *pol,
 				p++;
 
 			delim = *p;
-			if (delim != 0)
-				*p++ = 0;
+			if (delim != '\0')
+				*p++ = '\0';
 		} else
 			break;
 	}

security/selinux/ss/policydb.h

@@ -61,6 +61,7 @@ struct class_datum {
 /* Role attributes */
 struct role_datum {
 	u32 value;			/* internal role value */
+	u32 bounds;			/* boundary of role */
 	struct ebitmap dominates;	/* set of roles dominated by this role */
 	struct ebitmap types;		/* set of authorized types for role */
 };
@@ -81,12 +82,15 @@ struct role_allow {
 /* Type attributes */
 struct type_datum {
 	u32 value;		/* internal type value */
+	u32 bounds;		/* boundary of type */
 	unsigned char primary;	/* primary name? */
+	unsigned char attribute;/* attribute ?*/
 };
 
 /* User attributes */
 struct user_datum {
 	u32 value;			/* internal user value */
+	u32 bounds;			/* bounds of user */
 	struct ebitmap roles;		/* set of authorized roles for user */
 	struct mls_range range;		/* MLS range (min - max) for user */
 	struct mls_level dfltlevel;	/* default login MLS level for user */
@@ -209,6 +213,7 @@ struct policydb {
 	struct class_datum **class_val_to_struct;
 	struct role_datum **role_val_to_struct;
 	struct user_datum **user_val_to_struct;
+	struct type_datum **type_val_to_struct;
 
 	/* type enforcement access vectors and transitions */
 	struct avtab te_avtab;

security/selinux/ss/services.c

@@ -88,6 +88,11 @@ static u32 latest_granting;
 static int context_struct_to_string(struct context *context, char **scontext,
 				    u32 *scontext_len);
 
+static int context_struct_compute_av(struct context *scontext,
+				     struct context *tcontext,
+				     u16 tclass,
+				     u32 requested,
+				     struct av_decision *avd);
 /*
  * Return the boolean value of a constraint expression
  * when it is applied to the specified source and target
@@ -273,6 +278,100 @@ static int constraint_expr_eval(struct context *scontext,
 	return s[0];
 }
 
+/*
+ * security_boundary_permission - drops violated permissions
+ * on boundary constraint.
+ */
+static void type_attribute_bounds_av(struct context *scontext,
+				     struct context *tcontext,
+				     u16 tclass,
+				     u32 requested,
+				     struct av_decision *avd)
+{
+	struct context lo_scontext;
+	struct context lo_tcontext;
+	struct av_decision lo_avd;
+	struct type_datum *source
+		= policydb.type_val_to_struct[scontext->type - 1];
+	struct type_datum *target
+		= policydb.type_val_to_struct[tcontext->type - 1];
+	u32 masked = 0;
+
+	if (source->bounds) {
+		memset(&lo_avd, 0, sizeof(lo_avd));
+
+		memcpy(&lo_scontext, scontext, sizeof(lo_scontext));
+		lo_scontext.type = source->bounds;
+
+		context_struct_compute_av(&lo_scontext,
+					  tcontext,
+					  tclass,
+					  requested,
+					  &lo_avd);
+		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
+			return;		/* no masked permission */
+		masked = ~lo_avd.allowed & avd->allowed;
+	}
+
+	if (target->bounds) {
+		memset(&lo_avd, 0, sizeof(lo_avd));
+
+		memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext));
+		lo_tcontext.type = target->bounds;
+
+		context_struct_compute_av(scontext,
+					  &lo_tcontext,
+					  tclass,
+					  requested,
+					  &lo_avd);
+		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
+			return;		/* no masked permission */
+		masked = ~lo_avd.allowed & avd->allowed;
+	}
+
+	if (source->bounds && target->bounds) {
+		memset(&lo_avd, 0, sizeof(lo_avd));
+		/*
+		 * lo_scontext and lo_tcontext are already
+		 * set up.
+		 */
+
+		context_struct_compute_av(&lo_scontext,
+					  &lo_tcontext,
+					  tclass,
+					  requested,
+					  &lo_avd);
+		if ((lo_avd.allowed & avd->allowed) == avd->allowed)
+			return;		/* no masked permission */
+		masked = ~lo_avd.allowed & avd->allowed;
+	}
+
+	if (masked) {
+		struct audit_buffer *ab;
+		char *stype_name
+			= policydb.p_type_val_to_name[source->value - 1];
+		char *ttype_name
+			= policydb.p_type_val_to_name[target->value - 1];
+		char *tclass_name
+			= policydb.p_class_val_to_name[tclass - 1];
+
+		/* mask violated permissions */
+		avd->allowed &= ~masked;
+
+		/* notice to userspace via audit message */
+		ab = audit_log_start(current->audit_context,
+				     GFP_ATOMIC, AUDIT_SELINUX_ERR);
+		if (!ab)
+			return;
+
+		audit_log_format(ab, "av boundary violation: "
+				 "source=%s target=%s tclass=%s",
+				 stype_name, ttype_name, tclass_name);
+		avc_dump_av(ab, tclass, masked);
+		audit_log_end(ab);
+	}
+}
+
 /*
  * Compute access vectors based on a context structure pair for
  * the permissions in a particular class.
@@ -356,7 +455,7 @@ static int context_struct_compute_av(struct context *scontext,
 			avkey.source_type = i + 1;
 			avkey.target_type = j + 1;
 			for (node = avtab_search_node(&policydb.te_avtab, &avkey);
-			     node != NULL;
+			     node;
 			     node = avtab_search_node_next(node, avkey.specified)) {
 				if (node->key.specified == AVTAB_ALLOWED)
 					avd->allowed |= node->datum.data;
@@ -404,6 +503,14 @@ static int context_struct_compute_av(struct context *scontext,
 							PROCESS__DYNTRANSITION);
 	}
 
+	/*
+	 * If the given source and target types have boundary
+	 * constraint, lazy checks have to mask any violated
+	 * permission and notice it to userspace via audit.
+	 */
+	type_attribute_bounds_av(scontext, tcontext,
+				 tclass, requested, avd);
+
 	return 0;
 
 inval_class:
@@ -549,6 +656,69 @@ int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 	return rc;
 }
 
+/*
+ * security_bounded_transition - check whether the given
+ * transition is directed to bounded, or not.
+ * It returns 0, if @newsid is bounded by @oldsid.
+ * Otherwise, it returns error code.
+ *
+ * @oldsid : current security identifier
+ * @newsid : destinated security identifier
+ */
+int security_bounded_transition(u32 old_sid, u32 new_sid)
+{
+	struct context *old_context, *new_context;
+	struct type_datum *type;
+	int index;
+	int rc = -EINVAL;
+
+	read_lock(&policy_rwlock);
+
+	old_context = sidtab_search(&sidtab, old_sid);
+	if (!old_context) {
+		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
+		       __func__, old_sid);
+		goto out;
+	}
+
+	new_context = sidtab_search(&sidtab, new_sid);
+	if (!new_context) {
+		printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n",
+		       __func__, new_sid);
+		goto out;
+	}
+
+	/* type/domain unchaned */
+	if (old_context->type == new_context->type) {
+		rc = 0;
+		goto out;
+	}
+
+	index = new_context->type;
+	while (true) {
+		type = policydb.type_val_to_struct[index - 1];
+		BUG_ON(!type);
+
+		/* not bounded anymore */
+		if (!type->bounds) {
+			rc = -EPERM;
+			break;
+		}
+
+		/* @newsid is bounded by @oldsid */
+		if (type->bounds == old_context->type) {
+			rc = 0;
+			break;
+		}
+		index = type->bounds;
+	}
+out:
+	read_unlock(&policy_rwlock);
+
+	return rc;
+}
+
+
 /**
  * security_compute_av - Compute access vector decisions.
  * @ssid: source security identifier
@@ -794,7 +964,7 @@ static int string_to_context_struct(struct policydb *pol,
 	*p++ = 0;
 
 	typdatum = hashtab_search(pol->p_types.table, scontextp);
-	if (!typdatum)
+	if (!typdatum || typdatum->attribute)
 		goto out;
 
 	ctx->type = typdatum->value;
@@ -1037,7 +1207,7 @@ static int security_compute_sid(u32 ssid,
 	/* If no permanent rule, also check for enabled conditional rules */
 	if (!avdatum) {
 		node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
-		for (; node != NULL; node = avtab_search_node_next(node, specified)) {
+		for (; node; node = avtab_search_node_next(node, specified)) {
 			if (node->key.specified & AVTAB_ENABLED) {
 				avdatum = &node->datum;
 				break;
@@ -2050,7 +2220,7 @@ int security_set_bools(int len, int *values)
 			policydb.bool_val_to_struct[i]->state = 0;
 	}
 
-	for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
+	for (cur = policydb.cond_list; cur; cur = cur->next) {
 		rc = evaluate_cond_node(&policydb, cur);
 		if (rc)
 			goto out;
@@ -2102,7 +2272,7 @@ static int security_preserve_bools(struct policydb *p)
 		if (booldatum)
 			booldatum->state = bvalues[i];
 	}
-	for (cur = p->cond_list; cur != NULL; cur = cur->next) {
+	for (cur = p->cond_list; cur; cur = cur->next) {
 		rc = evaluate_cond_node(p, cur);
 		if (rc)
 			goto out;

security/selinux/ss/sidtab.c

@@ -43,7 +43,7 @@ int sidtab_insert(struct sidtab *s, u32 sid, struct context *context)
 	hvalue = SIDTAB_HASH(sid);
 	prev = NULL;
 	cur = s->htable[hvalue];
-	while (cur != NULL && sid > cur->sid) {
+	while (cur && sid > cur->sid) {
 		prev = cur;
 		cur = cur->next;
 	}
@@ -92,7 +92,7 @@ static struct context *sidtab_search_core(struct sidtab *s, u32 sid, int force)
 
 	hvalue = SIDTAB_HASH(sid);
 	cur = s->htable[hvalue];
-	while (cur != NULL && sid > cur->sid)
+	while (cur && sid > cur->sid)
 		cur = cur->next;
 
 	if (force && cur && sid == cur->sid && cur->context.len)
@@ -103,7 +103,7 @@ static struct context *sidtab_search_core(struct sidtab *s, u32 sid, int force)
 		sid = SECINITSID_UNLABELED;
 		hvalue = SIDTAB_HASH(sid);
 		cur = s->htable[hvalue];
-		while (cur != NULL && sid > cur->sid)
+		while (cur && sid > cur->sid)
 			cur = cur->next;
 		if (!cur || sid != cur->sid)
 			return NULL;
@@ -136,7 +136,7 @@ int sidtab_map(struct sidtab *s,
 
 	for (i = 0; i < SIDTAB_SIZE; i++) {
 		cur = s->htable[i];
-		while (cur != NULL) {
+		while (cur) {
 			rc = apply(cur->sid, &cur->context, args);
 			if (rc)
 				goto out;
@@ -155,7 +155,7 @@ static inline u32 sidtab_search_context(struct sidtab *s,
 
 	for (i = 0; i < SIDTAB_SIZE; i++) {
 		cur = s->htable[i];
-		while (cur != NULL) {
+		while (cur) {
 			if (context_cmp(&cur->context, context))
 				return cur->sid;
 			cur = cur->next;
@@ -242,7 +242,7 @@ void sidtab_destroy(struct sidtab *s)
 
 	for (i = 0; i < SIDTAB_SIZE; i++) {
 		cur = s->htable[i];
-		while (cur != NULL) {
+		while (cur) {
 			temp = cur;
 			cur = cur->next;
 			context_destroy(&temp->context);

security/smack/smack.h

@@ -178,6 +178,7 @@ u32 smack_to_secid(const char *);
 extern int smack_cipso_direct;
 extern int smack_net_nltype;
 extern char *smack_net_ambient;
+extern char *smack_onlycap;
 
 extern struct smack_known *smack_known;
 extern struct smack_known smack_known_floor;

security/smack/smack_access.c

@@ -157,7 +157,7 @@ int smk_access(char *subject_label, char *object_label, int request)
  *
  * This function checks the current subject label/object label pair
  * in the access rule list and returns 0 if the access is permitted,
- * non zero otherwise. It allows that current my have the capability
+ * non zero otherwise. It allows that current may have the capability
  * to override the rules.
  */
 int smk_curacc(char *obj_label, u32 mode)
@@ -168,6 +168,14 @@ int smk_curacc(char *obj_label, u32 mode)
 	if (rc == 0)
 		return 0;
 
+	/*
+	 * Return if a specific label has been designated as the
+	 * only one that gets privilege and current does not
+	 * have that label.
+	 */
+	if (smack_onlycap != NULL && smack_onlycap != current->security)
+		return rc;
+
 	if (capable(CAP_MAC_OVERRIDE))
 		return 0;
 

security/smack/smackfs.c

@@ -39,6 +39,7 @@ enum smk_inos {
 	SMK_DIRECT	= 6,	/* CIPSO level indicating direct label */
 	SMK_AMBIENT	= 7,	/* internet ambient label */
 	SMK_NLTYPE	= 8,	/* label scheme to use by default */
+	SMK_ONLYCAP	= 9,	/* the only "capable" label */
 };
 
 /*
@@ -68,6 +69,16 @@ int smack_net_nltype = NETLBL_NLTYPE_CIPSOV4;
  */
 int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT;
 
+/*
+ * Unless a process is running with this label even
+ * having CAP_MAC_OVERRIDE isn't enough to grant
+ * privilege to violate MAC policy. If no label is
+ * designated (the NULL case) capabilities apply to
+ * everyone. It is expected that the hat (^) label
+ * will be used if any label is used.
+ */
+char *smack_onlycap;
+
 static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
 struct smk_list_entry *smack_list;
 
@@ -787,6 +798,85 @@ static const struct file_operations smk_ambient_ops = {
 	.write		= smk_write_ambient,
 };
 
+/**
+ * smk_read_onlycap - read() for /smack/onlycap
+ * @filp: file pointer, not actually used
+ * @buf: where to put the result
+ * @cn: maximum to send along
+ * @ppos: where to start
+ *
+ * Returns number of bytes read or error code, as appropriate
+ */
+static ssize_t smk_read_onlycap(struct file *filp, char __user *buf,
+				size_t cn, loff_t *ppos)
+{
+	char *smack = "";
+	ssize_t rc = -EINVAL;
+	int asize;
+
+	if (*ppos != 0)
+		return 0;
+
+	if (smack_onlycap != NULL)
+		smack = smack_onlycap;
+
+	asize = strlen(smack) + 1;
+
+	if (cn >= asize)
+		rc = simple_read_from_buffer(buf, cn, ppos, smack, asize);
+
+	return rc;
+}
+
+/**
+ * smk_write_onlycap - write() for /smack/onlycap
+ * @filp: file pointer, not actually used
+ * @buf: where to get the data from
+ * @count: bytes sent
+ * @ppos: where to start
+ *
+ * Returns number of bytes written or error code, as appropriate
+ */
+static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	char in[SMK_LABELLEN];
+	char *sp = current->security;
+
+	if (!capable(CAP_MAC_ADMIN))
+		return -EPERM;
+
+	/*
+	 * This can be done using smk_access() but is done
+	 * explicitly for clarity. The smk_access() implementation
+	 * would use smk_access(smack_onlycap, MAY_WRITE)
+	 */
+	if (smack_onlycap != NULL && smack_onlycap != sp)
+		return -EPERM;
+
+	if (count >= SMK_LABELLEN)
+		return -EINVAL;
+
+	if (copy_from_user(in, buf, count) != 0)
+		return -EFAULT;
+
+	/*
+	 * Should the null string be passed in unset the onlycap value.
+	 * This seems like something to be careful with as usually
+	 * smk_import only expects to return NULL for errors. It
+	 * is usually the case that a nullstring or "\n" would be
+	 * bad to pass to smk_import but in fact this is useful here.
+	 */
+	smack_onlycap = smk_import(in, count);
+
+	return count;
+}
+
+static const struct file_operations smk_onlycap_ops = {
+	.read		= smk_read_onlycap,
+	.write		= smk_write_onlycap,
+};
+
 struct option_names {
 	int	o_number;
 	char	*o_name;
@@ -919,6 +1009,8 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
 			{"ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR},
 		[SMK_NLTYPE]	=
 			{"nltype", &smk_nltype_ops, S_IRUGO|S_IWUSR},
+		[SMK_ONLYCAP]	=
+			{"onlycap", &smk_onlycap_ops, S_IRUGO|S_IWUSR},
 		/* last one */ {""}
 	};