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    Subject[AppArmor 40/45] AppArmor: all the rest
    All the things that didn't nicely fit in a category on their own: kbuild
    code, declararions and inline functions, /sys/kernel/security/apparmor
    filesystem for controlling apparmor from user space, profile list
    functions, locking documentation, /proc/$pid/task/$tid/attr/current
    access.

    Signed-off-by: John Johansen <jjohansen@suse.de>
    Signed-off-by: Andreas Gruenbacher <agruen@suse.de>

    ---
    security/apparmor/Kconfig | 9 +
    security/apparmor/Makefile | 13 ++
    security/apparmor/apparmor.h | 259 +++++++++++++++++++++++++++++++++++++++++
    security/apparmor/apparmorfs.c | 250 +++++++++++++++++++++++++++++++++++++++
    security/apparmor/inline.h | 219 ++++++++++++++++++++++++++++++++++
    security/apparmor/list.c | 94 ++++++++++++++
    security/apparmor/locking.txt | 59 +++++++++
    security/apparmor/procattr.c | 138 +++++++++++++++++++++
    8 files changed, 1041 insertions(+)

    --- /dev/null
    +++ b/security/apparmor/Kconfig
    @@ -0,0 +1,9 @@
    +config SECURITY_APPARMOR
    + tristate "AppArmor support"
    + depends on SECURITY!=n
    + help
    + This enables the AppArmor security module.
    + Required userspace tools (if they are not included in your
    + distribution) and further information may be found at
    + <http://forge.novell.com/modules/xfmod/project/?apparmor>
    + If you are unsure how to answer this question, answer N.
    --- /dev/null
    +++ b/security/apparmor/Makefile
    @@ -0,0 +1,13 @@
    +# Makefile for AppArmor Linux Security Module
    +#
    +obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o
    +
    +apparmor-y := main.o list.o procattr.o lsm.o apparmorfs.o \
    + module_interface.o match.o
    +
    +quiet_cmd_make-caps = GEN $@
    +cmd_make-caps = sed -n -e "/CAP_FS_MASK/d" -e "s/^\#define[ \\t]\\+CAP_\\([A-Z0-9_]\\+\\)[ \\t]\\+\\([0-9]\\+\\)\$$/[\\2] = \"\\1\",/p" $< | tr A-Z a-z > $@
    +
    +$(obj)/main.o : $(obj)/capability_names.h
    +$(obj)/capability_names.h : $(srctree)/include/linux/capability.h
    + $(call cmd,make-caps)
    --- /dev/null
    +++ b/security/apparmor/apparmor.h
    @@ -0,0 +1,259 @@
    +/*
    + * Copyright (C) 1998-2007 Novell/SUSE
    + *
    + * 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, version 2 of the
    + * License.
    + *
    + * AppArmor internal prototypes
    + */
    +
    +#ifndef __APPARMOR_H
    +#define __APPARMOR_H
    +
    +#include <linux/sched.h>
    +#include <linux/fs.h>
    +#include <linux/binfmts.h>
    +#include <linux/rcupdate.h>
    +
    +/*
    + * We use MAY_READ, MAY_WRITE, MAY_EXEC, and the following flags for
    + * profile permissions (we don't use MAY_APPEND):
    + */
    +#define AA_MAY_LINK 0x0010
    +#define AA_EXEC_INHERIT 0x0020
    +#define AA_EXEC_UNCONFINED 0x0040
    +#define AA_EXEC_PROFILE 0x0080
    +#define AA_EXEC_MMAP 0x0100
    +#define AA_EXEC_UNSAFE 0x0200
    +
    +#define AA_EXEC_MODIFIERS (AA_EXEC_INHERIT | \
    + AA_EXEC_UNCONFINED | \
    + AA_EXEC_PROFILE)
    +
    +#define AA_SECURE_EXEC_NEEDED 1
    +
    +/* Control parameters (0 or 1), settable thru module/boot flags or
    + * via /sys/kernel/security/apparmor/control */
    +extern int apparmor_complain;
    +extern int apparmor_debug;
    +extern int apparmor_audit;
    +extern int apparmor_logsyscall;
    +extern unsigned int apparmor_path_max;
    +
    +#define PROFILE_COMPLAIN(_profile) \
    + (apparmor_complain == 1 || ((_profile) && (_profile)->flags.complain))
    +
    +#define APPARMOR_COMPLAIN(_cxt) \
    + (apparmor_complain == 1 || \
    + ((_cxt) && (_cxt)->profile && (_cxt)->profile->flags.complain))
    +
    +#define PROFILE_AUDIT(_profile) \
    + (apparmor_audit == 1 || ((_profile) && (_profile)->flags.audit))
    +
    +#define APPARMOR_AUDIT(_cxt) \
    + (apparmor_audit == 1 || \
    + ((_cxt) && (_cxt)->profile && (_cxt)->profile->flags.audit))
    +
    +/*
    + * DEBUG remains global (no per profile flag) since it is mostly used in sysctl
    + * which is not related to profile accesses.
    + */
    +
    +#define AA_DEBUG(fmt, args...) \
    + do { \
    + if (apparmor_debug) \
    + printk(KERN_DEBUG "AppArmor: " fmt, ##args); \
    + } while (0)
    +
    +#define AA_ERROR(fmt, args...) printk(KERN_ERR "AppArmor: " fmt, ##args)
    +
    +/* struct aa_profile - basic confinement data
    + * @parent: non refcounted pointer to parent profile
    + * @name: the profiles name
    + * @file_rules: dfa containing the profiles file rules
    + * @list: list this profile is on
    + * @sub: profiles list of subprofiles (HATS)
    + * @flags: flags controlling profile behavior
    + * @null_profile: if needed per profile learning and null confinement profile
    + * @isstale: flag indicating if profile is stale
    + * @capabilities: capabilities granted by the process
    + * @count: reference count of the profile
    + *
    + * The AppArmor profile contains the basic confinement data. Each profile
    + * has a name and potentially a list of sub profile entries. All non stale
    + * profiles are on the profile_list.
    + *
    + * The task_contexts list and the isstale flag are protected by the
    + * profile lock.
    + *
    + * If a task context is moved between two profiles, we first need to grab
    + * both profile locks. lock_both_profiles() does that in a deadlock-safe
    + * way.
    + */
    +struct aa_profile {
    + struct aa_profile *parent;
    + char *name;
    + struct aa_dfa *file_rules;
    + struct list_head list;
    + struct list_head sub;
    + struct {
    + int complain;
    + int audit;
    + } flags;
    + struct aa_profile *null_profile;
    + int isstale;
    +
    + kernel_cap_t capabilities;
    + struct kref count;
    + struct list_head task_contexts;
    + spinlock_t lock;
    + unsigned long int_flags;
    +};
    +
    +extern struct list_head profile_list;
    +extern rwlock_t profile_list_lock;
    +extern struct mutex aa_interface_lock;
    +
    +/**
    + * struct aa_task_context - primary label for confined tasks
    + * @profile: the current profile
    + * @hat_magic: the magic token controling the ability to leave a hat
    + * @list: list this aa_task_context is on
    + * @task: task that the aa_task_context confines
    + * @rcu: rcu head used when freeing the aa_task_context
    + * @caps_logged: caps that have previously generated log entries
    + *
    + * Contains the task's current profile (which could change due to
    + * change_hat). Plus the hat_magic needed during change_hat.
    + */
    +struct aa_task_context {
    + struct aa_profile *profile; /* The current profile */
    + u64 hat_magic; /* used with change_hat */
    + struct list_head list;
    + struct task_struct *task;
    + struct rcu_head rcu;
    + kernel_cap_t caps_logged;
    +};
    +
    +extern struct aa_profile *null_complain_profile;
    +
    +/* aa_audit - AppArmor auditing structure
    + * Structure is populated by access control code and passed to aa_audit which
    + * provides for a single point of logging.
    + */
    +
    +struct aa_audit {
    + unsigned short type, flags;
    + unsigned int result;
    + gfp_t gfp_mask;
    + int error_code;
    + const char *name;
    + char *buffer;
    + union {
    + int mask;
    + int capability;
    + struct {
    + const char *name2;
    + char *buffer2;
    + };
    + struct iattr *iattr;
    + va_list vaval;
    + };
    +};
    +
    +/* audit types */
    +#define AA_MANGLE_NAME 32
    +#define AA_MANGLE_NAME2 64
    +#define AA_AUDITTYPE_FILE (1 | AA_MANGLE_NAME)
    +#define AA_AUDITTYPE_DIR (2 | AA_MANGLE_NAME)
    +#define AA_AUDITTYPE_ATTR (3 | AA_MANGLE_NAME)
    +#define AA_AUDITTYPE_XATTR (4 | AA_MANGLE_NAME)
    +#define AA_AUDITTYPE_LINK (5 | AA_MANGLE_NAME | AA_MANGLE_NAME2)
    +#define AA_AUDITTYPE_CAP 6
    +#define AA_AUDITTYPE_MSG 7
    +#define AA_AUDITTYPE_SYSCALL 8
    +
    +/* audit flags */
    +#define AA_AUDITFLAG_AUDITSS_SYSCALL 1 /* log syscall context */
    +#define AA_AUDITFLAG_LOGERR 2 /* log operations that failed due to
    + non permission errors */
    +
    +/* Flags for the permission check functions */
    +#define AA_CHECK_FD 1 /* coming from a file descriptor */
    +#define AA_CHECK_DIR 2 /* file type is directory */
    +#define AA_CHECK_MANGLE 4 /* leave extra room for name mangling */
    +
    +/* main.c */
    +extern int alloc_null_complain_profile(void);
    +extern void free_null_complain_profile(void);
    +extern int attach_nullprofile(struct aa_profile *profile);
    +extern int aa_audit_message(struct aa_profile *profile, gfp_t gfp,
    + const char *, ...)
    + __attribute__ ((format (printf, 3, 4)));
    +extern int aa_audit_syscallreject(struct aa_profile *profile, gfp_t gfp,
    + const char *);
    +extern int aa_audit(struct aa_profile *profile, struct aa_audit *);
    +
    +extern int aa_attr(struct aa_profile *profile, struct dentry *dentry,
    + struct vfsmount *mnt, struct iattr *iattr);
    +extern int aa_perm_xattr(struct aa_profile *profile, struct dentry *dentry,
    + struct vfsmount *mnt, const char *operation, int mask,
    + int check);
    +extern int aa_capability(struct aa_task_context *cxt, int cap);
    +extern int aa_perm(struct aa_profile *profile, struct dentry *dentry,
    + struct vfsmount *mnt, int mask, int check);
    +extern int aa_perm_dir(struct aa_profile *profile, struct dentry *dentry,
    + struct vfsmount *mnt, const char *operation, int mask);
    +extern int aa_perm_path(struct aa_profile *, const char *, int);
    +extern int aa_link(struct aa_profile *profile,
    + struct dentry *link, struct vfsmount *link_mnt,
    + struct dentry *target, struct vfsmount *target_mnt);
    +extern int aa_clone(struct task_struct *task);
    +extern int aa_register(struct linux_binprm *bprm);
    +extern void aa_release(struct task_struct *task);
    +extern int aa_change_hat(const char *id, u64 hat_magic);
    +extern struct aa_profile *__aa_find_profile(const char *name,
    + struct list_head *list);
    +extern struct aa_profile *__aa_replace_profile(struct task_struct *task,
    + struct aa_profile *profile,
    + u32 hat_magic);
    +extern struct aa_task_context *lock_task_and_profiles(struct task_struct *task,
    + struct aa_profile *profile);
    +extern void aa_change_task_context(struct task_struct *task,
    + struct aa_task_context *new_cxt,
    + struct aa_profile *profile, u64 hat_magic);
    +extern int aa_may_ptrace(struct aa_task_context *cxt,
    + struct aa_profile *tracee);
    +
    +/* list.c */
    +extern void aa_profilelist_release(void);
    +
    +/* module_interface.c */
    +extern ssize_t aa_add_profile(void *, size_t);
    +extern ssize_t aa_replace_profile(void *, size_t);
    +extern ssize_t aa_remove_profile(const char *, size_t);
    +extern struct aa_profile *alloc_aa_profile(void);
    +extern void free_aa_profile(struct aa_profile *profile);
    +extern void free_aa_profile_kref(struct kref *kref);
    +extern void aa_unconfine_tasks(struct aa_profile *profile);
    +
    +/* procattr.c */
    +extern int aa_getprocattr(struct aa_profile *profile, char **string,
    + unsigned *len);
    +extern int aa_setprocattr_changehat(char *args);
    +extern int aa_setprocattr_setprofile(struct task_struct *task, char *args);
    +
    +/* apparmorfs.c */
    +extern int create_apparmorfs(void);
    +extern void destroy_apparmorfs(void);
    +
    +/* match.c */
    +extern struct aa_dfa *aa_match_alloc(void);
    +extern void aa_match_free(struct aa_dfa *dfa);
    +extern int unpack_dfa(struct aa_dfa *dfa, void *blob, size_t size);
    +extern int verify_dfa(struct aa_dfa *dfa);
    +extern unsigned int aa_dfa_match(struct aa_dfa *dfa, const char *str);
    +
    +#endif /* __APPARMOR_H */
    --- /dev/null
    +++ b/security/apparmor/apparmorfs.c
    @@ -0,0 +1,250 @@
    +/*
    + * Copyright (C) 1998-2007 Novell/SUSE
    + *
    + * 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, version 2 of the
    + * License.
    + *
    + * AppArmor filesystem (part of securityfs)
    + */
    +
    +#include <linux/security.h>
    +#include <linux/vmalloc.h>
    +#include <linux/module.h>
    +#include <linux/seq_file.h>
    +#include <asm/uaccess.h>
    +
    +#include "apparmor.h"
    +#include "inline.h"
    +
    +static char *aa_simple_write_to_buffer(const char __user *userbuf,
    + size_t alloc_size, size_t copy_size,
    + loff_t *pos, const char *msg)
    +{
    + struct aa_profile *profile;
    + char *data;
    +
    + if (*pos != 0) {
    + /* only writes from pos 0, that is complete writes */
    + data = ERR_PTR(-ESPIPE);
    + goto out;
    + }
    +
    + /*
    + * Don't allow confined processes to load/replace/remove profiles.
    + * No sane person would add rules allowing this to a profile
    + * but we enforce the restriction anyways.
    + */
    + profile = aa_get_profile(current);
    + if (profile) {
    + aa_audit_message(NULL, GFP_KERNEL, "REJECTING access to "
    + "profile %s (%d profile %s active %s)",
    + msg, current->pid, profile->parent->name,
    + profile->name);
    + aa_put_profile(profile);
    +
    + data = ERR_PTR(-EPERM);
    + goto out;
    + }
    +
    + data = vmalloc(alloc_size);
    + if (data == NULL) {
    + data = ERR_PTR(-ENOMEM);
    + goto out;
    + }
    +
    + if (copy_from_user(data, userbuf, copy_size)) {
    + vfree(data);
    + data = ERR_PTR(-EFAULT);
    + goto out;
    + }
    +
    +out:
    + return data;
    +}
    +
    +/* apparmor/profiles */
    +extern struct seq_operations apparmorfs_profiles_op;
    +
    +static int aa_profiles_open(struct inode *inode, struct file *file)
    +{
    + return seq_open(file, &apparmorfs_profiles_op);
    +}
    +
    +
    +static int aa_profiles_release(struct inode *inode, struct file *file)
    +{
    + return seq_release(inode, file);
    +}
    +
    +static struct file_operations apparmorfs_profiles_fops = {
    + .open = aa_profiles_open,
    + .read = seq_read,
    + .llseek = seq_lseek,
    + .release = aa_profiles_release,
    +};
    +
    +/* apparmor/matching */
    +static ssize_t aa_matching_read(struct file *file, char __user *buf,
    + size_t size, loff_t *ppos)
    +{
    + const char *matching = "pattern=aadfa";
    +
    + return simple_read_from_buffer(buf, size, ppos, matching,
    + strlen(matching));
    +}
    +
    +static struct file_operations apparmorfs_matching_fops = {
    + .read = aa_matching_read,
    +};
    +
    +/* apparmor/.load */
    +static ssize_t aa_profile_load(struct file *f, const char __user *buf,
    + size_t size, loff_t *pos)
    +{
    + char *data;
    + ssize_t error;
    +
    + data = aa_simple_write_to_buffer(buf, size, size, pos, "load");
    +
    + error = PTR_ERR(data);
    + if (!IS_ERR(data)) {
    + error = aa_add_profile(data, size);
    + vfree(data);
    + }
    +
    + return error;
    +}
    +
    +
    +static struct file_operations apparmorfs_profile_load = {
    + .write = aa_profile_load
    +};
    +
    +/* apparmor/.replace */
    +static ssize_t aa_profile_replace(struct file *f, const char __user *buf,
    + size_t size, loff_t *pos)
    +{
    + char *data;
    + ssize_t error;
    +
    + data = aa_simple_write_to_buffer(buf, size, size, pos, "replacement");
    +
    + error = PTR_ERR(data);
    + if (!IS_ERR(data)) {
    + error = aa_replace_profile(data, size);
    + vfree(data);
    + }
    +
    + return error;
    +}
    +
    +
    +static struct file_operations apparmorfs_profile_replace = {
    + .write = aa_profile_replace
    +};
    +
    +/* apparmor/.remove */
    +static ssize_t aa_profile_remove(struct file *f, const char __user *buf,
    + size_t size, loff_t *pos)
    +{
    + char *data;
    + ssize_t error;
    +
    + /*
    + * aa_remove_profile needs a null terminated string so 1 extra
    + * byte is allocated and the copied data is null terminated.
    + */
    + data = aa_simple_write_to_buffer(buf, size + 1, size, pos, "removal");
    +
    + error = PTR_ERR(data);
    + if (!IS_ERR(data)) {
    + data[size] = 0;
    + error = aa_remove_profile(data, size);
    + vfree(data);
    + }
    +
    + return error;
    +}
    +
    +static struct file_operations apparmorfs_profile_remove = {
    + .write = aa_profile_remove
    +};
    +
    +static struct dentry *apparmor_dentry;
    +
    +static void aafs_remove(const char *name)
    +{
    + struct dentry *dentry;
    +
    + dentry = lookup_one_len(name, apparmor_dentry, strlen(name));
    + if (!IS_ERR(dentry)) {
    + securityfs_remove(dentry);
    + dput(dentry);
    + }
    +}
    +
    +static int aafs_create(const char *name, int mask, struct file_operations *fops)
    +{
    + struct dentry *dentry;
    +
    + dentry = securityfs_create_file(name, S_IFREG | mask, apparmor_dentry,
    + NULL, fops);
    +
    + return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
    +}
    +
    +void destroy_apparmorfs(void)
    +{
    + if (apparmor_dentry) {
    + aafs_remove(".remove");
    + aafs_remove(".replace");
    + aafs_remove(".load");
    + aafs_remove("matching");
    + aafs_remove("profiles");
    + securityfs_remove(apparmor_dentry);
    + apparmor_dentry = NULL;
    + }
    +}
    +
    +int create_apparmorfs(void)
    +{
    + int error;
    +
    + if (apparmor_dentry) {
    + AA_ERROR("%s: AppArmor securityfs already exists\n",
    + __FUNCTION__);
    + return -EEXIST;
    + }
    +
    + apparmor_dentry = securityfs_create_dir("apparmor", NULL);
    + if (IS_ERR(apparmor_dentry)) {
    + error = PTR_ERR(apparmor_dentry);
    + apparmor_dentry = NULL;
    + goto error;
    + }
    + error = aafs_create("profiles", 0440, &apparmorfs_profiles_fops);
    + if (error)
    + goto error;
    + error = aafs_create("matching", 0444, &apparmorfs_matching_fops);
    + if (error)
    + goto error;
    + error = aafs_create(".load", 0640, &apparmorfs_profile_load);
    + if (error)
    + goto error;
    + error = aafs_create(".replace", 0640, &apparmorfs_profile_replace);
    + if (error)
    + goto error;
    + error = aafs_create(".remove", 0640, &apparmorfs_profile_remove);
    + if (error)
    + goto error;
    +
    + return 0;
    +
    +error:
    + destroy_apparmorfs();
    + AA_ERROR("Error creating AppArmor securityfs\n");
    + return error;
    +}
    +
    --- /dev/null
    +++ b/security/apparmor/inline.h
    @@ -0,0 +1,219 @@
    +/*
    + * Copyright (C) 1998-2007 Novell/SUSE
    + *
    + * 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, version 2 of the
    + * License.
    + */
    +
    +#ifndef __INLINE_H
    +#define __INLINE_H
    +
    +#include <linux/sched.h>
    +
    +static inline int mediated_filesystem(struct inode *inode)
    +{
    + return !(inode->i_sb->s_flags & MS_NOUSER);
    +}
    +
    +static inline struct aa_task_context *aa_task_context(struct task_struct *task)
    +{
    + return rcu_dereference((struct aa_task_context *)task->security);
    +}
    +
    +/**
    + * aa_dup_profile - increment refcount on profile @p
    + * @p: profile
    + */
    +static inline struct aa_profile *aa_dup_profile(struct aa_profile *p)
    +{
    + if (p)
    + kref_get(&(p->parent->count));
    +
    + return p;
    +}
    +
    +/**
    + * aa_put_profile - decrement refcount on profile @p
    + * @p: profile
    + */
    +static inline void aa_put_profile(struct aa_profile *p)
    +{
    + if (p)
    + kref_put(&p->parent->count, free_aa_profile_kref);
    +}
    +
    +static inline struct aa_profile *aa_get_profile(struct task_struct *task)
    +{
    + struct aa_task_context *cxt;
    + struct aa_profile *profile = NULL;
    +
    + rcu_read_lock();
    + cxt = aa_task_context(task);
    + if (cxt) {
    + profile = cxt->profile;
    + aa_dup_profile(profile);
    + }
    + rcu_read_unlock();
    +
    + return profile;
    +}
    +
    +static inline struct aa_profile *aa_find_profile(const char *name)
    +{
    + struct aa_profile *profile = NULL;
    +
    + read_lock(&profile_list_lock);
    + profile = aa_dup_profile(__aa_find_profile(name, &profile_list));
    + read_unlock(&profile_list_lock);
    +
    + return profile;
    +}
    +
    +static inline struct aa_task_context *aa_alloc_task_context(gfp_t flags)
    +{
    + struct aa_task_context *cxt;
    +
    + cxt = kzalloc(sizeof(*cxt), flags);
    + if (cxt) {
    + INIT_LIST_HEAD(&cxt->list);
    + INIT_RCU_HEAD(&cxt->rcu);
    + }
    +
    + return cxt;
    +}
    +
    +static inline void aa_free_task_context(struct aa_task_context *cxt)
    +{
    + if (cxt) {
    + aa_put_profile(cxt->profile);
    + kfree(cxt);
    + }
    +}
    +
    +/**
    + * lock_profile - lock a profile
    + * @profile: the profile to lock
    + *
    + * While the profile is locked, local interrupts are disabled. This also
    + * gives us RCU reader safety.
    + */
    +static inline void lock_profile(struct aa_profile *profile)
    +{
    + /* We always lock top-level profiles instead of children. */
    + if (profile)
    + profile = profile->parent;
    +
    + /*
    + * Lock the profile.
    + *
    + * Need to disable interrupts here because this lock is used in
    + * the task_free_security hook, which may run in RCU context.
    + */
    + if (profile)
    + spin_lock_irqsave(&profile->lock, profile->int_flags);
    +}
    +
    +/**
    + * unlock_profile - unlock a profile
    + * @profile: the profile to unlock
    + */
    +static inline void unlock_profile(struct aa_profile *profile)
    +{
    + /* We always lock top-level profiles instead of children. */
    + if (profile)
    + profile = profile->parent;
    +
    + /* Unlock the profile. */
    + if (profile)
    + spin_unlock_irqrestore(&profile->lock, profile->int_flags);
    +}
    +
    +/**
    + * lock_both_profiles - lock two profiles in a deadlock-free way
    + * @profile1: profile to lock (may be NULL)
    + * @profile2: profile to lock (may be NULL)
    + *
    + * The order in which profiles are passed into lock_both_profiles() /
    + * unlock_both_profiles() does not matter.
    + * While the profile is locked, local interrupts are disabled. This also
    + * gives us RCU reader safety.
    + */
    +static inline void lock_both_profiles(struct aa_profile *profile1,
    + struct aa_profile *profile2)
    +{
    + /* We always lock top-level profiles instead of children. */
    + if (profile1)
    + profile1 = profile1->parent;
    + if (profile2)
    + profile2 = profile2->parent;
    +
    + /*
    + * Lock the two profiles.
    + *
    + * We need to disable interrupts because the profile locks are
    + * used in the task_free_security hook, which may run in RCU
    + * context.
    + *
    + * Do not nest spin_lock_irqsave()/spin_unlock_irqresore():
    + * interrupts only need to be turned off once.
    + */
    + if (!profile1 || profile1 == profile2) {
    + if (profile2)
    + spin_lock_irqsave(&profile2->lock, profile2->int_flags);
    + } else if (profile1 > profile2) {
    + /* profile1 cannot be NULL here. */
    + spin_lock_irqsave(&profile1->lock, profile1->int_flags);
    + if (profile2)
    + spin_lock(&profile2->lock);
    +
    + } else {
    + /* profile2 cannot be NULL here. */
    + spin_lock_irqsave(&profile2->lock, profile2->int_flags);
    + spin_lock(&profile1->lock);
    + }
    +}
    +
    +/**
    + * unlock_both_profiles - unlock two profiles in a deadlock-free way
    + * @profile1: profile to unlock (may be NULL)
    + * @profile2: profile to unlock (may be NULL)
    + *
    + * The order in which profiles are passed into lock_both_profiles() /
    + * unlock_both_profiles() does not matter.
    + * While the profile is locked, local interrupts are disabled. This also
    + * gives us RCU reader safety.
    + */
    +static inline void unlock_both_profiles(struct aa_profile *profile1,
    + struct aa_profile *profile2)
    +{
    + /* We always lock top-level profiles instead of children. */
    + if (profile1)
    + profile1 = profile1->parent;
    + if (profile2)
    + profile2 = profile2->parent;
    +
    + /* Unlock the two profiles. */
    + if (!profile1 || profile1 == profile2) {
    + if (profile2)
    + spin_unlock_irqrestore(&profile2->lock,
    + profile2->int_flags);
    + } else if (profile1 > profile2) {
    + /* profile1 cannot be NULL here. */
    + if (profile2)
    + spin_unlock(&profile2->lock);
    + spin_unlock_irqrestore(&profile1->lock, profile1->int_flags);
    + } else {
    + /* profile2 cannot be NULL here. */
    + spin_unlock(&profile1->lock);
    + spin_unlock_irqrestore(&profile2->lock, profile2->int_flags);
    + }
    +}
    +
    +static inline unsigned int aa_match(struct aa_dfa *dfa, const char *pathname)
    +{
    + return dfa ? aa_dfa_match(dfa, pathname) : 0;
    +}
    +
    +#endif /* __INLINE_H__ */
    --- /dev/null
    +++ b/security/apparmor/list.c
    @@ -0,0 +1,94 @@
    +/*
    + * Copyright (C) 1998-2007 Novell/SUSE
    + *
    + * 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, version 2 of the
    + * License.
    + *
    + * AppArmor Profile List Management
    + */
    +
    +#include <linux/seq_file.h>
    +#include "apparmor.h"
    +#include "inline.h"
    +
    +/* list of all profiles and lock */
    +LIST_HEAD(profile_list);
    +rwlock_t profile_list_lock = RW_LOCK_UNLOCKED;
    +
    +/**
    + * __aa_find_profile - look up a profile on the profile list
    + * @name: name of profile to find
    + * @head: list to search
    + *
    + * Returns a pointer to the profile on the list, or NULL if no profile
    + * called @name exists. The caller must hold the profile_list_lock.
    + */
    +struct aa_profile *__aa_find_profile(const char *name, struct list_head *head)
    +{
    + struct aa_profile *profile;
    +
    + list_for_each_entry(profile, head, list) {
    + if (!strcmp(profile->name, name))
    + return profile;
    + }
    +
    + return NULL;
    +}
    +
    +/**
    + * aa_profilelist_release - Remove all profiles from profile_list
    + */
    +void aa_profilelist_release(void)
    +{
    + struct aa_profile *p, *tmp;
    +
    + write_lock(&profile_list_lock);
    + list_for_each_entry_safe(p, tmp, &profile_list, list) {
    + list_del_init(&p->list);
    + aa_put_profile(p);
    + }
    + write_unlock(&profile_list_lock);
    +}
    +
    +static void *p_start(struct seq_file *f, loff_t *pos)
    +{
    + struct aa_profile *node;
    + loff_t l = *pos;
    +
    + read_lock(&profile_list_lock);
    + list_for_each_entry(node, &profile_list, list)
    + if (!l--)
    + return node;
    + return NULL;
    +}
    +
    +static void *p_next(struct seq_file *f, void *p, loff_t *pos)
    +{
    + struct list_head *lh = ((struct aa_profile *)p)->list.next;
    + (*pos)++;
    + return lh == &profile_list ?
    + NULL : list_entry(lh, struct aa_profile, list);
    +}
    +
    +static void p_stop(struct seq_file *f, void *v)
    +{
    + read_unlock(&profile_list_lock);
    +}
    +
    +static int seq_show_profile(struct seq_file *f, void *v)
    +{
    + struct aa_profile *profile = (struct aa_profile *)v;
    + seq_printf(f, "%s (%s)\n", profile->name,
    + PROFILE_COMPLAIN(profile) ? "complain" : "enforce");
    + return 0;
    +}
    +
    +/* Used in apparmorfs.c */
    +struct seq_operations apparmorfs_profiles_op = {
    + .start = p_start,
    + .next = p_next,
    + .stop = p_stop,
    + .show = seq_show_profile,
    +};
    --- /dev/null
    +++ b/security/apparmor/locking.txt
    @@ -0,0 +1,59 @@
    +Locking in AppArmor
    +===================
    +
    +Lock hierarchy:
    +
    + aa_interface_lock
    + profile_list_lock
    + aa_profile->lock
    + task_lock()
    +
    +
    +Which lock protects what?
    +
    + /-----------------------+-------------------------------\
    + | Variable | Lock |
    + >-----------------------+-------------------------------<
    + | profile_list | profile_list_lock |
    + +-----------------------+-------------------------------+
    + | aa_profile | (reference count) |
    + +-----------------------+-------------------------------+
    + | aa_profile-> | aa_profile->lock |
    + | isstale, | |
    + | task_contexts | |
    + +-----------------------+-------------------------------+
    + | task_struct->security | read: RCU |
    + | | write: task_lock() |
    + +-----------------------+-------------------------------+
    + | aa_profile->sub | handle on the profile (list |
    + | | is never modified) |
    + \-----------------------+-------------------------------/
    +
    +(Obviously, the list_heads embedded in data structures are always
    +protected with the lock that also protects the list.)
    +
    +When moving a task context from one profile to another, we grab both
    +profile locks with lock_both_profiles(). This ensures that both locks
    +are always taken in the same order, and so we won't deadlock.
    +
    +Since task_struct->security is RCU protected the aa_task_struct it
    +references is only guarenteed to exist for the rcu cycle. Where
    +aa_task_context->profile is needed in blocking operations the
    +profile's reference count is incremented and the profile reference
    +is used.
    +
    +Profiles on profile_list are never stale: when a profile becomes stale,
    +it is removed from profile_list at the same time (under profile_list_lock
    +and aa_profile->lock).
    +
    +The aa_interface_lock is taken whenever user-space modifies the profile
    +list, and can sleep. This ensures that profile loading/replacement/removal
    +won't race with itself. We release the profile_list_lock as soon as
    +possible to avoid stalling exec during profile loading/replacement/removal.
    +
    +lock_dep reports a false 'possible irq lock inversion dependency detected'
    +when the profile lock is taken in aa_release. This is due to that the
    +task_lock is often taken inside the profile lock but other kernel code
    +takes the task_lock with interrupts enabled. A deadlock will not actually
    +occur because apparmor does not take the task_lock in hard_irq or soft_irq
    +context.
    --- /dev/null
    +++ b/security/apparmor/procattr.c
    @@ -0,0 +1,138 @@
    +/*
    + * Copyright (C) 1998-2007 Novell/SUSE
    + *
    + * 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, version 2 of the
    + * License.
    + *
    + * AppArmor /proc/pid/attr handling
    + */
    +
    +#include "apparmor.h"
    +#include "inline.h"
    +
    +int aa_getprocattr(struct aa_profile *profile, char **string, unsigned *len)
    +{
    + char *str;
    +
    + if (profile) {
    + const char *mode_str = PROFILE_COMPLAIN(profile) ?
    + " (complain)" : " (enforce)";
    +
    + *len = ((profile != profile->parent) ?
    + strlen(profile->parent->name) + 1 : 0) +
    + strlen(mode_str) + strlen(profile->name) + 1;
    + str = kmalloc(*len, GFP_ATOMIC);
    + if (!str)
    + return -ENOMEM;
    +
    + if (profile != profile->parent) {
    + memcpy(str, profile->parent->name,
    + strlen(profile->parent->name));
    + str += strlen(profile->parent->name);
    + *str++ = '^';
    + }
    + memcpy(str, profile->name, strlen(profile->name));
    + str += strlen(profile->name);
    + memcpy(str, mode_str, strlen(mode_str));
    + str += strlen(mode_str);
    + *str++ = '\n';
    + str -= *len;
    + } else {
    + const char *unconfined_str = "unconfined\n";
    +
    + *len = strlen(unconfined_str);
    + str = kmalloc(*len, GFP_ATOMIC);
    + if (!str)
    + return -ENOMEM;
    +
    + memcpy(str, unconfined_str, *len);
    + }
    + *string = str;
    +
    + return 0;
    +}
    +
    +int aa_setprocattr_changehat(char *args)
    +{
    + char *hat;
    + u64 magic;
    +
    + magic = simple_strtoull(args, &hat, 16);
    + if (hat == args || *hat != '^') {
    + AA_ERROR("change_hat: Invalid input '%s'", args);
    + return -EINVAL;
    + }
    + hat++; /* skip ^ */
    + if (!*hat)
    + hat = NULL;
    + if (!hat && !magic) {
    + AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
    + return -EINVAL;
    + }
    +
    + AA_DEBUG("%s: Magic 0x%llx Hat '%s'\n",
    + __FUNCTION__, magic, hat ? hat : NULL);
    +
    + return aa_change_hat(hat, magic);
    +}
    +
    +int aa_setprocattr_setprofile(struct task_struct *task, char *args)
    +{
    + struct aa_profile *old_profile, *new_profile;
    +
    + AA_DEBUG("%s: current %d\n",
    + __FUNCTION__, current->pid);
    +
    +repeat:
    + if (strcmp(args, "unconfined") == 0)
    + new_profile = NULL;
    + else {
    + new_profile = aa_find_profile(args);
    + if (!new_profile) {
    + aa_audit_message(NULL, GFP_KERNEL, "Unable to switch "
    + "task %d to profile '%s'. No such "
    + "profile.",
    + task->pid, args);
    +
    + return -EINVAL;
    + }
    + }
    +
    + old_profile = __aa_replace_profile(task, new_profile, 0);
    + if (IS_ERR(old_profile)) {
    + int error;
    +
    + aa_put_profile(new_profile);
    + error = PTR_ERR(old_profile);
    + if (error == -ESTALE)
    + goto repeat;
    + return error;
    + }
    +
    + if (new_profile) {
    + aa_audit_message(NULL, GFP_KERNEL, "Switching task %d profile "
    + "%s active %s to new profile %s",
    + task->pid, old_profile ?
    + old_profile->parent->name : "unconfined",
    + old_profile ? old_profile->name : "unconfined",
    + args);
    + } else {
    + if (old_profile) {
    + aa_audit_message(NULL, GFP_KERNEL, "Unconfining task "
    + "%d profile %s active %s",
    + task->pid, old_profile->parent->name,
    + old_profile->name);
    + } else {
    + aa_audit_message(NULL, GFP_KERNEL, "task %d is already "
    + "unconfined",
    + task->pid);
    + }
    + }
    +
    + aa_put_profile(old_profile);
    + aa_put_profile(new_profile);
    +
    + return 0;
    +}
    --
    -
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