TOMOYO Linux Cross Reference
Linux/security/apparmor/apparmorfs.c

   // SPDX-License-Identifier: GPL-2.0-only
   /*
    * AppArmor security module
    *
    * This file contains AppArmor /sys/kernel/security/apparmor interface functions
    *
    * Copyright (C) 1998-2008 Novell/SUSE
    * Copyright 2009-2010 Canonical Ltd.
    */
  
  #include <linux/ctype.h>
  #include <linux/security.h>
  #include <linux/vmalloc.h>
  #include <linux/init.h>
  #include <linux/seq_file.h>
  #include <linux/uaccess.h>
  #include <linux/mount.h>
  #include <linux/namei.h>
  #include <linux/capability.h>
  #include <linux/rcupdate.h>
  #include <linux/fs.h>
  #include <linux/fs_context.h>
  #include <linux/poll.h>
  #include <linux/zstd.h>
  #include <uapi/linux/major.h>
  #include <uapi/linux/magic.h>
  
  #include "include/apparmor.h"
  #include "include/apparmorfs.h"
  #include "include/audit.h"
  #include "include/cred.h"
  #include "include/crypto.h"
  #include "include/ipc.h"
  #include "include/label.h"
  #include "include/policy.h"
  #include "include/policy_ns.h"
  #include "include/resource.h"
  #include "include/policy_unpack.h"
  #include "include/task.h"
  
  /*
   * The apparmor filesystem interface used for policy load and introspection
   * The interface is split into two main components based on their function
   * a securityfs component:
   *   used for static files that are always available, and which allows
   *   userspace to specificy the location of the security filesystem.
   *
   *   fns and data are prefixed with
   *      aa_sfs_
   *
   * an apparmorfs component:
   *   used loaded policy content and introspection. It is not part of  a
   *   regular mounted filesystem and is available only through the magic
   *   policy symlink in the root of the securityfs apparmor/ directory.
   *   Tasks queries will be magically redirected to the correct portion
   *   of the policy tree based on their confinement.
   *
   *   fns and data are prefixed with
   *      aafs_
   *
   * The aa_fs_ prefix is used to indicate the fn is used by both the
   * securityfs and apparmorfs filesystems.
   */
  
  
  /*
   * support fns
   */
  
  struct rawdata_f_data {
          struct aa_loaddata *loaddata;
  };
  
  #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
  #define RAWDATA_F_DATA_BUF(p) (char *)(p + 1)
  
  static void rawdata_f_data_free(struct rawdata_f_data *private)
  {
          if (!private)
                  return;
  
          aa_put_loaddata(private->loaddata);
          kvfree(private);
  }
  
  static struct rawdata_f_data *rawdata_f_data_alloc(size_t size)
  {
          struct rawdata_f_data *ret;
  
          if (size > SIZE_MAX - sizeof(*ret))
                  return ERR_PTR(-EINVAL);
  
          ret = kvzalloc(sizeof(*ret) + size, GFP_KERNEL);
          if (!ret)
                  return ERR_PTR(-ENOMEM);
  
          return ret;
  }
  #endif
 
 /**
  * mangle_name - mangle a profile name to std profile layout form
  * @name: profile name to mangle  (NOT NULL)
  * @target: buffer to store mangled name, same length as @name (MAYBE NULL)
  *
  * Returns: length of mangled name
  */
 static int mangle_name(const char *name, char *target)
 {
         char *t = target;
 
         while (*name == '/' || *name == '.')
                 name++;
 
         if (target) {
                 for (; *name; name++) {
                         if (*name == '/')
                                 *(t)++ = '.';
                         else if (isspace(*name))
                                 *(t)++ = '_';
                         else if (isalnum(*name) || strchr("._-", *name))
                                 *(t)++ = *name;
                 }
 
                 *t = 0;
         } else {
                 int len = 0;
                 for (; *name; name++) {
                         if (isalnum(*name) || isspace(*name) ||
                             strchr("/._-", *name))
                                 len++;
                 }
 
                 return len;
         }
 
         return t - target;
 }
 
 
 /*
  * aafs - core fns and data for the policy tree
  */
 
 #define AAFS_NAME               "apparmorfs"
 static struct vfsmount *aafs_mnt;
 static int aafs_count;
 
 
 static int aafs_show_path(struct seq_file *seq, struct dentry *dentry)
 {
         seq_printf(seq, "%s:[%lu]", AAFS_NAME, d_inode(dentry)->i_ino);
         return 0;
 }
 
 static void aafs_free_inode(struct inode *inode)
 {
         if (S_ISLNK(inode->i_mode))
                 kfree(inode->i_link);
         free_inode_nonrcu(inode);
 }
 
 static const struct super_operations aafs_super_ops = {
         .statfs = simple_statfs,
         .free_inode = aafs_free_inode,
         .show_path = aafs_show_path,
 };
 
 static int apparmorfs_fill_super(struct super_block *sb, struct fs_context *fc)
 {
         static struct tree_descr files[] = { {""} };
         int error;
 
         error = simple_fill_super(sb, AAFS_MAGIC, files);
         if (error)
                 return error;
         sb->s_op = &aafs_super_ops;
 
         return 0;
 }
 
 static int apparmorfs_get_tree(struct fs_context *fc)
 {
         return get_tree_single(fc, apparmorfs_fill_super);
 }
 
 static const struct fs_context_operations apparmorfs_context_ops = {
         .get_tree       = apparmorfs_get_tree,
 };
 
 static int apparmorfs_init_fs_context(struct fs_context *fc)
 {
         fc->ops = &apparmorfs_context_ops;
         return 0;
 }
 
 static struct file_system_type aafs_ops = {
         .owner = THIS_MODULE,
         .name = AAFS_NAME,
         .init_fs_context = apparmorfs_init_fs_context,
         .kill_sb = kill_anon_super,
 };
 
 /**
  * __aafs_setup_d_inode - basic inode setup for apparmorfs
  * @dir: parent directory for the dentry
  * @dentry: dentry we are seting the inode up for
  * @mode: permissions the file should have
  * @data: data to store on inode.i_private, available in open()
  * @link: if symlink, symlink target string
  * @fops: struct file_operations that should be used
  * @iops: struct of inode_operations that should be used
  */
 static int __aafs_setup_d_inode(struct inode *dir, struct dentry *dentry,
                                umode_t mode, void *data, char *link,
                                const struct file_operations *fops,
                                const struct inode_operations *iops)
 {
         struct inode *inode = new_inode(dir->i_sb);
 
         AA_BUG(!dir);
         AA_BUG(!dentry);
 
         if (!inode)
                 return -ENOMEM;
 
         inode->i_ino = get_next_ino();
         inode->i_mode = mode;
         simple_inode_init_ts(inode);
         inode->i_private = data;
         if (S_ISDIR(mode)) {
                 inode->i_op = iops ? iops : &simple_dir_inode_operations;
                 inode->i_fop = &simple_dir_operations;
                 inc_nlink(inode);
                 inc_nlink(dir);
         } else if (S_ISLNK(mode)) {
                 inode->i_op = iops ? iops : &simple_symlink_inode_operations;
                 inode->i_link = link;
         } else {
                 inode->i_fop = fops;
         }
         d_instantiate(dentry, inode);
         dget(dentry);
 
         return 0;
 }
 
 /**
  * aafs_create - create a dentry in the apparmorfs filesystem
  *
  * @name: name of dentry to create
  * @mode: permissions the file should have
  * @parent: parent directory for this dentry
  * @data: data to store on inode.i_private, available in open()
  * @link: if symlink, symlink target string
  * @fops: struct file_operations that should be used for
  * @iops: struct of inode_operations that should be used
  *
  * This is the basic "create a xxx" function for apparmorfs.
  *
  * Returns a pointer to a dentry if it succeeds, that must be free with
  * aafs_remove(). Will return ERR_PTR on failure.
  */
 static struct dentry *aafs_create(const char *name, umode_t mode,
                                   struct dentry *parent, void *data, void *link,
                                   const struct file_operations *fops,
                                   const struct inode_operations *iops)
 {
         struct dentry *dentry;
         struct inode *dir;
         int error;
 
         AA_BUG(!name);
         AA_BUG(!parent);
 
         if (!(mode & S_IFMT))
                 mode = (mode & S_IALLUGO) | S_IFREG;
 
         error = simple_pin_fs(&aafs_ops, &aafs_mnt, &aafs_count);
         if (error)
                 return ERR_PTR(error);
 
         dir = d_inode(parent);
 
         inode_lock(dir);
         dentry = lookup_one_len(name, parent, strlen(name));
         if (IS_ERR(dentry)) {
                 error = PTR_ERR(dentry);
                 goto fail_lock;
         }
 
         if (d_really_is_positive(dentry)) {
                 error = -EEXIST;
                 goto fail_dentry;
         }
 
         error = __aafs_setup_d_inode(dir, dentry, mode, data, link, fops, iops);
         if (error)
                 goto fail_dentry;
         inode_unlock(dir);
 
         return dentry;
 
 fail_dentry:
         dput(dentry);
 
 fail_lock:
         inode_unlock(dir);
         simple_release_fs(&aafs_mnt, &aafs_count);
 
         return ERR_PTR(error);
 }
 
 /**
  * aafs_create_file - create a file in the apparmorfs filesystem
  *
  * @name: name of dentry to create
  * @mode: permissions the file should have
  * @parent: parent directory for this dentry
  * @data: data to store on inode.i_private, available in open()
  * @fops: struct file_operations that should be used for
  *
  * see aafs_create
  */
 static struct dentry *aafs_create_file(const char *name, umode_t mode,
                                        struct dentry *parent, void *data,
                                        const struct file_operations *fops)
 {
         return aafs_create(name, mode, parent, data, NULL, fops, NULL);
 }
 
 /**
  * aafs_create_dir - create a directory in the apparmorfs filesystem
  *
  * @name: name of dentry to create
  * @parent: parent directory for this dentry
  *
  * see aafs_create
  */
 static struct dentry *aafs_create_dir(const char *name, struct dentry *parent)
 {
         return aafs_create(name, S_IFDIR | 0755, parent, NULL, NULL, NULL,
                            NULL);
 }
 
 /**
  * aafs_remove - removes a file or directory from the apparmorfs filesystem
  *
  * @dentry: dentry of the file/directory/symlink to removed.
  */
 static void aafs_remove(struct dentry *dentry)
 {
         struct inode *dir;
 
         if (!dentry || IS_ERR(dentry))
                 return;
 
         dir = d_inode(dentry->d_parent);
         inode_lock(dir);
         if (simple_positive(dentry)) {
                 if (d_is_dir(dentry))
                         simple_rmdir(dir, dentry);
                 else
                         simple_unlink(dir, dentry);
                 d_delete(dentry);
                 dput(dentry);
         }
         inode_unlock(dir);
         simple_release_fs(&aafs_mnt, &aafs_count);
 }
 
 
 /*
  * aa_fs - policy load/replace/remove
  */
 
 /**
  * aa_simple_write_to_buffer - common routine for getting policy from user
  * @userbuf: user buffer to copy data from  (NOT NULL)
  * @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
  * @copy_size: size of data to copy from user buffer
  * @pos: position write is at in the file (NOT NULL)
  *
  * Returns: kernel buffer containing copy of user buffer data or an
  *          ERR_PTR on failure.
  */
 static struct aa_loaddata *aa_simple_write_to_buffer(const char __user *userbuf,
                                                      size_t alloc_size,
                                                      size_t copy_size,
                                                      loff_t *pos)
 {
         struct aa_loaddata *data;
 
         AA_BUG(copy_size > alloc_size);
 
         if (*pos != 0)
                 /* only writes from pos 0, that is complete writes */
                 return ERR_PTR(-ESPIPE);
 
         /* freed by caller to simple_write_to_buffer */
         data = aa_loaddata_alloc(alloc_size);
         if (IS_ERR(data))
                 return data;
 
         data->size = copy_size;
         if (copy_from_user(data->data, userbuf, copy_size)) {
                 aa_put_loaddata(data);
                 return ERR_PTR(-EFAULT);
         }
 
         return data;
 }
 
 static ssize_t policy_update(u32 mask, const char __user *buf, size_t size,
                              loff_t *pos, struct aa_ns *ns)
 {
         struct aa_loaddata *data;
         struct aa_label *label;
         ssize_t error;
 
         label = begin_current_label_crit_section();
 
         /* high level check about policy management - fine grained in
          * below after unpack
          */
         error = aa_may_manage_policy(current_cred(), label, ns, mask);
         if (error)
                 goto end_section;
 
         data = aa_simple_write_to_buffer(buf, size, size, pos);
         error = PTR_ERR(data);
         if (!IS_ERR(data)) {
                 error = aa_replace_profiles(ns, label, mask, data);
                 aa_put_loaddata(data);
         }
 end_section:
         end_current_label_crit_section(label);
 
         return error;
 }
 
 /* .load file hook fn to load policy */
 static ssize_t profile_load(struct file *f, const char __user *buf, size_t size,
                             loff_t *pos)
 {
         struct aa_ns *ns = aa_get_ns(f->f_inode->i_private);
         int error = policy_update(AA_MAY_LOAD_POLICY, buf, size, pos, ns);
 
         aa_put_ns(ns);
 
         return error;
 }
 
 static const struct file_operations aa_fs_profile_load = {
         .write = profile_load,
         .llseek = default_llseek,
 };
 
 /* .replace file hook fn to load and/or replace policy */
 static ssize_t profile_replace(struct file *f, const char __user *buf,
                                size_t size, loff_t *pos)
 {
         struct aa_ns *ns = aa_get_ns(f->f_inode->i_private);
         int error = policy_update(AA_MAY_LOAD_POLICY | AA_MAY_REPLACE_POLICY,
                                   buf, size, pos, ns);
         aa_put_ns(ns);
 
         return error;
 }
 
 static const struct file_operations aa_fs_profile_replace = {
         .write = profile_replace,
         .llseek = default_llseek,
 };
 
 /* .remove file hook fn to remove loaded policy */
 static ssize_t profile_remove(struct file *f, const char __user *buf,
                               size_t size, loff_t *pos)
 {
         struct aa_loaddata *data;
         struct aa_label *label;
         ssize_t error;
         struct aa_ns *ns = aa_get_ns(f->f_inode->i_private);
 
         label = begin_current_label_crit_section();
         /* high level check about policy management - fine grained in
          * below after unpack
          */
         error = aa_may_manage_policy(current_cred(), label, ns,
                                      AA_MAY_REMOVE_POLICY);
         if (error)
                 goto out;
 
         /*
          * 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);
 
         error = PTR_ERR(data);
         if (!IS_ERR(data)) {
                 data->data[size] = 0;
                 error = aa_remove_profiles(ns, label, data->data, size);
                 aa_put_loaddata(data);
         }
  out:
         end_current_label_crit_section(label);
         aa_put_ns(ns);
         return error;
 }
 
 static const struct file_operations aa_fs_profile_remove = {
         .write = profile_remove,
         .llseek = default_llseek,
 };
 
 struct aa_revision {
         struct aa_ns *ns;
         long last_read;
 };
 
 /* revision file hook fn for policy loads */
 static int ns_revision_release(struct inode *inode, struct file *file)
 {
         struct aa_revision *rev = file->private_data;
 
         if (rev) {
                 aa_put_ns(rev->ns);
                 kfree(rev);
         }
 
         return 0;
 }
 
 static ssize_t ns_revision_read(struct file *file, char __user *buf,
                                 size_t size, loff_t *ppos)
 {
         struct aa_revision *rev = file->private_data;
         char buffer[32];
         long last_read;
         int avail;
 
         mutex_lock_nested(&rev->ns->lock, rev->ns->level);
         last_read = rev->last_read;
         if (last_read == rev->ns->revision) {
                 mutex_unlock(&rev->ns->lock);
                 if (file->f_flags & O_NONBLOCK)
                         return -EAGAIN;
                 if (wait_event_interruptible(rev->ns->wait,
                                              last_read !=
                                              READ_ONCE(rev->ns->revision)))
                         return -ERESTARTSYS;
                 mutex_lock_nested(&rev->ns->lock, rev->ns->level);
         }
 
         avail = sprintf(buffer, "%ld\n", rev->ns->revision);
         if (*ppos + size > avail) {
                 rev->last_read = rev->ns->revision;
                 *ppos = 0;
         }
         mutex_unlock(&rev->ns->lock);
 
         return simple_read_from_buffer(buf, size, ppos, buffer, avail);
 }
 
 static int ns_revision_open(struct inode *inode, struct file *file)
 {
         struct aa_revision *rev = kzalloc(sizeof(*rev), GFP_KERNEL);
 
         if (!rev)
                 return -ENOMEM;
 
         rev->ns = aa_get_ns(inode->i_private);
         if (!rev->ns)
                 rev->ns = aa_get_current_ns();
         file->private_data = rev;
 
         return 0;
 }
 
 static __poll_t ns_revision_poll(struct file *file, poll_table *pt)
 {
         struct aa_revision *rev = file->private_data;
         __poll_t mask = 0;
 
         if (rev) {
                 mutex_lock_nested(&rev->ns->lock, rev->ns->level);
                 poll_wait(file, &rev->ns->wait, pt);
                 if (rev->last_read < rev->ns->revision)
                         mask |= EPOLLIN | EPOLLRDNORM;
                 mutex_unlock(&rev->ns->lock);
         }
 
         return mask;
 }
 
 void __aa_bump_ns_revision(struct aa_ns *ns)
 {
         WRITE_ONCE(ns->revision, READ_ONCE(ns->revision) + 1);
         wake_up_interruptible(&ns->wait);
 }
 
 static const struct file_operations aa_fs_ns_revision_fops = {
         .owner          = THIS_MODULE,
         .open           = ns_revision_open,
         .poll           = ns_revision_poll,
         .read           = ns_revision_read,
         .llseek         = generic_file_llseek,
         .release        = ns_revision_release,
 };
 
 static void profile_query_cb(struct aa_profile *profile, struct aa_perms *perms,
                              const char *match_str, size_t match_len)
 {
         struct aa_ruleset *rules = list_first_entry(&profile->rules,
                                                     typeof(*rules), list);
         struct aa_perms tmp = { };
         aa_state_t state = DFA_NOMATCH;
 
         if (profile_unconfined(profile))
                 return;
         if (rules->file->dfa && *match_str == AA_CLASS_FILE) {
                 state = aa_dfa_match_len(rules->file->dfa,
                                          rules->file->start[AA_CLASS_FILE],
                                          match_str + 1, match_len - 1);
                 if (state) {
                         struct path_cond cond = { };
 
                         tmp = *(aa_lookup_fperms(rules->file, state, &cond));
                 }
         } else if (rules->policy->dfa) {
                 if (!RULE_MEDIATES(rules, *match_str))
                         return; /* no change to current perms */
                 state = aa_dfa_match_len(rules->policy->dfa,
                                          rules->policy->start[0],
                                          match_str, match_len);
                 if (state)
                         tmp = *aa_lookup_perms(rules->policy, state);
         }
         aa_apply_modes_to_perms(profile, &tmp);
         aa_perms_accum_raw(perms, &tmp);
 }
 
 
 /**
  * query_data - queries a policy and writes its data to buf
  * @buf: the resulting data is stored here (NOT NULL)
  * @buf_len: size of buf
  * @query: query string used to retrieve data
  * @query_len: size of query including second NUL byte
  *
  * The buffers pointed to by buf and query may overlap. The query buffer is
  * parsed before buf is written to.
  *
  * The query should look like "<LABEL>\0<KEY>\0", where <LABEL> is the name of
  * the security confinement context and <KEY> is the name of the data to
  * retrieve. <LABEL> and <KEY> must not be NUL-terminated.
  *
  * Don't expect the contents of buf to be preserved on failure.
  *
  * Returns: number of characters written to buf or -errno on failure
  */
 static ssize_t query_data(char *buf, size_t buf_len,
                           char *query, size_t query_len)
 {
         char *out;
         const char *key;
         struct label_it i;
         struct aa_label *label, *curr;
         struct aa_profile *profile;
         struct aa_data *data;
         u32 bytes, blocks;
         __le32 outle32;
 
         if (!query_len)
                 return -EINVAL; /* need a query */
 
         key = query + strnlen(query, query_len) + 1;
         if (key + 1 >= query + query_len)
                 return -EINVAL; /* not enough space for a non-empty key */
         if (key + strnlen(key, query + query_len - key) >= query + query_len)
                 return -EINVAL; /* must end with NUL */
 
         if (buf_len < sizeof(bytes) + sizeof(blocks))
                 return -EINVAL; /* not enough space */
 
         curr = begin_current_label_crit_section();
         label = aa_label_parse(curr, query, GFP_KERNEL, false, false);
         end_current_label_crit_section(curr);
         if (IS_ERR(label))
                 return PTR_ERR(label);
 
         /* We are going to leave space for two numbers. The first is the total
          * number of bytes we are writing after the first number. This is so
          * users can read the full output without reallocation.
          *
          * The second number is the number of data blocks we're writing. An
          * application might be confined by multiple policies having data in
          * the same key.
          */
         memset(buf, 0, sizeof(bytes) + sizeof(blocks));
         out = buf + sizeof(bytes) + sizeof(blocks);
 
         blocks = 0;
         label_for_each_confined(i, label, profile) {
                 if (!profile->data)
                         continue;
 
                 data = rhashtable_lookup_fast(profile->data, &key,
                                               profile->data->p);
 
                 if (data) {
                         if (out + sizeof(outle32) + data->size > buf +
                             buf_len) {
                                 aa_put_label(label);
                                 return -EINVAL; /* not enough space */
                         }
                         outle32 = __cpu_to_le32(data->size);
                         memcpy(out, &outle32, sizeof(outle32));
                         out += sizeof(outle32);
                         memcpy(out, data->data, data->size);
                         out += data->size;
                         blocks++;
                 }
         }
         aa_put_label(label);
 
         outle32 = __cpu_to_le32(out - buf - sizeof(bytes));
         memcpy(buf, &outle32, sizeof(outle32));
         outle32 = __cpu_to_le32(blocks);
         memcpy(buf + sizeof(bytes), &outle32, sizeof(outle32));
 
         return out - buf;
 }
 
 /**
  * query_label - queries a label and writes permissions to buf
  * @buf: the resulting permissions string is stored here (NOT NULL)
  * @buf_len: size of buf
  * @query: binary query string to match against the dfa
  * @query_len: size of query
  * @view_only: only compute for querier's view
  *
  * The buffers pointed to by buf and query may overlap. The query buffer is
  * parsed before buf is written to.
  *
  * The query should look like "LABEL_NAME\0DFA_STRING" where LABEL_NAME is
  * the name of the label, in the current namespace, that is to be queried and
  * DFA_STRING is a binary string to match against the label(s)'s DFA.
  *
  * LABEL_NAME must be NUL terminated. DFA_STRING may contain NUL characters
  * but must *not* be NUL terminated.
  *
  * Returns: number of characters written to buf or -errno on failure
  */
 static ssize_t query_label(char *buf, size_t buf_len,
                            char *query, size_t query_len, bool view_only)
 {
         struct aa_profile *profile;
         struct aa_label *label, *curr;
         char *label_name, *match_str;
         size_t label_name_len, match_len;
         struct aa_perms perms;
         struct label_it i;
 
         if (!query_len)
                 return -EINVAL;
 
         label_name = query;
         label_name_len = strnlen(query, query_len);
         if (!label_name_len || label_name_len == query_len)
                 return -EINVAL;
 
         /**
          * The extra byte is to account for the null byte between the
          * profile name and dfa string. profile_name_len is greater
          * than zero and less than query_len, so a byte can be safely
          * added or subtracted.
          */
         match_str = label_name + label_name_len + 1;
         match_len = query_len - label_name_len - 1;
 
         curr = begin_current_label_crit_section();
         label = aa_label_parse(curr, label_name, GFP_KERNEL, false, false);
         end_current_label_crit_section(curr);
         if (IS_ERR(label))
                 return PTR_ERR(label);
 
         perms = allperms;
         if (view_only) {
                 label_for_each_in_ns(i, labels_ns(label), label, profile) {
                         profile_query_cb(profile, &perms, match_str, match_len);
                 }
         } else {
                 label_for_each(i, label, profile) {
                         profile_query_cb(profile, &perms, match_str, match_len);
                 }
         }
         aa_put_label(label);
 
         return scnprintf(buf, buf_len,
                       "allow 0x%08x\ndeny 0x%08x\naudit 0x%08x\nquiet 0x%08x\n",
                       perms.allow, perms.deny, perms.audit, perms.quiet);
 }
 
 /*
  * Transaction based IO.
  * The file expects a write which triggers the transaction, and then
  * possibly a read(s) which collects the result - which is stored in a
  * file-local buffer. Once a new write is performed, a new set of results
  * are stored in the file-local buffer.
  */
 struct multi_transaction {
         struct kref count;
         ssize_t size;
         char data[];
 };
 
 #define MULTI_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct multi_transaction))
 
 static void multi_transaction_kref(struct kref *kref)
 {
         struct multi_transaction *t;
 
         t = container_of(kref, struct multi_transaction, count);
         free_page((unsigned long) t);
 }
 
 static struct multi_transaction *
 get_multi_transaction(struct multi_transaction *t)
 {
         if  (t)
                 kref_get(&(t->count));
 
         return t;
 }
 
 static void put_multi_transaction(struct multi_transaction *t)
 {
         if (t)
                 kref_put(&(t->count), multi_transaction_kref);
 }
 
 /* does not increment @new's count */
 static void multi_transaction_set(struct file *file,
                                   struct multi_transaction *new, size_t n)
 {
         struct multi_transaction *old;
 
         AA_BUG(n > MULTI_TRANSACTION_LIMIT);
 
         new->size = n;
         spin_lock(&file->f_lock);
         old = (struct multi_transaction *) file->private_data;
         file->private_data = new;
         spin_unlock(&file->f_lock);
         put_multi_transaction(old);
 }
 
 static struct multi_transaction *multi_transaction_new(struct file *file,
                                                        const char __user *buf,
                                                        size_t size)
 {
         struct multi_transaction *t;
 
         if (size > MULTI_TRANSACTION_LIMIT - 1)
                 return ERR_PTR(-EFBIG);
 
         t = (struct multi_transaction *)get_zeroed_page(GFP_KERNEL);
         if (!t)
                 return ERR_PTR(-ENOMEM);
         kref_init(&t->count);
         if (copy_from_user(t->data, buf, size)) {
                 put_multi_transaction(t);
                 return ERR_PTR(-EFAULT);
         }
 
         return t;
 }
 
 static ssize_t multi_transaction_read(struct file *file, char __user *buf,
                                        size_t size, loff_t *pos)
 {
         struct multi_transaction *t;
         ssize_t ret;
 
         spin_lock(&file->f_lock);
         t = get_multi_transaction(file->private_data);
         spin_unlock(&file->f_lock);
 
         if (!t)
                 return 0;
 
         ret = simple_read_from_buffer(buf, size, pos, t->data, t->size);
         put_multi_transaction(t);
 
         return ret;
 }
 
 static int multi_transaction_release(struct inode *inode, struct file *file)
 {
         put_multi_transaction(file->private_data);
 
         return 0;
 }
 
 #define QUERY_CMD_LABEL         "label\0"
 #define QUERY_CMD_LABEL_LEN     6
 #define QUERY_CMD_PROFILE       "profile\0"
 #define QUERY_CMD_PROFILE_LEN   8
 #define QUERY_CMD_LABELALL      "labelall\0"
 #define QUERY_CMD_LABELALL_LEN  9
 #define QUERY_CMD_DATA          "data\0"
 #define QUERY_CMD_DATA_LEN      5
 
 /**
  * aa_write_access - generic permissions and data query
  * @file: pointer to open apparmorfs/access file
  * @ubuf: user buffer containing the complete query string (NOT NULL)
  * @count: size of ubuf
  * @ppos: position in the file (MUST BE ZERO)
  *
  * Allows for one permissions or data query per open(), write(), and read()
  * sequence. The only queries currently supported are label-based queries for
  * permissions or data.
  *
  * For permissions queries, ubuf must begin with "label\0", followed by the
  * profile query specific format described in the query_label() function
  * documentation.
  *
  * For data queries, ubuf must have the form "data\0<LABEL>\0<KEY>\0", where
  * <LABEL> is the name of the security confinement context and <KEY> is the
  * name of the data to retrieve.
  *
  * Returns: number of bytes written or -errno on failure
  */
 static ssize_t aa_write_access(struct file *file, const char __user *ubuf,
                                size_t count, loff_t *ppos)
 {
         struct multi_transaction *t;
         ssize_t len;
 
         if (*ppos)
                 return -ESPIPE;
 
         t = multi_transaction_new(file, ubuf, count);
         if (IS_ERR(t))
                 return PTR_ERR(t);
 
         if (count > QUERY_CMD_PROFILE_LEN &&
             !memcmp(t->data, QUERY_CMD_PROFILE, QUERY_CMD_PROFILE_LEN)) {
                 len = query_label(t->data, MULTI_TRANSACTION_LIMIT,
                                   t->data + QUERY_CMD_PROFILE_LEN,
                                   count - QUERY_CMD_PROFILE_LEN, true);
         } else if (count > QUERY_CMD_LABEL_LEN &&
                    !memcmp(t->data, QUERY_CMD_LABEL, QUERY_CMD_LABEL_LEN)) {
                 len = query_label(t->data, MULTI_TRANSACTION_LIMIT,
                                   t->data + QUERY_CMD_LABEL_LEN,
                                   count - QUERY_CMD_LABEL_LEN, true);
         } else if (count > QUERY_CMD_LABELALL_LEN &&
                    !memcmp(t->data, QUERY_CMD_LABELALL,
                            QUERY_CMD_LABELALL_LEN)) {
                 len = query_label(t->data, MULTI_TRANSACTION_LIMIT,
                                   t->data + QUERY_CMD_LABELALL_LEN,
                                   count - QUERY_CMD_LABELALL_LEN, false);
         } else if (count > QUERY_CMD_DATA_LEN &&
                    !memcmp(t->data, QUERY_CMD_DATA, QUERY_CMD_DATA_LEN)) {
                 len = query_data(t->data, MULTI_TRANSACTION_LIMIT,
                                  t->data + QUERY_CMD_DATA_LEN,
                                  count - QUERY_CMD_DATA_LEN);
         } else
                 len = -EINVAL;
 
         if (len < 0) {
                 put_multi_transaction(t);
                 return len;
         }
 
         multi_transaction_set(file, t, len);
 
         return count;
 }
 
 static const struct file_operations aa_sfs_access = {
         .write          = aa_write_access,
         .read           = multi_transaction_read,
         .release        = multi_transaction_release,
         .llseek         = generic_file_llseek,
 };
 
 static int aa_sfs_seq_show(struct seq_file *seq, void *v)
 {
         struct aa_sfs_entry *fs_file = seq->private;
 
         if (!fs_file)
                 return 0;
 
         switch (fs_file->v_type) {
         case AA_SFS_TYPE_BOOLEAN:
                 seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
                 break;
         case AA_SFS_TYPE_STRING:
                 seq_printf(seq, "%s\n", fs_file->v.string);
                 break;
         case AA_SFS_TYPE_U64:
                 seq_printf(seq, "%#08lx\n", fs_file->v.u64);
                 break;
         default:
                 /* Ignore unpritable entry types. */
                 break;
         }
 
         return 0;
 }
 
 static int aa_sfs_seq_open(struct inode *inode, struct file *file)
 {
         return single_open(file, aa_sfs_seq_show, inode->i_private);
 }
 
 const struct file_operations aa_sfs_seq_file_ops = {
         .owner          = THIS_MODULE,
         .open           = aa_sfs_seq_open,
         .read           = seq_read,
         .llseek         = seq_lseek,
         .release        = single_release,
 };
 
 /*
  * profile based file operations
  *     policy/profiles/XXXX/profiles/ *
  */
 
 #define SEQ_PROFILE_FOPS(NAME)                                                \
 static int seq_profile_ ##NAME ##_open(struct inode *inode, struct file *file)\
 {                                                                             \
         return seq_profile_open(inode, file, seq_profile_ ##NAME ##_show);    \
 }                                                                             \
                                                                               \
 static const struct file_operations seq_profile_ ##NAME ##_fops = {           \
         .owner          = THIS_MODULE,                                        \
         .open           = seq_profile_ ##NAME ##_open,                        \
         .read           = seq_read,                                           \
         .llseek         = seq_lseek,                                          \
         .release        = seq_profile_release,                                \
 }                                                                             \
 
 static int seq_profile_open(struct inode *inode, struct file *file,
                             int (*show)(struct seq_file *, void *))
 {
         struct aa_proxy *proxy = aa_get_proxy(inode->i_private);
         int error = single_open(file, show, proxy);
 
         if (error) {
                 file->private_data = NULL;
                 aa_put_proxy(proxy);
         }
 
         return error;
 }
 
 static int seq_profile_release(struct inode *inode, struct file *file)
 {
         struct seq_file *seq = (struct seq_file *) file->private_data;
         if (seq)
                 aa_put_proxy(seq->private);
         return single_release(inode, file);
 }
 
 static int seq_profile_name_show(struct seq_file *seq, void *v)
 {
         struct aa_proxy *proxy = seq->private;
         struct aa_label *label = aa_get_label_rcu(&proxy->label);
         struct aa_profile *profile = labels_profile(label);
         seq_printf(seq, "%s\n", profile->base.name);
         aa_put_label(label);
 
         return 0;
 }
 
 static int seq_profile_mode_show(struct seq_file *seq, void *v)
 {
         struct aa_proxy *proxy = seq->private;
         struct aa_label *label = aa_get_label_rcu(&proxy->label);
         struct aa_profile *profile = labels_profile(label);
         seq_printf(seq, "%s\n", aa_profile_mode_names[profile->mode]);
         aa_put_label(label);
 
         return 0;
 }
 
 static int seq_profile_attach_show(struct seq_file *seq, void *v)
 {
         struct aa_proxy *proxy = seq->private;
         struct aa_label *label = aa_get_label_rcu(&proxy->label);
         struct aa_profile *profile = labels_profile(label);
         if (profile->attach.xmatch_str)
                 seq_printf(seq, "%s\n", profile->attach.xmatch_str);
         else if (profile->attach.xmatch->dfa)
                 seq_puts(seq, "<unknown>\n");
         else
                 seq_printf(seq, "%s\n", profile->base.name);
         aa_put_label(label);
 
         return 0;
 }
 
 static int seq_profile_hash_show(struct seq_file *seq, void *v)
 {
         struct aa_proxy *proxy = seq->private;
         struct aa_label *label = aa_get_label_rcu(&proxy->label);
         struct aa_profile *profile = labels_profile(label);
         unsigned int i, size = aa_hash_size();
 
         if (profile->hash) {
                 for (i = 0; i < size; i++)
                         seq_printf(seq, "%.2x", profile->hash[i]);
                 seq_putc(seq, '\n');
         }
         aa_put_label(label);
 
         return 0;
 }
 
 SEQ_PROFILE_FOPS(name);
 SEQ_PROFILE_FOPS(mode);
 SEQ_PROFILE_FOPS(attach);
 SEQ_PROFILE_FOPS(hash);
 
 /*
  * namespace based files
  *     several root files and
  *     policy/ *
  */
 
 #define SEQ_NS_FOPS(NAME)                                                     \
 static int seq_ns_ ##NAME ##_open(struct inode *inode, struct file *file)     \
 {                                                                             \
         return single_open(file, seq_ns_ ##NAME ##_show, inode->i_private);   \
 }                                                                             \
                                                                               \
 static const struct file_operations seq_ns_ ##NAME ##_fops = {        \
         .owner          = THIS_MODULE,                                        \
         .open           = seq_ns_ ##NAME ##_open,                             \
         .read           = seq_read,                                           \
         .llseek         = seq_lseek,                                          \
         .release        = single_release,                                     \
 }                                                                             \
 
 static int seq_ns_stacked_show(struct seq_file *seq, void *v)
 {
         struct aa_label *label;
 
         label = begin_current_label_crit_section();
         seq_printf(seq, "%s\n", label->size > 1 ? "yes" : "no");
         end_current_label_crit_section(label);
 
         return 0;
 }
 
 static int seq_ns_nsstacked_show(struct seq_file *seq, void *v)
 {
         struct aa_label *label;
         struct aa_profile *profile;
         struct label_it it;
         int count = 1;
 
         label = begin_current_label_crit_section();
 
         if (label->size > 1) {
                 label_for_each(it, label, profile)
                         if (profile->ns != labels_ns(label)) {
                                 count++;
                                 break;
                         }
         }
 
         seq_printf(seq, "%s\n", count > 1 ? "yes" : "no");
         end_current_label_crit_section(label);
 
         return 0;
 }
 
 static int seq_ns_level_show(struct seq_file *seq, void *v)
 {
         struct aa_label *label;
 
         label = begin_current_label_crit_section();
         seq_printf(seq, "%d\n", labels_ns(label)->level);
         end_current_label_crit_section(label);
 
         return 0;
 }
 
 static int seq_ns_name_show(struct seq_file *seq, void *v)
 {
         struct aa_label *label = begin_current_label_crit_section();
         seq_printf(seq, "%s\n", labels_ns(label)->base.name);
         end_current_label_crit_section(label);
 
         return 0;
 }
 
 static int seq_ns_compress_min_show(struct seq_file *seq, void *v)
 {
         seq_printf(seq, "%d\n", AA_MIN_CLEVEL);
         return 0;
 }
 
 static int seq_ns_compress_max_show(struct seq_file *seq, void *v)
 {
         seq_printf(seq, "%d\n", AA_MAX_CLEVEL);
         return 0;
 }
 
 SEQ_NS_FOPS(stacked);
 SEQ_NS_FOPS(nsstacked);
 SEQ_NS_FOPS(level);
 SEQ_NS_FOPS(name);
 SEQ_NS_FOPS(compress_min);
 SEQ_NS_FOPS(compress_max);
 
 
 /* policy/raw_data/ * file ops */
 #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
 #define SEQ_RAWDATA_FOPS(NAME)                                                \
 static int seq_rawdata_ ##NAME ##_open(struct inode *inode, struct file *file)\
 {                                                                             \
         return seq_rawdata_open(inode, file, seq_rawdata_ ##NAME ##_show);    \
 }                                                                             \
                                                                               \
 static const struct file_operations seq_rawdata_ ##NAME ##_fops = {           \
         .owner          = THIS_MODULE,                                        \
         .open           = seq_rawdata_ ##NAME ##_open,                        \
         .read           = seq_read,                                           \
         .llseek         = seq_lseek,                                          \
         .release        = seq_rawdata_release,                                \
 }                                                                             \
 
 static int seq_rawdata_open(struct inode *inode, struct file *file,
                             int (*show)(struct seq_file *, void *))
 {
         struct aa_loaddata *data = __aa_get_loaddata(inode->i_private);
         int error;
 
         if (!data)
                 /* lost race this ent is being reaped */
                 return -ENOENT;
 
         error = single_open(file, show, data);
         if (error) {
                 AA_BUG(file->private_data &&
                        ((struct seq_file *)file->private_data)->private);
                 aa_put_loaddata(data);
         }
 
         return error;
 }
 
 static int seq_rawdata_release(struct inode *inode, struct file *file)
 {
         struct seq_file *seq = (struct seq_file *) file->private_data;
 
         if (seq)
                 aa_put_loaddata(seq->private);
 
         return single_release(inode, file);
 }
 
 static int seq_rawdata_abi_show(struct seq_file *seq, void *v)
 {
         struct aa_loaddata *data = seq->private;
 
         seq_printf(seq, "v%d\n", data->abi);
 
         return 0;
 }
 
 static int seq_rawdata_revision_show(struct seq_file *seq, void *v)
 {
         struct aa_loaddata *data = seq->private;
 
         seq_printf(seq, "%ld\n", data->revision);
 
         return 0;
 }
 
 static int seq_rawdata_hash_show(struct seq_file *seq, void *v)
 {
         struct aa_loaddata *data = seq->private;
         unsigned int i, size = aa_hash_size();
 
         if (data->hash) {
                 for (i = 0; i < size; i++)
                         seq_printf(seq, "%.2x", data->hash[i]);
                 seq_putc(seq, '\n');
         }
 
         return 0;
 }
 
 static int seq_rawdata_compressed_size_show(struct seq_file *seq, void *v)
 {
         struct aa_loaddata *data = seq->private;
 
         seq_printf(seq, "%zu\n", data->compressed_size);
 
         return 0;
 }
 
 SEQ_RAWDATA_FOPS(abi);
 SEQ_RAWDATA_FOPS(revision);
 SEQ_RAWDATA_FOPS(hash);
 SEQ_RAWDATA_FOPS(compressed_size);
 
 static int decompress_zstd(char *src, size_t slen, char *dst, size_t dlen)
 {
         if (slen < dlen) {
                 const size_t wksp_len = zstd_dctx_workspace_bound();
                 zstd_dctx *ctx;
                 void *wksp;
                 size_t out_len;
                 int ret = 0;
 
                 wksp = kvzalloc(wksp_len, GFP_KERNEL);
                 if (!wksp) {
                         ret = -ENOMEM;
                         goto cleanup;
                 }
                 ctx = zstd_init_dctx(wksp, wksp_len);
                 if (ctx == NULL) {
                         ret = -ENOMEM;
                         goto cleanup;
                 }
                 out_len = zstd_decompress_dctx(ctx, dst, dlen, src, slen);
                 if (zstd_is_error(out_len)) {
                         ret = -EINVAL;
                         goto cleanup;
                 }
 cleanup:
                 kvfree(wksp);
                 return ret;
         }
 
         if (dlen < slen)
                 return -EINVAL;
         memcpy(dst, src, slen);
         return 0;
 }
 
 static ssize_t rawdata_read(struct file *file, char __user *buf, size_t size,
                             loff_t *ppos)
 {
         struct rawdata_f_data *private = file->private_data;
 
         return simple_read_from_buffer(buf, size, ppos,
                                        RAWDATA_F_DATA_BUF(private),
                                        private->loaddata->size);
 }
 
 static int rawdata_release(struct inode *inode, struct file *file)
 {
         rawdata_f_data_free(file->private_data);
 
         return 0;
 }
 
 static int rawdata_open(struct inode *inode, struct file *file)
 {
         int error;
         struct aa_loaddata *loaddata;
         struct rawdata_f_data *private;
 
         if (!aa_current_policy_view_capable(NULL))
                 return -EACCES;
 
         loaddata = __aa_get_loaddata(inode->i_private);
         if (!loaddata)
                 /* lost race: this entry is being reaped */
                 return -ENOENT;
 
         private = rawdata_f_data_alloc(loaddata->size);
         if (IS_ERR(private)) {
                 error = PTR_ERR(private);
                 goto fail_private_alloc;
         }
 
         private->loaddata = loaddata;
 
         error = decompress_zstd(loaddata->data, loaddata->compressed_size,
                                 RAWDATA_F_DATA_BUF(private),
                                 loaddata->size);
         if (error)
                 goto fail_decompress;
 
         file->private_data = private;
         return 0;
 
 fail_decompress:
         rawdata_f_data_free(private);
         return error;
 
 fail_private_alloc:
         aa_put_loaddata(loaddata);
         return error;
 }
 
 static const struct file_operations rawdata_fops = {
         .open = rawdata_open,
         .read = rawdata_read,
         .llseek = generic_file_llseek,
         .release = rawdata_release,
 };
 
 static void remove_rawdata_dents(struct aa_loaddata *rawdata)
 {
         int i;
 
         for (i = 0; i < AAFS_LOADDATA_NDENTS; i++) {
                 if (!IS_ERR_OR_NULL(rawdata->dents[i])) {
                         /* no refcounts on i_private */
                         aafs_remove(rawdata->dents[i]);
                         rawdata->dents[i] = NULL;
                 }
         }
 }
 
 void __aa_fs_remove_rawdata(struct aa_loaddata *rawdata)
 {
         AA_BUG(rawdata->ns && !mutex_is_locked(&rawdata->ns->lock));
 
         if (rawdata->ns) {
                 remove_rawdata_dents(rawdata);
                 list_del_init(&rawdata->list);
                 aa_put_ns(rawdata->ns);
                 rawdata->ns = NULL;
         }
 }
 
 int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata)
 {
         struct dentry *dent, *dir;
 
         AA_BUG(!ns);
         AA_BUG(!rawdata);
         AA_BUG(!mutex_is_locked(&ns->lock));
         AA_BUG(!ns_subdata_dir(ns));
 
         /*
          * just use ns revision dir was originally created at. This is
          * under ns->lock and if load is successful revision will be
          * bumped and is guaranteed to be unique
          */
         rawdata->name = kasprintf(GFP_KERNEL, "%ld", ns->revision);
         if (!rawdata->name)
                 return -ENOMEM;
 
         dir = aafs_create_dir(rawdata->name, ns_subdata_dir(ns));
         if (IS_ERR(dir))
                 /* ->name freed when rawdata freed */
                 return PTR_ERR(dir);
         rawdata->dents[AAFS_LOADDATA_DIR] = dir;
 
         dent = aafs_create_file("abi", S_IFREG | 0444, dir, rawdata,
                                       &seq_rawdata_abi_fops);
         if (IS_ERR(dent))
                 goto fail;
         rawdata->dents[AAFS_LOADDATA_ABI] = dent;
 
         dent = aafs_create_file("revision", S_IFREG | 0444, dir, rawdata,
                                       &seq_rawdata_revision_fops);
         if (IS_ERR(dent))
                 goto fail;
         rawdata->dents[AAFS_LOADDATA_REVISION] = dent;
 
         if (aa_g_hash_policy) {
                 dent = aafs_create_file("sha256", S_IFREG | 0444, dir,
                                               rawdata, &seq_rawdata_hash_fops);
                 if (IS_ERR(dent))
                         goto fail;
                 rawdata->dents[AAFS_LOADDATA_HASH] = dent;
         }
 
         dent = aafs_create_file("compressed_size", S_IFREG | 0444, dir,
                                 rawdata,
                                 &seq_rawdata_compressed_size_fops);
         if (IS_ERR(dent))
                 goto fail;
         rawdata->dents[AAFS_LOADDATA_COMPRESSED_SIZE] = dent;
 
         dent = aafs_create_file("raw_data", S_IFREG | 0444,
                                       dir, rawdata, &rawdata_fops);
         if (IS_ERR(dent))
                 goto fail;
         rawdata->dents[AAFS_LOADDATA_DATA] = dent;
         d_inode(dent)->i_size = rawdata->size;
 
         rawdata->ns = aa_get_ns(ns);
         list_add(&rawdata->list, &ns->rawdata_list);
         /* no refcount on inode rawdata */
 
         return 0;
 
 fail:
         remove_rawdata_dents(rawdata);
 
         return PTR_ERR(dent);
 }
 #endif /* CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */
 
 
 /** fns to setup dynamic per profile/namespace files **/
 
 /*
  *
  * Requires: @profile->ns->lock held
  */
 void __aafs_profile_rmdir(struct aa_profile *profile)
 {
         struct aa_profile *child;
         int i;
 
         if (!profile)
                 return;
 
         list_for_each_entry(child, &profile->base.profiles, base.list)
                 __aafs_profile_rmdir(child);
 
         for (i = AAFS_PROF_SIZEOF - 1; i >= 0; --i) {
                 struct aa_proxy *proxy;
                 if (!profile->dents[i])
                         continue;
 
                 proxy = d_inode(profile->dents[i])->i_private;
                 aafs_remove(profile->dents[i]);
                 aa_put_proxy(proxy);
                 profile->dents[i] = NULL;
         }
 }
 
 /*
  *
  * Requires: @old->ns->lock held
  */
 void __aafs_profile_migrate_dents(struct aa_profile *old,
                                   struct aa_profile *new)
 {
         int i;
 
         AA_BUG(!old);
         AA_BUG(!new);
         AA_BUG(!mutex_is_locked(&profiles_ns(old)->lock));
 
         for (i = 0; i < AAFS_PROF_SIZEOF; i++) {
                 new->dents[i] = old->dents[i];
                 if (new->dents[i]) {
                         struct inode *inode = d_inode(new->dents[i]);
 
                         inode_set_mtime_to_ts(inode,
                                               inode_set_ctime_current(inode));
                 }
                 old->dents[i] = NULL;
         }
 }
 
 static struct dentry *create_profile_file(struct dentry *dir, const char *name,
                                           struct aa_profile *profile,
                                           const struct file_operations *fops)
 {
         struct aa_proxy *proxy = aa_get_proxy(profile->label.proxy);
         struct dentry *dent;
 
         dent = aafs_create_file(name, S_IFREG | 0444, dir, proxy, fops);
         if (IS_ERR(dent))
                 aa_put_proxy(proxy);
 
         return dent;
 }
 
 #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
 static int profile_depth(struct aa_profile *profile)
 {
         int depth = 0;
 
         rcu_read_lock();
         for (depth = 0; profile; profile = rcu_access_pointer(profile->parent))
                 depth++;
         rcu_read_unlock();
 
         return depth;
 }
 
 static char *gen_symlink_name(int depth, const char *dirname, const char *fname)
 {
         char *buffer, *s;
         int error;
         int size = depth * 6 + strlen(dirname) + strlen(fname) + 11;
 
         s = buffer = kmalloc(size, GFP_KERNEL);
         if (!buffer)
                 return ERR_PTR(-ENOMEM);
 
         for (; depth > 0; depth--) {
                 strcpy(s, "../../");
                 s += 6;
                 size -= 6;
         }
 
         error = snprintf(s, size, "raw_data/%s/%s", dirname, fname);
         if (error >= size || error < 0) {
                 kfree(buffer);
                 return ERR_PTR(-ENAMETOOLONG);
         }
 
         return buffer;
 }
 
 static const char *rawdata_get_link_base(struct dentry *dentry,
                                          struct inode *inode,
                                          struct delayed_call *done,
                                          const char *name)
 {
         struct aa_proxy *proxy = inode->i_private;
         struct aa_label *label;
         struct aa_profile *profile;
         char *target;
         int depth;
 
         if (!dentry)
                 return ERR_PTR(-ECHILD);
 
         label = aa_get_label_rcu(&proxy->label);
         profile = labels_profile(label);
         depth = profile_depth(profile);
         target = gen_symlink_name(depth, profile->rawdata->name, name);
         aa_put_label(label);
 
         if (IS_ERR(target))
                 return target;
 
         set_delayed_call(done, kfree_link, target);
 
         return target;
 }
 
 static const char *rawdata_get_link_sha256(struct dentry *dentry,
                                          struct inode *inode,
                                          struct delayed_call *done)
 {
         return rawdata_get_link_base(dentry, inode, done, "sha256");
 }
 
 static const char *rawdata_get_link_abi(struct dentry *dentry,
                                         struct inode *inode,
                                         struct delayed_call *done)
 {
         return rawdata_get_link_base(dentry, inode, done, "abi");
 }
 
 static const char *rawdata_get_link_data(struct dentry *dentry,
                                          struct inode *inode,
                                          struct delayed_call *done)
 {
         return rawdata_get_link_base(dentry, inode, done, "raw_data");
 }
 
 static const struct inode_operations rawdata_link_sha256_iops = {
         .get_link       = rawdata_get_link_sha256,
 };
 
 static const struct inode_operations rawdata_link_abi_iops = {
         .get_link       = rawdata_get_link_abi,
 };
 static const struct inode_operations rawdata_link_data_iops = {
         .get_link       = rawdata_get_link_data,
 };
 #endif /* CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */
 
 /*
  * Requires: @profile->ns->lock held
  */
 int __aafs_profile_mkdir(struct aa_profile *profile, struct dentry *parent)
 {
         struct aa_profile *child;
         struct dentry *dent = NULL, *dir;
         int error;
 
         AA_BUG(!profile);
         AA_BUG(!mutex_is_locked(&profiles_ns(profile)->lock));
 
         if (!parent) {
                 struct aa_profile *p;
                 p = aa_deref_parent(profile);
                 dent = prof_dir(p);
                 if (!dent) {
                         error = -ENOENT;
                         goto fail2;
                 }
                 /* adding to parent that previously didn't have children */
                 dent = aafs_create_dir("profiles", dent);
                 if (IS_ERR(dent))
                         goto fail;
                 prof_child_dir(p) = parent = dent;
         }
 
         if (!profile->dirname) {
                 int len, id_len;
                 len = mangle_name(profile->base.name, NULL);
                 id_len = snprintf(NULL, 0, ".%ld", profile->ns->uniq_id);
 
                 profile->dirname = kmalloc(len + id_len + 1, GFP_KERNEL);
                 if (!profile->dirname) {
                         error = -ENOMEM;
                         goto fail2;
                 }
 
                 mangle_name(profile->base.name, profile->dirname);
                 sprintf(profile->dirname + len, ".%ld", profile->ns->uniq_id++);
         }
 
         dent = aafs_create_dir(profile->dirname, parent);
         if (IS_ERR(dent))
                 goto fail;
         prof_dir(profile) = dir = dent;
 
         dent = create_profile_file(dir, "name", profile,
                                    &seq_profile_name_fops);
         if (IS_ERR(dent))
                 goto fail;
         profile->dents[AAFS_PROF_NAME] = dent;
 
         dent = create_profile_file(dir, "mode", profile,
                                    &seq_profile_mode_fops);
         if (IS_ERR(dent))
                 goto fail;
         profile->dents[AAFS_PROF_MODE] = dent;
 
         dent = create_profile_file(dir, "attach", profile,
                                    &seq_profile_attach_fops);
         if (IS_ERR(dent))
                 goto fail;
         profile->dents[AAFS_PROF_ATTACH] = dent;
 
         if (profile->hash) {
                 dent = create_profile_file(dir, "sha256", profile,
                                            &seq_profile_hash_fops);
                 if (IS_ERR(dent))
                         goto fail;
                 profile->dents[AAFS_PROF_HASH] = dent;
         }
 
 #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
         if (profile->rawdata) {
                 if (aa_g_hash_policy) {
                         dent = aafs_create("raw_sha256", S_IFLNK | 0444, dir,
                                            profile->label.proxy, NULL, NULL,
                                            &rawdata_link_sha256_iops);
                         if (IS_ERR(dent))
                                 goto fail;
                         aa_get_proxy(profile->label.proxy);
                         profile->dents[AAFS_PROF_RAW_HASH] = dent;
                 }
                 dent = aafs_create("raw_abi", S_IFLNK | 0444, dir,
                                    profile->label.proxy, NULL, NULL,
                                    &rawdata_link_abi_iops);
                 if (IS_ERR(dent))
                         goto fail;
                 aa_get_proxy(profile->label.proxy);
                 profile->dents[AAFS_PROF_RAW_ABI] = dent;
 
                 dent = aafs_create("raw_data", S_IFLNK | 0444, dir,
                                    profile->label.proxy, NULL, NULL,
                                    &rawdata_link_data_iops);
                 if (IS_ERR(dent))
                         goto fail;
                 aa_get_proxy(profile->label.proxy);
                 profile->dents[AAFS_PROF_RAW_DATA] = dent;
         }
 #endif /*CONFIG_SECURITY_APPARMOR_EXPORT_BINARY */
 
         list_for_each_entry(child, &profile->base.profiles, base.list) {
                 error = __aafs_profile_mkdir(child, prof_child_dir(profile));
                 if (error)
                         goto fail2;
         }
 
         return 0;
 
 fail:
         error = PTR_ERR(dent);
 
 fail2:
         __aafs_profile_rmdir(profile);
 
         return error;
 }
 
 static int ns_mkdir_op(struct mnt_idmap *idmap, struct inode *dir,
                        struct dentry *dentry, umode_t mode)
 {
         struct aa_ns *ns, *parent;
         /* TODO: improve permission check */
         struct aa_label *label;
         int error;
 
         label = begin_current_label_crit_section();
         error = aa_may_manage_policy(current_cred(), label, NULL,
                                      AA_MAY_LOAD_POLICY);
         end_current_label_crit_section(label);
         if (error)
                 return error;
 
         parent = aa_get_ns(dir->i_private);
         AA_BUG(d_inode(ns_subns_dir(parent)) != dir);
 
         /* we have to unlock and then relock to get locking order right
          * for pin_fs
          */
         inode_unlock(dir);
         error = simple_pin_fs(&aafs_ops, &aafs_mnt, &aafs_count);
         mutex_lock_nested(&parent->lock, parent->level);
         inode_lock_nested(dir, I_MUTEX_PARENT);
         if (error)
                 goto out;
 
         error = __aafs_setup_d_inode(dir, dentry, mode | S_IFDIR,  NULL,
                                      NULL, NULL, NULL);
         if (error)
                 goto out_pin;
 
         ns = __aa_find_or_create_ns(parent, READ_ONCE(dentry->d_name.name),
                                     dentry);
         if (IS_ERR(ns)) {
                 error = PTR_ERR(ns);
                 ns = NULL;
         }
 
         aa_put_ns(ns);          /* list ref remains */
 out_pin:
         if (error)
                 simple_release_fs(&aafs_mnt, &aafs_count);
 out:
         mutex_unlock(&parent->lock);
         aa_put_ns(parent);
 
         return error;
 }
 
 static int ns_rmdir_op(struct inode *dir, struct dentry *dentry)
 {
         struct aa_ns *ns, *parent;
         /* TODO: improve permission check */
         struct aa_label *label;
         int error;
 
         label = begin_current_label_crit_section();
         error = aa_may_manage_policy(current_cred(), label, NULL,
                                      AA_MAY_LOAD_POLICY);
         end_current_label_crit_section(label);
         if (error)
                 return error;
 
         parent = aa_get_ns(dir->i_private);
         /* rmdir calls the generic securityfs functions to remove files
          * from the apparmor dir. It is up to the apparmor ns locking
          * to avoid races.
          */
         inode_unlock(dir);
         inode_unlock(dentry->d_inode);
 
         mutex_lock_nested(&parent->lock, parent->level);
         ns = aa_get_ns(__aa_findn_ns(&parent->sub_ns, dentry->d_name.name,
                                      dentry->d_name.len));
         if (!ns) {
                 error = -ENOENT;
                 goto out;
         }
         AA_BUG(ns_dir(ns) != dentry);
 
         __aa_remove_ns(ns);
         aa_put_ns(ns);
 
 out:
         mutex_unlock(&parent->lock);
         inode_lock_nested(dir, I_MUTEX_PARENT);
         inode_lock(dentry->d_inode);
         aa_put_ns(parent);
 
         return error;
 }
 
 static const struct inode_operations ns_dir_inode_operations = {
         .lookup         = simple_lookup,
         .mkdir          = ns_mkdir_op,
         .rmdir          = ns_rmdir_op,
 };
 
 static void __aa_fs_list_remove_rawdata(struct aa_ns *ns)
 {
         struct aa_loaddata *ent, *tmp;
 
         AA_BUG(!mutex_is_locked(&ns->lock));
 
         list_for_each_entry_safe(ent, tmp, &ns->rawdata_list, list)
                 __aa_fs_remove_rawdata(ent);
 }
 
 /*
  *
  * Requires: @ns->lock held
  */
 void __aafs_ns_rmdir(struct aa_ns *ns)
 {
         struct aa_ns *sub;
         struct aa_profile *child;
         int i;
 
         if (!ns)
                 return;
         AA_BUG(!mutex_is_locked(&ns->lock));
 
         list_for_each_entry(child, &ns->base.profiles, base.list)
                 __aafs_profile_rmdir(child);
 
         list_for_each_entry(sub, &ns->sub_ns, base.list) {
                 mutex_lock_nested(&sub->lock, sub->level);
                 __aafs_ns_rmdir(sub);
                 mutex_unlock(&sub->lock);
         }
 
         __aa_fs_list_remove_rawdata(ns);
 
         if (ns_subns_dir(ns)) {
                 sub = d_inode(ns_subns_dir(ns))->i_private;
                 aa_put_ns(sub);
         }
         if (ns_subload(ns)) {
                 sub = d_inode(ns_subload(ns))->i_private;
                 aa_put_ns(sub);
         }
         if (ns_subreplace(ns)) {
                 sub = d_inode(ns_subreplace(ns))->i_private;
                 aa_put_ns(sub);
         }
         if (ns_subremove(ns)) {
                 sub = d_inode(ns_subremove(ns))->i_private;
                 aa_put_ns(sub);
         }
         if (ns_subrevision(ns)) {
                 sub = d_inode(ns_subrevision(ns))->i_private;
                 aa_put_ns(sub);
         }
 
         for (i = AAFS_NS_SIZEOF - 1; i >= 0; --i) {
                 aafs_remove(ns->dents[i]);
                 ns->dents[i] = NULL;
         }
 }
 
 /* assumes cleanup in caller */
 static int __aafs_ns_mkdir_entries(struct aa_ns *ns, struct dentry *dir)
 {
         struct dentry *dent;
 
         AA_BUG(!ns);
         AA_BUG(!dir);
 
         dent = aafs_create_dir("profiles", dir);
         if (IS_ERR(dent))
                 return PTR_ERR(dent);
         ns_subprofs_dir(ns) = dent;
 
         dent = aafs_create_dir("raw_data", dir);
         if (IS_ERR(dent))
                 return PTR_ERR(dent);
         ns_subdata_dir(ns) = dent;
 
         dent = aafs_create_file("revision", 0444, dir, ns,
                                 &aa_fs_ns_revision_fops);
         if (IS_ERR(dent))
                 return PTR_ERR(dent);
         aa_get_ns(ns);
         ns_subrevision(ns) = dent;
 
         dent = aafs_create_file(".load", 0640, dir, ns,
                                       &aa_fs_profile_load);
         if (IS_ERR(dent))
                 return PTR_ERR(dent);
         aa_get_ns(ns);
         ns_subload(ns) = dent;
 
         dent = aafs_create_file(".replace", 0640, dir, ns,
                                       &aa_fs_profile_replace);
         if (IS_ERR(dent))
                 return PTR_ERR(dent);
         aa_get_ns(ns);
         ns_subreplace(ns) = dent;
 
         dent = aafs_create_file(".remove", 0640, dir, ns,
                                       &aa_fs_profile_remove);
         if (IS_ERR(dent))
                 return PTR_ERR(dent);
         aa_get_ns(ns);
         ns_subremove(ns) = dent;
 
           /* use create_dentry so we can supply private data */
         dent = aafs_create("namespaces", S_IFDIR | 0755, dir, ns, NULL, NULL,
                            &ns_dir_inode_operations);
         if (IS_ERR(dent))
                 return PTR_ERR(dent);
         aa_get_ns(ns);
         ns_subns_dir(ns) = dent;
 
         return 0;
 }
 
 /*
  * Requires: @ns->lock held
  */
 int __aafs_ns_mkdir(struct aa_ns *ns, struct dentry *parent, const char *name,
                     struct dentry *dent)
 {
         struct aa_ns *sub;
         struct aa_profile *child;
         struct dentry *dir;
         int error;
 
         AA_BUG(!ns);
         AA_BUG(!parent);
         AA_BUG(!mutex_is_locked(&ns->lock));
 
         if (!name)
                 name = ns->base.name;
 
         if (!dent) {
                 /* create ns dir if it doesn't already exist */
                 dent = aafs_create_dir(name, parent);
                 if (IS_ERR(dent))
                         goto fail;
         } else
                 dget(dent);
         ns_dir(ns) = dir = dent;
         error = __aafs_ns_mkdir_entries(ns, dir);
         if (error)
                 goto fail2;
 
         /* profiles */
         list_for_each_entry(child, &ns->base.profiles, base.list) {
                 error = __aafs_profile_mkdir(child, ns_subprofs_dir(ns));
                 if (error)
                         goto fail2;
         }
 
         /* subnamespaces */
         list_for_each_entry(sub, &ns->sub_ns, base.list) {
                 mutex_lock_nested(&sub->lock, sub->level);
                 error = __aafs_ns_mkdir(sub, ns_subns_dir(ns), NULL, NULL);
                 mutex_unlock(&sub->lock);
                 if (error)
                         goto fail2;
         }
 
         return 0;
 
 fail:
         error = PTR_ERR(dent);
 
 fail2:
         __aafs_ns_rmdir(ns);
 
         return error;
 }
 
 /**
  * __next_ns - find the next namespace to list
  * @root: root namespace to stop search at (NOT NULL)
  * @ns: current ns position (NOT NULL)
  *
  * Find the next namespace from @ns under @root and handle all locking needed
  * while switching current namespace.
  *
  * Returns: next namespace or NULL if at last namespace under @root
  * Requires: ns->parent->lock to be held
  * NOTE: will not unlock root->lock
  */
 static struct aa_ns *__next_ns(struct aa_ns *root, struct aa_ns *ns)
 {
         struct aa_ns *parent, *next;
 
         AA_BUG(!root);
         AA_BUG(!ns);
         AA_BUG(ns != root && !mutex_is_locked(&ns->parent->lock));
 
         /* is next namespace a child */
         if (!list_empty(&ns->sub_ns)) {
                 next = list_first_entry(&ns->sub_ns, typeof(*ns), base.list);
                 mutex_lock_nested(&next->lock, next->level);
                 return next;
         }
 
         /* check if the next ns is a sibling, parent, gp, .. */
         parent = ns->parent;
         while (ns != root) {
                 mutex_unlock(&ns->lock);
                 next = list_next_entry(ns, base.list);
                 if (!list_entry_is_head(next, &parent->sub_ns, base.list)) {
                         mutex_lock_nested(&next->lock, next->level);
                         return next;
                 }
                 ns = parent;
                 parent = parent->parent;
         }
 
         return NULL;
 }
 
 /**
  * __first_profile - find the first profile in a namespace
  * @root: namespace that is root of profiles being displayed (NOT NULL)
  * @ns: namespace to start in   (NOT NULL)
  *
  * Returns: unrefcounted profile or NULL if no profile
  * Requires: profile->ns.lock to be held
  */
 static struct aa_profile *__first_profile(struct aa_ns *root,
                                           struct aa_ns *ns)
 {
         AA_BUG(!root);
         AA_BUG(ns && !mutex_is_locked(&ns->lock));
 
         for (; ns; ns = __next_ns(root, ns)) {
                 if (!list_empty(&ns->base.profiles))
                         return list_first_entry(&ns->base.profiles,
                                                 struct aa_profile, base.list);
         }
         return NULL;
 }
 
 /**
  * __next_profile - step to the next profile in a profile tree
  * @p: current profile in tree (NOT NULL)
  *
  * Perform a depth first traversal on the profile tree in a namespace
  *
  * Returns: next profile or NULL if done
  * Requires: profile->ns.lock to be held
  */
 static struct aa_profile *__next_profile(struct aa_profile *p)
 {
         struct aa_profile *parent;
         struct aa_ns *ns = p->ns;
 
         AA_BUG(!mutex_is_locked(&profiles_ns(p)->lock));
 
         /* is next profile a child */
         if (!list_empty(&p->base.profiles))
                 return list_first_entry(&p->base.profiles, typeof(*p),
                                         base.list);
 
         /* is next profile a sibling, parent sibling, gp, sibling, .. */
         parent = rcu_dereference_protected(p->parent,
                                            mutex_is_locked(&p->ns->lock));
         while (parent) {
                 p = list_next_entry(p, base.list);
                 if (!list_entry_is_head(p, &parent->base.profiles, base.list))
                         return p;
                 p = parent;
                 parent = rcu_dereference_protected(parent->parent,
                                             mutex_is_locked(&parent->ns->lock));
         }
 
         /* is next another profile in the namespace */
         p = list_next_entry(p, base.list);
         if (!list_entry_is_head(p, &ns->base.profiles, base.list))
                 return p;
 
         return NULL;
 }
 
 /**
  * next_profile - step to the next profile in where ever it may be
  * @root: root namespace  (NOT NULL)
  * @profile: current profile  (NOT NULL)
  *
  * Returns: next profile or NULL if there isn't one
  */
 static struct aa_profile *next_profile(struct aa_ns *root,
                                        struct aa_profile *profile)
 {
         struct aa_profile *next = __next_profile(profile);
         if (next)
                 return next;
 
         /* finished all profiles in namespace move to next namespace */
         return __first_profile(root, __next_ns(root, profile->ns));
 }
 
 /**
  * p_start - start a depth first traversal of profile tree
  * @f: seq_file to fill
  * @pos: current position
  *
  * Returns: first profile under current namespace or NULL if none found
  *
  * acquires first ns->lock
  */
 static void *p_start(struct seq_file *f, loff_t *pos)
 {
         struct aa_profile *profile = NULL;
         struct aa_ns *root = aa_get_current_ns();
         loff_t l = *pos;
         f->private = root;
 
         /* find the first profile */
         mutex_lock_nested(&root->lock, root->level);
         profile = __first_profile(root, root);
 
         /* skip to position */
         for (; profile && l > 0; l--)
                 profile = next_profile(root, profile);
 
         return profile;
 }
 
 /**
  * p_next - read the next profile entry
  * @f: seq_file to fill
  * @p: profile previously returned
  * @pos: current position
  *
  * Returns: next profile after @p or NULL if none
  *
  * may acquire/release locks in namespace tree as necessary
  */
 static void *p_next(struct seq_file *f, void *p, loff_t *pos)
 {
         struct aa_profile *profile = p;
         struct aa_ns *ns = f->private;
         (*pos)++;
 
         return next_profile(ns, profile);
 }
 
 /**
  * p_stop - stop depth first traversal
  * @f: seq_file we are filling
  * @p: the last profile writen
  *
  * Release all locking done by p_start/p_next on namespace tree
  */
 static void p_stop(struct seq_file *f, void *p)
 {
         struct aa_profile *profile = p;
         struct aa_ns *root = f->private, *ns;
 
         if (profile) {
                 for (ns = profile->ns; ns && ns != root; ns = ns->parent)
                         mutex_unlock(&ns->lock);
         }
         mutex_unlock(&root->lock);
         aa_put_ns(root);
 }
 
 /**
  * seq_show_profile - show a profile entry
  * @f: seq_file to file
  * @p: current position (profile)    (NOT NULL)
  *
  * Returns: error on failure
  */
 static int seq_show_profile(struct seq_file *f, void *p)
 {
         struct aa_profile *profile = (struct aa_profile *)p;
         struct aa_ns *root = f->private;
 
         aa_label_seq_xprint(f, root, &profile->label,
                             FLAG_SHOW_MODE | FLAG_VIEW_SUBNS, GFP_KERNEL);
         seq_putc(f, '\n');
 
         return 0;
 }
 
 static const struct seq_operations aa_sfs_profiles_op = {
         .start = p_start,
         .next = p_next,
         .stop = p_stop,
         .show = seq_show_profile,
 };
 
 static int profiles_open(struct inode *inode, struct file *file)
 {
         if (!aa_current_policy_view_capable(NULL))
                 return -EACCES;
 
         return seq_open(file, &aa_sfs_profiles_op);
 }
 
 static int profiles_release(struct inode *inode, struct file *file)
 {
         return seq_release(inode, file);
 }
 
 static const struct file_operations aa_sfs_profiles_fops = {
         .open = profiles_open,
         .read = seq_read,
         .llseek = seq_lseek,
         .release = profiles_release,
 };
 
 
 /** Base file system setup **/
 static struct aa_sfs_entry aa_sfs_entry_file[] = {
         AA_SFS_FILE_STRING("mask",
                            "create read write exec append mmap_exec link lock"),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_ptrace[] = {
         AA_SFS_FILE_STRING("mask", "read trace"),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_signal[] = {
         AA_SFS_FILE_STRING("mask", AA_SFS_SIG_MASK),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_attach[] = {
         AA_SFS_FILE_BOOLEAN("xattr", 1),
         { }
 };
 static struct aa_sfs_entry aa_sfs_entry_domain[] = {
         AA_SFS_FILE_BOOLEAN("change_hat",       1),
         AA_SFS_FILE_BOOLEAN("change_hatv",      1),
         AA_SFS_FILE_BOOLEAN("change_onexec",    1),
         AA_SFS_FILE_BOOLEAN("change_profile",   1),
         AA_SFS_FILE_BOOLEAN("stack",            1),
         AA_SFS_FILE_BOOLEAN("fix_binfmt_elf_mmap",      1),
         AA_SFS_FILE_BOOLEAN("post_nnp_subset",  1),
         AA_SFS_FILE_BOOLEAN("computed_longest_left",    1),
         AA_SFS_DIR("attach_conditions",         aa_sfs_entry_attach),
         AA_SFS_FILE_BOOLEAN("disconnected.path",            1),
         AA_SFS_FILE_STRING("version", "1.2"),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_unconfined[] = {
         AA_SFS_FILE_BOOLEAN("change_profile", 1),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_versions[] = {
         AA_SFS_FILE_BOOLEAN("v5",       1),
         AA_SFS_FILE_BOOLEAN("v6",       1),
         AA_SFS_FILE_BOOLEAN("v7",       1),
         AA_SFS_FILE_BOOLEAN("v8",       1),
         AA_SFS_FILE_BOOLEAN("v9",       1),
         { }
 };
 
 #define PERMS32STR "allow deny subtree cond kill complain prompt audit quiet hide xindex tag label"
 static struct aa_sfs_entry aa_sfs_entry_policy[] = {
         AA_SFS_DIR("versions",                  aa_sfs_entry_versions),
         AA_SFS_FILE_BOOLEAN("set_load",         1),
         /* number of out of band transitions supported */
         AA_SFS_FILE_U64("outofband",            MAX_OOB_SUPPORTED),
         AA_SFS_FILE_U64("permstable32_version", 1),
         AA_SFS_FILE_STRING("permstable32", PERMS32STR),
         AA_SFS_DIR("unconfined_restrictions",   aa_sfs_entry_unconfined),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_mount[] = {
         AA_SFS_FILE_STRING("mask", "mount umount pivot_root"),
         AA_SFS_FILE_STRING("move_mount", "detached"),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_ns[] = {
         AA_SFS_FILE_BOOLEAN("profile",          1),
         AA_SFS_FILE_BOOLEAN("pivot_root",       0),
         AA_SFS_FILE_STRING("mask", "userns_create"),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_query_label[] = {
         AA_SFS_FILE_STRING("perms", "allow deny audit quiet"),
         AA_SFS_FILE_BOOLEAN("data",             1),
         AA_SFS_FILE_BOOLEAN("multi_transaction",        1),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_query[] = {
         AA_SFS_DIR("label",                     aa_sfs_entry_query_label),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_io_uring[] = {
         AA_SFS_FILE_STRING("mask", "sqpoll override_creds"),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_features[] = {
         AA_SFS_DIR("policy",                    aa_sfs_entry_policy),
         AA_SFS_DIR("domain",                    aa_sfs_entry_domain),
         AA_SFS_DIR("file",                      aa_sfs_entry_file),
         AA_SFS_DIR("network_v8",                aa_sfs_entry_network),
         AA_SFS_DIR("mount",                     aa_sfs_entry_mount),
         AA_SFS_DIR("namespaces",                aa_sfs_entry_ns),
         AA_SFS_FILE_U64("capability",           VFS_CAP_FLAGS_MASK),
         AA_SFS_DIR("rlimit",                    aa_sfs_entry_rlimit),
         AA_SFS_DIR("caps",                      aa_sfs_entry_caps),
         AA_SFS_DIR("ptrace",                    aa_sfs_entry_ptrace),
         AA_SFS_DIR("signal",                    aa_sfs_entry_signal),
         AA_SFS_DIR("query",                     aa_sfs_entry_query),
         AA_SFS_DIR("io_uring",                  aa_sfs_entry_io_uring),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry_apparmor[] = {
         AA_SFS_FILE_FOPS(".access", 0666, &aa_sfs_access),
         AA_SFS_FILE_FOPS(".stacked", 0444, &seq_ns_stacked_fops),
         AA_SFS_FILE_FOPS(".ns_stacked", 0444, &seq_ns_nsstacked_fops),
         AA_SFS_FILE_FOPS(".ns_level", 0444, &seq_ns_level_fops),
         AA_SFS_FILE_FOPS(".ns_name", 0444, &seq_ns_name_fops),
         AA_SFS_FILE_FOPS("profiles", 0444, &aa_sfs_profiles_fops),
         AA_SFS_FILE_FOPS("raw_data_compression_level_min", 0444, &seq_ns_compress_min_fops),
         AA_SFS_FILE_FOPS("raw_data_compression_level_max", 0444, &seq_ns_compress_max_fops),
         AA_SFS_DIR("features", aa_sfs_entry_features),
         { }
 };
 
 static struct aa_sfs_entry aa_sfs_entry =
         AA_SFS_DIR("apparmor", aa_sfs_entry_apparmor);
 
 /**
  * entry_create_file - create a file entry in the apparmor securityfs
  * @fs_file: aa_sfs_entry to build an entry for (NOT NULL)
  * @parent: the parent dentry in the securityfs
  *
  * Use entry_remove_file to remove entries created with this fn.
  */
 static int __init entry_create_file(struct aa_sfs_entry *fs_file,
                                     struct dentry *parent)
 {
         int error = 0;
 
         fs_file->dentry = securityfs_create_file(fs_file->name,
                                                  S_IFREG | fs_file->mode,
                                                  parent, fs_file,
                                                  fs_file->file_ops);
         if (IS_ERR(fs_file->dentry)) {
                 error = PTR_ERR(fs_file->dentry);
                 fs_file->dentry = NULL;
         }
         return error;
 }
 
 static void __init entry_remove_dir(struct aa_sfs_entry *fs_dir);
 /**
  * entry_create_dir - recursively create a directory entry in the securityfs
  * @fs_dir: aa_sfs_entry (and all child entries) to build (NOT NULL)
  * @parent: the parent dentry in the securityfs
  *
  * Use entry_remove_dir to remove entries created with this fn.
  */
 static int __init entry_create_dir(struct aa_sfs_entry *fs_dir,
                                    struct dentry *parent)
 {
         struct aa_sfs_entry *fs_file;
         struct dentry *dir;
         int error;
 
         dir = securityfs_create_dir(fs_dir->name, parent);
         if (IS_ERR(dir))
                 return PTR_ERR(dir);
         fs_dir->dentry = dir;
 
         for (fs_file = fs_dir->v.files; fs_file && fs_file->name; ++fs_file) {
                 if (fs_file->v_type == AA_SFS_TYPE_DIR)
                         error = entry_create_dir(fs_file, fs_dir->dentry);
                 else
                         error = entry_create_file(fs_file, fs_dir->dentry);
                 if (error)
                         goto failed;
         }
 
         return 0;
 
 failed:
         entry_remove_dir(fs_dir);
 
         return error;
 }
 
 /**
  * entry_remove_file - drop a single file entry in the apparmor securityfs
  * @fs_file: aa_sfs_entry to detach from the securityfs (NOT NULL)
  */
 static void __init entry_remove_file(struct aa_sfs_entry *fs_file)
 {
         if (!fs_file->dentry)
                 return;
 
         securityfs_remove(fs_file->dentry);
         fs_file->dentry = NULL;
 }
 
 /**
  * entry_remove_dir - recursively drop a directory entry from the securityfs
  * @fs_dir: aa_sfs_entry (and all child entries) to detach (NOT NULL)
  */
 static void __init entry_remove_dir(struct aa_sfs_entry *fs_dir)
 {
         struct aa_sfs_entry *fs_file;
 
         for (fs_file = fs_dir->v.files; fs_file && fs_file->name; ++fs_file) {
                 if (fs_file->v_type == AA_SFS_TYPE_DIR)
                         entry_remove_dir(fs_file);
                 else
                         entry_remove_file(fs_file);
         }
 
         entry_remove_file(fs_dir);
 }
 
 /**
  * aa_destroy_aafs - cleanup and free aafs
  *
  * releases dentries allocated by aa_create_aafs
  */
 void __init aa_destroy_aafs(void)
 {
         entry_remove_dir(&aa_sfs_entry);
 }
 
 
 #define NULL_FILE_NAME ".null"
 struct path aa_null;
 
 static int aa_mk_null_file(struct dentry *parent)
 {
         struct vfsmount *mount = NULL;
         struct dentry *dentry;
         struct inode *inode;
         int count = 0;
         int error = simple_pin_fs(parent->d_sb->s_type, &mount, &count);
 
         if (error)
                 return error;
 
         inode_lock(d_inode(parent));
         dentry = lookup_one_len(NULL_FILE_NAME, parent, strlen(NULL_FILE_NAME));
         if (IS_ERR(dentry)) {
                 error = PTR_ERR(dentry);
                 goto out;
         }
         inode = new_inode(parent->d_inode->i_sb);
         if (!inode) {
                 error = -ENOMEM;
                 goto out1;
         }
 
         inode->i_ino = get_next_ino();
         inode->i_mode = S_IFCHR | S_IRUGO | S_IWUGO;
         simple_inode_init_ts(inode);
         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO,
                            MKDEV(MEM_MAJOR, 3));
         d_instantiate(dentry, inode);
         aa_null.dentry = dget(dentry);
         aa_null.mnt = mntget(mount);
 
         error = 0;
 
 out1:
         dput(dentry);
 out:
         inode_unlock(d_inode(parent));
         simple_release_fs(&mount, &count);
         return error;
 }
 
 
 
 static const char *policy_get_link(struct dentry *dentry,
                                    struct inode *inode,
                                    struct delayed_call *done)
 {
         struct aa_ns *ns;
         struct path path;
         int error;
 
         if (!dentry)
                 return ERR_PTR(-ECHILD);
 
         ns = aa_get_current_ns();
         path.mnt = mntget(aafs_mnt);
         path.dentry = dget(ns_dir(ns));
         error = nd_jump_link(&path);
         aa_put_ns(ns);
 
         return ERR_PTR(error);
 }
 
 static int policy_readlink(struct dentry *dentry, char __user *buffer,
                            int buflen)
 {
         char name[32];
         int res;
 
         res = snprintf(name, sizeof(name), "%s:[%lu]", AAFS_NAME,
                        d_inode(dentry)->i_ino);
         if (res > 0 && res < sizeof(name))
                 res = readlink_copy(buffer, buflen, name);
         else
                 res = -ENOENT;
 
         return res;
 }
 
 static const struct inode_operations policy_link_iops = {
         .readlink       = policy_readlink,
         .get_link       = policy_get_link,
 };
 
 
 /**
  * aa_create_aafs - create the apparmor security filesystem
  *
  * dentries created here are released by aa_destroy_aafs
  *
  * Returns: error on failure
  */
 static int __init aa_create_aafs(void)
 {
         struct dentry *dent;
         int error;
 
         if (!apparmor_initialized)
                 return 0;
 
         if (aa_sfs_entry.dentry) {
                 AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
                 return -EEXIST;
         }
 
         /* setup apparmorfs used to virtualize policy/ */
         aafs_mnt = kern_mount(&aafs_ops);
         if (IS_ERR(aafs_mnt))
                 panic("can't set apparmorfs up\n");
         aafs_mnt->mnt_sb->s_flags &= ~SB_NOUSER;
 
         /* Populate fs tree. */
         error = entry_create_dir(&aa_sfs_entry, NULL);
         if (error)
                 goto error;
 
         dent = securityfs_create_file(".load", 0666, aa_sfs_entry.dentry,
                                       NULL, &aa_fs_profile_load);
         if (IS_ERR(dent))
                 goto dent_error;
         ns_subload(root_ns) = dent;
 
         dent = securityfs_create_file(".replace", 0666, aa_sfs_entry.dentry,
                                       NULL, &aa_fs_profile_replace);
         if (IS_ERR(dent))
                 goto dent_error;
         ns_subreplace(root_ns) = dent;
 
         dent = securityfs_create_file(".remove", 0666, aa_sfs_entry.dentry,
                                       NULL, &aa_fs_profile_remove);
         if (IS_ERR(dent))
                 goto dent_error;
         ns_subremove(root_ns) = dent;
 
         dent = securityfs_create_file("revision", 0444, aa_sfs_entry.dentry,
                                       NULL, &aa_fs_ns_revision_fops);
         if (IS_ERR(dent))
                 goto dent_error;
         ns_subrevision(root_ns) = dent;
 
         /* policy tree referenced by magic policy symlink */
         mutex_lock_nested(&root_ns->lock, root_ns->level);
         error = __aafs_ns_mkdir(root_ns, aafs_mnt->mnt_root, ".policy",
                                 aafs_mnt->mnt_root);
         mutex_unlock(&root_ns->lock);
         if (error)
                 goto error;
 
         /* magic symlink similar to nsfs redirects based on task policy */
         dent = securityfs_create_symlink("policy", aa_sfs_entry.dentry,
                                          NULL, &policy_link_iops);
         if (IS_ERR(dent))
                 goto dent_error;
 
         error = aa_mk_null_file(aa_sfs_entry.dentry);
         if (error)
                 goto error;
 
         /* TODO: add default profile to apparmorfs */
 
         /* Report that AppArmor fs is enabled */
         aa_info_message("AppArmor Filesystem Enabled");
         return 0;
 
 dent_error:
         error = PTR_ERR(dent);
 error:
         aa_destroy_aafs();
         AA_ERROR("Error creating AppArmor securityfs\n");
         return error;
 }
 
 fs_initcall(aa_create_aafs);
 

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