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linux-next/security/apparmor/apparmorfs.c
Linus Torvalds 6aee4badd8 Merge branch 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull openat2 support from Al Viro:
 "This is the openat2() series from Aleksa Sarai.

  I'm afraid that the rest of namei stuff will have to wait - it got
  zero review the last time I'd posted #work.namei, and there had been a
  leak in the posted series I'd caught only last weekend. I was going to
  repost it on Monday, but the window opened and the odds of getting any
  review during that... Oh, well.

  Anyway, openat2 part should be ready; that _did_ get sane amount of
  review and public testing, so here it comes"

From Aleksa's description of the series:
 "For a very long time, extending openat(2) with new features has been
  incredibly frustrating. This stems from the fact that openat(2) is
  possibly the most famous counter-example to the mantra "don't silently
  accept garbage from userspace" -- it doesn't check whether unknown
  flags are present[1].

  This means that (generally) the addition of new flags to openat(2) has
  been fraught with backwards-compatibility issues (O_TMPFILE has to be
  defined as __O_TMPFILE|O_DIRECTORY|[O_RDWR or O_WRONLY] to ensure old
  kernels gave errors, since it's insecure to silently ignore the
  flag[2]). All new security-related flags therefore have a tough road
  to being added to openat(2).

  Furthermore, the need for some sort of control over VFS's path
  resolution (to avoid malicious paths resulting in inadvertent
  breakouts) has been a very long-standing desire of many userspace
  applications.

  This patchset is a revival of Al Viro's old AT_NO_JUMPS[3] patchset
  (which was a variant of David Drysdale's O_BENEATH patchset[4] which
  was a spin-off of the Capsicum project[5]) with a few additions and
  changes made based on the previous discussion within [6] as well as
  others I felt were useful.

  In line with the conclusions of the original discussion of
  AT_NO_JUMPS, the flag has been split up into separate flags. However,
  instead of being an openat(2) flag it is provided through a new
  syscall openat2(2) which provides several other improvements to the
  openat(2) interface (see the patch description for more details). The
  following new LOOKUP_* flags are added:

  LOOKUP_NO_XDEV:

     Blocks all mountpoint crossings (upwards, downwards, or through
     absolute links). Absolute pathnames alone in openat(2) do not
     trigger this. Magic-link traversal which implies a vfsmount jump is
     also blocked (though magic-link jumps on the same vfsmount are
     permitted).

  LOOKUP_NO_MAGICLINKS:

     Blocks resolution through /proc/$pid/fd-style links. This is done
     by blocking the usage of nd_jump_link() during resolution in a
     filesystem. The term "magic-links" is used to match with the only
     reference to these links in Documentation/, but I'm happy to change
     the name.

     It should be noted that this is different to the scope of
     ~LOOKUP_FOLLOW in that it applies to all path components. However,
     you can do openat2(NO_FOLLOW|NO_MAGICLINKS) on a magic-link and it
     will *not* fail (assuming that no parent component was a
     magic-link), and you will have an fd for the magic-link.

     In order to correctly detect magic-links, the introduction of a new
     LOOKUP_MAGICLINK_JUMPED state flag was required.

  LOOKUP_BENEATH:

     Disallows escapes to outside the starting dirfd's
     tree, using techniques such as ".." or absolute links. Absolute
     paths in openat(2) are also disallowed.

     Conceptually this flag is to ensure you "stay below" a certain
     point in the filesystem tree -- but this requires some additional
     to protect against various races that would allow escape using
     "..".

     Currently LOOKUP_BENEATH implies LOOKUP_NO_MAGICLINKS, because it
     can trivially beam you around the filesystem (breaking the
     protection). In future, there might be similar safety checks done
     as in LOOKUP_IN_ROOT, but that requires more discussion.

  In addition, two new flags are added that expand on the above ideas:

  LOOKUP_NO_SYMLINKS:

     Does what it says on the tin. No symlink resolution is allowed at
     all, including magic-links. Just as with LOOKUP_NO_MAGICLINKS this
     can still be used with NOFOLLOW to open an fd for the symlink as
     long as no parent path had a symlink component.

  LOOKUP_IN_ROOT:

     This is an extension of LOOKUP_BENEATH that, rather than blocking
     attempts to move past the root, forces all such movements to be
     scoped to the starting point. This provides chroot(2)-like
     protection but without the cost of a chroot(2) for each filesystem
     operation, as well as being safe against race attacks that
     chroot(2) is not.

     If a race is detected (as with LOOKUP_BENEATH) then an error is
     generated, and similar to LOOKUP_BENEATH it is not permitted to
     cross magic-links with LOOKUP_IN_ROOT.

     The primary need for this is from container runtimes, which
     currently need to do symlink scoping in userspace[7] when opening
     paths in a potentially malicious container.

     There is a long list of CVEs that could have bene mitigated by
     having RESOLVE_THIS_ROOT (such as CVE-2017-1002101,
     CVE-2017-1002102, CVE-2018-15664, and CVE-2019-5736, just to name a
     few).

  In order to make all of the above more usable, I'm working on
  libpathrs[8] which is a C-friendly library for safe path resolution.
  It features a userspace-emulated backend if the kernel doesn't support
  openat2(2). Hopefully we can get userspace to switch to using it, and
  thus get openat2(2) support for free once it's ready.

  Future work would include implementing things like
  RESOLVE_NO_AUTOMOUNT and possibly a RESOLVE_NO_REMOTE (to allow
  programs to be sure they don't hit DoSes though stale NFS handles)"

* 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Documentation: path-lookup: include new LOOKUP flags
  selftests: add openat2(2) selftests
  open: introduce openat2(2) syscall
  namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution
  namei: LOOKUP_IN_ROOT: chroot-like scoped resolution
  namei: LOOKUP_BENEATH: O_BENEATH-like scoped resolution
  namei: LOOKUP_NO_XDEV: block mountpoint crossing
  namei: LOOKUP_NO_MAGICLINKS: block magic-link resolution
  namei: LOOKUP_NO_SYMLINKS: block symlink resolution
  namei: allow set_root() to produce errors
  namei: allow nd_jump_link() to produce errors
  nsfs: clean-up ns_get_path() signature to return int
  namei: only return -ECHILD from follow_dotdot_rcu()
2020-01-29 11:20:24 -08:00

2700 lines
65 KiB
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/zlib.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"
/*
* 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;
};
#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;
}
/**
* aa_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;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(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_create_symlink - create a symlink in the apparmorfs filesystem
* @name: name of dentry to create
* @parent: parent directory for this dentry
* @target: if symlink, symlink target string
* @private: private data
* @iops: struct of inode_operations that should be used
*
* If @target parameter is %NULL, then the @iops parameter needs to be
* setup to handle .readlink and .get_link inode_operations.
*/
static struct dentry *aafs_create_symlink(const char *name,
struct dentry *parent,
const char *target,
void *private,
const struct inode_operations *iops)
{
struct dentry *dent;
char *link = NULL;
if (target) {
if (!link)
return ERR_PTR(-ENOMEM);
}
dent = aafs_create(name, S_IFLNK | 0444, parent, private, link, NULL,
iops);
if (IS_ERR(dent))
kfree(link);
return dent;
}
/**
* 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)) {
kvfree(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(label, ns, mask);
if (error)
return error;
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_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(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, 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_perms tmp = { };
struct aa_dfa *dfa;
unsigned int state = 0;
if (profile_unconfined(profile))
return;
if (profile->file.dfa && *match_str == AA_CLASS_FILE) {
dfa = profile->file.dfa;
state = aa_dfa_match_len(dfa, profile->file.start,
match_str + 1, match_len - 1);
if (state) {
struct path_cond cond = { };
tmp = aa_compute_fperms(dfa, state, &cond);
}
} else if (profile->policy.dfa) {
if (!PROFILE_MEDIATES(profile, *match_str))
return; /* no change to current perms */
dfa = profile->policy.dfa;
state = aa_dfa_match_len(dfa, profile->policy.start[0],
match_str, match_len);
if (state)
aa_compute_perms(dfa, state, &tmp);
}
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[0];
};
#define MULTI_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct multi_transaction))
/* TODO: replace with per file lock */
static DEFINE_SPINLOCK(multi_transaction_lock);
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(&multi_transaction_lock);
old = (struct multi_transaction *) file->private_data;
file->private_data = new;
spin_unlock(&multi_transaction_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))
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(&multi_transaction_lock);
t = get_multi_transaction(file->private_data);
spin_unlock(&multi_transaction_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)
seq_printf(seq, "%s\n", profile->attach);
else if (profile->xmatch)
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;
}
SEQ_NS_FOPS(stacked);
SEQ_NS_FOPS(nsstacked);
SEQ_NS_FOPS(level);
SEQ_NS_FOPS(name);
/* policy/raw_data/ * file ops */
#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 deflate_decompress(char *src, size_t slen, char *dst, size_t dlen)
{
int error;
struct z_stream_s strm;
if (aa_g_rawdata_compression_level == 0) {
if (dlen < slen)
return -EINVAL;
memcpy(dst, src, slen);
return 0;
}
memset(&strm, 0, sizeof(strm));
strm.workspace = kvzalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
if (!strm.workspace)
return -ENOMEM;
strm.next_in = src;
strm.avail_in = slen;
error = zlib_inflateInit(&strm);
if (error != Z_OK) {
error = -ENOMEM;
goto fail_inflate_init;
}
strm.next_out = dst;
strm.avail_out = dlen;
error = zlib_inflate(&strm, Z_FINISH);
if (error != Z_STREAM_END)
error = -EINVAL;
else
error = 0;
zlib_inflateEnd(&strm);
fail_inflate_init:
kvfree(strm.workspace);
return error;
}
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 (!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 = deflate_decompress(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("sha1", 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);
}
/** 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])
new->dents[i]->d_inode->i_mtime = current_time(new->dents[i]->d_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;
}
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 void rawdata_link_cb(void *arg)
{
kfree(arg);
}
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, rawdata_link_cb, target);
return target;
}
static const char *rawdata_get_link_sha1(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
return rawdata_get_link_base(dentry, inode, done, "sha1");
}
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_sha1_iops = {
.get_link = rawdata_get_link_sha1,
};
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,
};
/*
* 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);
/* 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, "sha1", profile,
&seq_profile_hash_fops);
if (IS_ERR(dent))
goto fail;
profile->dents[AAFS_PROF_HASH] = dent;
}
if (profile->rawdata) {
dent = aafs_create_symlink("raw_sha1", dir, NULL,
profile->label.proxy,
&rawdata_link_sha1_iops);
if (IS_ERR(dent))
goto fail;
aa_get_proxy(profile->label.proxy);
profile->dents[AAFS_PROF_RAW_HASH] = dent;
dent = aafs_create_symlink("raw_abi", dir, NULL,
profile->label.proxy,
&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_symlink("raw_data", dir, NULL,
profile->label.proxy,
&rawdata_link_data_iops);
if (IS_ERR(dent))
goto fail;
aa_get_proxy(profile->label.proxy);
profile->dents[AAFS_PROF_RAW_DATA] = dent;
}
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 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(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(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;
}
#define list_entry_is_head(pos, head, member) (&pos->member == (head))
/**
* __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
* @profile: 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 (!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_STRING("version", "1.2"),
{ }
};
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),
{ }
};
static struct aa_sfs_entry aa_sfs_entry_policy[] = {
AA_SFS_DIR("versions", aa_sfs_entry_versions),
AA_SFS_FILE_BOOLEAN("set_load", 1),
{ }
};
static struct aa_sfs_entry aa_sfs_entry_mount[] = {
AA_SFS_FILE_STRING("mask", "mount umount pivot_root"),
{ }
};
static struct aa_sfs_entry aa_sfs_entry_ns[] = {
AA_SFS_FILE_BOOLEAN("profile", 1),
AA_SFS_FILE_BOOLEAN("pivot_root", 0),
{ }
};
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_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),
{ }
};
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_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;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(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);