openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity
linux/security/apparmor/apparmorfs.c

2494 lines
60 KiB
C
Raw Blame History

/*
* AppArmor security module
*
* This file contains AppArmor /sys/kernel/security/apparmor interface functions
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*/
#include <linux/ctype.h>
#include <linux/security.h>
#include <linux/vmalloc.h>
#include <linux/module.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/poll.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/context.h"
#include "include/crypto.h"
#include "include/policy_ns.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
*/
/**
* 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)
{
struct inode *inode = d_inode(dentry);
seq_printf(seq, "%s:[%lu]", AAFS_NAME, inode->i_ino);
return 0;
}
static void aafs_evict_inode(struct inode *inode)
{
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
if (S_ISLNK(inode->i_mode))
kfree(inode->i_link);
}
static const struct super_operations aafs_super_ops = {
.statfs = simple_statfs,
.evict_inode = aafs_evict_inode,
.show_path = aafs_show_path,
};
static int fill_super(struct super_block *sb, void *data, int silent)
{
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 struct dentry *aafs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_single(fs_type, flags, data, fill_super);
}
static struct file_system_type aafs_ops = {
.owner = THIS_MODULE,
.name = AAFS_NAME,
.mount = aafs_mount,
.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))
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
* @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,
const struct inode_operations *iops)
{
struct dentry *dent;
char *link = NULL;
if (target) {
link = kstrdup(target, GFP_KERNEL);
if (!link)
return ERR_PTR(-ENOMEM);
}
dent = aafs_create(name, S_IFLNK | 0444, parent, NULL, 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);
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(&rev->ns->lock);
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(&rev->ns->lock);
}
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 unsigned int ns_revision_poll(struct file *file, poll_table *pt)
{
struct aa_revision *rev = file->private_data;
unsigned int mask = 0;
if (rev) {
mutex_lock(&rev->ns->lock);
poll_wait(file, &rev->ns->wait, pt);
if (rev->last_read < rev->ns->revision)
mask |= POLLIN | POLLRDNORM;
mutex_unlock(&rev->ns->lock);
}
return mask;
}
void __aa_bump_ns_revision(struct aa_ns *ns)
{
ns->revision++;
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);
tmp = nullperms;
if (state) {
struct path_cond cond = { };
tmp = aa_compute_fperms(dfa, state, &cond);
}
} else if (profile->policy.dfa) {
if (!PROFILE_MEDIATES_SAFE(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);
else
tmp = nullperms;
}
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", aa_ns_name(labels_ns(label),
labels_ns(label), true));
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;
}
SEQ_RAWDATA_FOPS(abi);
SEQ_RAWDATA_FOPS(revision);
SEQ_RAWDATA_FOPS(hash);
static ssize_t rawdata_read(struct file *file, char __user *buf, size_t size,
loff_t *ppos)
{
struct aa_loaddata *rawdata = file->private_data;
return simple_read_from_buffer(buf, size, ppos, rawdata->data,
rawdata->size);
}
static int rawdata_release(struct inode *inode, struct file *file)
{
aa_put_loaddata(file->private_data);
return 0;
}
static int rawdata_open(struct inode *inode, struct file *file)
{
if (!policy_view_capable(NULL))
return -EACCES;
file->private_data = __aa_get_loaddata(inode->i_private);
if (!file->private_data)
/* lost race: this entry is being reaped */
return -ENOENT;
return 0;
}
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("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;
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 int gen_symlink_name(char *buffer, size_t bsize, int depth,
const char *dirname, const char *fname)
{
int error;
for (; depth > 0; depth--) {
if (bsize < 7)
return -ENAMETOOLONG;
strcpy(buffer, "../../");
buffer += 6;
bsize -= 6;
}
error = snprintf(buffer, bsize, "raw_data/%s/%s", dirname, fname);
if (error >= bsize || error < 0)
return -ENAMETOOLONG;
return 0;
}
/*
* 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;
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) {
char target[64];
int depth = profile_depth(profile);
error = gen_symlink_name(target, sizeof(target), depth,
profile->rawdata->name, "sha1");
if (error < 0)
goto fail2;
dent = aafs_create_symlink("raw_sha1", dir, target, NULL);
if (IS_ERR(dent))
goto fail;
profile->dents[AAFS_PROF_RAW_HASH] = dent;
error = gen_symlink_name(target, sizeof(target), depth,
profile->rawdata->name, "abi");
if (error < 0)
goto fail2;
dent = aafs_create_symlink("raw_abi", dir, target, NULL);
if (IS_ERR(dent))
goto fail;
profile->dents[AAFS_PROF_RAW_ABI] = dent;
error = gen_symlink_name(target, sizeof(target), depth,
profile->rawdata->name, "raw_data");
if (error < 0)
goto fail2;
dent = aafs_create_symlink("raw_data", dir, target, NULL);
if (IS_ERR(dent))
goto fail;
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(&parent->lock);
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(&parent->lock);
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;
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(&sub->lock);
__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(&sub->lock);
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;
/* is next namespace a child */
if (!list_empty(&ns->sub_ns)) {
next = list_first_entry(&ns->sub_ns, typeof(*ns), base.list);
mutex_lock(&next->lock);
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(&next->lock);
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)
{
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;
/* 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(&root->lock);
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_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_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),
{ }
};
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_ns[] = {
AA_SFS_FILE_BOOLEAN("profile", 1),
AA_SFS_FILE_BOOLEAN("pivot_root", 1),
{ }
};
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("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("query", aa_sfs_entry_query),
{ }
};
static struct aa_sfs_entry aa_sfs_entry_apparmor[] = {
AA_SFS_FILE_FOPS(".access", 0640, &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", 0666, &seq_ns_level_fops),
AA_SFS_FILE_FOPS(".ns_name", 0640, &seq_ns_name_fops),
AA_SFS_FILE_FOPS("profiles", 0440, &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;
if (!dentry)
return ERR_PTR(-ECHILD);
ns = aa_get_current_ns();
path.mnt = mntget(aafs_mnt);
path.dentry = dget(ns_dir(ns));
nd_jump_link(&path);
aa_put_ns(ns);
return NULL;
}
static int ns_get_name(char *buf, size_t size, struct aa_ns *ns,
struct inode *inode)
{
int res = snprintf(buf, size, "%s:[%lu]", AAFS_NAME, inode->i_ino);
if (res < 0 || res >= size)
res = -ENOENT;
return res;
}
static int policy_readlink(struct dentry *dentry, char __user *buffer,
int buflen)
{
struct aa_ns *ns;
char name[32];
int res;
ns = aa_get_current_ns();
res = ns_get_name(name, sizeof(name), ns, d_inode(dentry));
if (res >= 0)
res = readlink_copy(buffer, buflen, name);
aa_put_ns(ns);
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 &= ~MS_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)) {
error = PTR_ERR(dent);
goto 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)) {
error = PTR_ERR(dent);
goto 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)) {
error = PTR_ERR(dent);
goto 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)) {
error = PTR_ERR(dent);
goto error;
}
ns_subrevision(root_ns) = dent;
/* policy tree referenced by magic policy symlink */
mutex_lock(&root_ns->lock);
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)) {
error = PTR_ERR(dent);
goto 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;
error:
aa_destroy_aafs();
AA_ERROR("Error creating AppArmor securityfs\n");
return error;
}
fs_initcall(aa_create_aafs);
Reference in New Issue View Git Blame Copy Permalink