int gr_is_outside_chroot(const struct dentry *u_dentry, const struct vfsmount *u_mnt)
{
struct path path, currentroot;
int ret = 0;
path.dentry = (struct dentry *)u_dentry;
path.mnt = (struct vfsmount *)u_mnt;
get_fs_root(current->fs, ¤troot);
if (path_is_under(&path, ¤troot))
ret = 1;
path_put(¤troot);
return ret;
}
/**
* d_namespace_path - lookup a name associated with a given path
* @path: path to lookup (NOT NULL)
* @buf: buffer to store path to (NOT NULL)
* @buflen: length of @buf
* @name: Returns - pointer for start of path name with in @buf (NOT NULL)
* @flags: flags controlling path lookup
*
* Handle path name lookup.
*
* Returns: %0 else error code if path lookup fails
* When no error the path name is returned in @name which points to
* to a position in @buf
*/
static int d_namespace_path(struct path *path, char *buf, int buflen,
char **name, int flags)
{
struct path root, tmp;
char *res;
int connected, error = 0;
/* Get the root we want to resolve too, released below */
if (flags & PATH_CHROOT_REL) {
/* resolve paths relative to chroot */
get_fs_root(current->fs, &root);
} else {
/* resolve paths relative to namespace */
root.mnt = current->nsproxy->mnt_ns->root;
root.dentry = root.mnt->mnt_root;
path_get(&root);
}
tmp = root;
res = __d_path(path, &tmp, buf, buflen);
*name = res;
/* handle error conditions - and still allow a partial path to
* be returned.
*/
if (IS_ERR(res)) {
error = PTR_ERR(res);
*name = buf;
goto out;
}
/* Handle two cases:
* 1. A deleted dentry && profile is not allowing mediation of deleted
* 2. On some filesystems, newly allocated dentries appear to the
* security_path hooks as a deleted dentry except without an inode
* allocated.
*/
if (d_unlinked(path->dentry) && path->dentry->d_inode &&
!(flags & PATH_MEDIATE_DELETED)) {
error = -ENOENT;
goto out;
}
/* Determine if the path is connected to the expected root */
connected = tmp.dentry == root.dentry && tmp.mnt == root.mnt;
/* If the path is not connected,
* check if it is a sysctl and handle specially else remove any
* leading / that __d_path may have returned.
* Unless
* specifically directed to connect the path,
* OR
* if in a chroot and doing chroot relative paths and the path
* resolves to the namespace root (would be connected outside
* of chroot) and specifically directed to connect paths to
* namespace root.
*/
if (!connected) {
/* is the disconnect path a sysctl? */
if (tmp.dentry->d_sb->s_magic == PROC_SUPER_MAGIC &&
strncmp(*name, "/sys/", 5) == 0) {
/* TODO: convert over to using a per namespace
* control instead of hard coded /proc
*/
error = prepend(name, *name - buf, "/proc", 5);
} else if (!(flags & PATH_CONNECT_PATH) &&
!(((flags & CHROOT_NSCONNECT) == CHROOT_NSCONNECT) &&
(tmp.mnt == current->nsproxy->mnt_ns->root &&
tmp.dentry == tmp.mnt->mnt_root))) {
/* disconnected path, don't return pathname starting
* with '/'
*/
error = -ESTALE;
if (*res == '/')
*name = res + 1;
}
}
out:
path_put(&root);
return error;
}
/**
* d_namespace_path - lookup a name associated with a given path
* @path: path to lookup (NOT NULL)
* @buf: buffer to store path to (NOT NULL)
* @buflen: length of @buf
* @name: Returns - pointer for start of path name with in @buf (NOT NULL)
* @flags: flags controlling path lookup
*
* Handle path name lookup.
*
* Returns: %0 else error code if path lookup fails
* When no error the path name is returned in @name which points to
* to a position in @buf
*/
static int d_namespace_path(struct path *path, char *buf, int buflen,
char **name, int flags)
{
char *res;
int error = 0;
int connected = 1;
if (path->mnt->mnt_flags & MNT_INTERNAL) {
/* it's not mounted anywhere */
res = dentry_path(path->dentry, buf, buflen);
*name = res;
if (IS_ERR(res)) {
*name = buf;
return PTR_ERR(res);
}
if (path->dentry->d_sb->s_magic == PROC_SUPER_MAGIC &&
strncmp(*name, "/sys/", 5) == 0) {
/* TODO: convert over to using a per namespace
* control instead of hard coded /proc
*/
return prepend(name, *name - buf, "/proc", 5);
}
return 0;
}
/* resolve paths relative to chroot?*/
if (flags & PATH_CHROOT_REL) {
struct path root;
get_fs_root(current->fs, &root);
res = __d_path(path, &root, buf, buflen);
path_put(&root);
} else {
res = d_absolute_path(path, buf, buflen);
if (!our_mnt(path->mnt))
connected = 0;
}
/* handle error conditions - and still allow a partial path to
* be returned.
*/
if (!res || IS_ERR(res)) {
connected = 0;
res = dentry_path_raw(path->dentry, buf, buflen);
if (IS_ERR(res)) {
error = PTR_ERR(res);
*name = buf;
goto out;
};
} else if (!our_mnt(path->mnt))
connected = 0;
*name = res;
/* Handle two cases:
* 1. A deleted dentry && profile is not allowing mediation of deleted
* 2. On some filesystems, newly allocated dentries appear to the
* security_path hooks as a deleted dentry except without an inode
* allocated.
*/
if (d_unlinked(path->dentry) && path->dentry->d_inode &&
!(flags & PATH_MEDIATE_DELETED)) {
error = -ENOENT;
goto out;
}
/* If the path is not connected to the expected root,
* check if it is a sysctl and handle specially else remove any
* leading / that __d_path may have returned.
* Unless
* specifically directed to connect the path,
* OR
* if in a chroot and doing chroot relative paths and the path
* resolves to the namespace root (would be connected outside
* of chroot) and specifically directed to connect paths to
* namespace root.
*/
if (!connected) {
if (!(flags & PATH_CONNECT_PATH) &&
!(((flags & CHROOT_NSCONNECT) == CHROOT_NSCONNECT) &&
our_mnt(path->mnt))) {
/* disconnected path, don't return pathname starting
* with '/'
*/
error = -ESTALE;
if (*res == '/')
*name = res + 1;
}
}
out:
return error;
}
static int show_vfsmnt(struct seq_file *m, struct vfsmount *mnt)
{
struct mount *r = real_mount(mnt);
int err = 0;
struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
struct super_block *sb = mnt_path.dentry->d_sb;
if (sb->s_op->show_devname) {
err = sb->s_op->show_devname(m, mnt_path.dentry);
if (err)
goto out;
} else {
mangle(m, r->mnt_devname ? r->mnt_devname : "none");
}
seq_putc(m, ' ');
seq_path(m, &mnt_path, " \t\n\\");
seq_putc(m, ' ');
show_type(m, sb);
seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
err = show_sb_opts(m, sb);
if (err)
goto out;
show_mnt_opts(m, mnt);
if (sb->s_op->show_options)
err = sb->s_op->show_options(m, mnt_path.dentry);
seq_puts(m, " 0 0\n");
out:
return err;
}
static int show_mountinfo(struct seq_file *m, struct vfsmount *mnt)
{
struct proc_mounts *p = proc_mounts(m);
struct mount *r = real_mount(mnt);
struct super_block *sb = mnt->mnt_sb;
struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
struct path root = p->root;
int err = 0;
seq_printf(m, "%i %i %u:%u ", r->mnt_id, r->mnt_parent->mnt_id,
MAJOR(sb->s_dev), MINOR(sb->s_dev));
if (sb->s_op->show_path)
err = sb->s_op->show_path(m, mnt->mnt_root);
else
seq_dentry(m, mnt->mnt_root, " \t\n\\");
if (err)
goto out;
seq_putc(m, ' ');
/* mountpoints outside of chroot jail will give SEQ_SKIP on this */
err = seq_path_root(m, &mnt_path, &root, " \t\n\\");
if (err)
goto out;
seq_puts(m, mnt->mnt_flags & MNT_READONLY ? " ro" : " rw");
show_mnt_opts(m, mnt);
/* Tagged fields ("foo:X" or "bar") */
if (IS_MNT_SHARED(r))
seq_printf(m, " shared:%i", r->mnt_group_id);
if (IS_MNT_SLAVE(r)) {
int master = r->mnt_master->mnt_group_id;
int dom = get_dominating_id(r, &p->root);
seq_printf(m, " master:%i", master);
if (dom && dom != master)
seq_printf(m, " propagate_from:%i", dom);
}
if (IS_MNT_UNBINDABLE(r))
seq_puts(m, " unbindable");
/* Filesystem specific data */
seq_puts(m, " - ");
show_type(m, sb);
seq_putc(m, ' ');
if (sb->s_op->show_devname)
err = sb->s_op->show_devname(m, mnt->mnt_root);
else
mangle(m, r->mnt_devname ? r->mnt_devname : "none");
if (err)
goto out;
seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
err = show_sb_opts(m, sb);
if (err)
goto out;
if (sb->s_op->show_options)
err = sb->s_op->show_options(m, mnt->mnt_root);
seq_putc(m, '\n');
out:
return err;
}
static int show_vfsstat(struct seq_file *m, struct vfsmount *mnt)
{
struct mount *r = real_mount(mnt);
struct path mnt_path = { .dentry = mnt->mnt_root, .mnt = mnt };
struct super_block *sb = mnt_path.dentry->d_sb;
int err = 0;
/* device */
if (sb->s_op->show_devname) {
seq_puts(m, "device ");
err = sb->s_op->show_devname(m, mnt_path.dentry);
} else {
if (r->mnt_devname) {
seq_puts(m, "device ");
mangle(m, r->mnt_devname);
} else
seq_puts(m, "no device");
}
/* mount point */
seq_puts(m, " mounted on ");
seq_path(m, &mnt_path, " \t\n\\");
seq_putc(m, ' ');
/* file system type */
seq_puts(m, "with fstype ");
show_type(m, sb);
/* optional statistics */
if (sb->s_op->show_stats) {
seq_putc(m, ' ');
if (!err)
err = sb->s_op->show_stats(m, mnt_path.dentry);
}
seq_putc(m, '\n');
return err;
}
static int mounts_open_common(struct inode *inode, struct file *file,
int (*show)(struct seq_file *, struct vfsmount *))
{
struct task_struct *task = get_proc_task(inode);
struct nsproxy *nsp;
struct mnt_namespace *ns = NULL;
struct path root;
struct proc_mounts *p;
int ret = -EINVAL;
if (!task)
goto err;
task_lock(task);
nsp = task->nsproxy;
if (!nsp || !nsp->mnt_ns) {
task_unlock(task);
put_task_struct(task);
goto err;
}
ns = nsp->mnt_ns;
get_mnt_ns(ns);
if (!task->fs) {
task_unlock(task);
put_task_struct(task);
ret = -ENOENT;
goto err_put_ns;
}
get_fs_root(task->fs, &root);
task_unlock(task);
put_task_struct(task);
ret = -ENOMEM;
p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
if (!p)
goto err_put_path;
file->private_data = &p->m;
ret = seq_open(file, &mounts_op);
if (ret)
goto err_free;
p->ns = ns;
p->root = root;
p->m.poll_event = ns->event;
p->show = show;
return 0;
err_free:
kfree(p);
err_put_path:
path_put(&root);
err_put_ns:
put_mnt_ns(ns);
err:
return ret;
}
static int mounts_release(struct inode *inode, struct file *file)
{
struct proc_mounts *p = proc_mounts(file->private_data);
path_put(&p->root);
put_mnt_ns(p->ns);
return seq_release(inode, file);
}
static int mounts_open(struct inode *inode, struct file *file)
{
return mounts_open_common(inode, file, show_vfsmnt);
}
static int mountinfo_open(struct inode *inode, struct file *file)
{
return mounts_open_common(inode, file, show_mountinfo);
}
static int mountstats_open(struct inode *inode, struct file *file)
{
return mounts_open_common(inode, file, show_vfsstat);
}
const struct file_operations proc_mounts_operations = {
.open = mounts_open,
.read = seq_read,
.llseek = seq_lseek,
.release = mounts_release,
.poll = mounts_poll,
};
const struct file_operations proc_mountinfo_operations = {
.open = mountinfo_open,
.read = seq_read,
.llseek = seq_lseek,
.release = mounts_release,
.poll = mounts_poll,
};
const struct file_operations proc_mountstats_operations = {
.open = mountstats_open,
.read = seq_read,
.llseek = seq_lseek,
.release = mounts_release,
};
