SYSCALL_DEFINE1(chroot, const char __user *, filename)
{
struct path path;
int error;
error = user_path_dir(filename, &path);
if (error)
goto out;
error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
error = -EPERM;
if (!capable(CAP_SYS_CHROOT))
goto dput_and_out;
error = security_path_chroot(&path);
if (error)
goto dput_and_out;
set_fs_root(current->fs, &path);
error = 0;
dput_and_out:
path_put(&path);
out:
return error;
}
asmlinkage long sys_chroot(const char __user * filename)
{
struct nameidata nd;
struct fs_struct *fs;
int error;
error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
if (error)
goto out;
error = vfs_permission(d_get_inode_ro(nd.dentry), &nd, MAY_EXEC);
if (error)
goto dput_and_out;
error = -EPERM;
if (!capable(CAP_SYS_CHROOT))
goto dput_and_out;
fs = tx_cache_get_fs(current);
set_fs_root(fs, nd.mnt, parent(nd.dentry));
set_fs_altroot();
error = 0;
dput_and_out:
path_release(&nd);
out:
return error;
}
SYSCALL_DEFINE1(chroot, const char __user *, filename)
{
struct path path;
int error;
error = user_path_dir(filename, &path);
if (error)
goto out;
error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
if (error)
goto dput_and_out;
error = -EPERM;
if (!capable(CAP_SYS_CHROOT))
goto dput_and_out;
if (gr_handle_chroot_chroot(path.dentry, path.mnt))
goto dput_and_out;
if (gr_handle_chroot_caps(&path)) {
error = -ENOMEM;
goto dput_and_out;
}
set_fs_root(current->fs, &path);
gr_handle_chroot_chdir(&path);
error = 0;
dput_and_out:
path_put(&path);
out:
return error;
}
asmlinkage long sys_chroot(const char * filename)
{
int error;
struct nameidata nd;
char *name;
name = getname(filename);
error = PTR_ERR(name);
if (IS_ERR(name))
goto out;
path_init(name, LOOKUP_POSITIVE | LOOKUP_FOLLOW |
LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
error = path_walk(name, &nd);
putname(name);
if (error)
goto out;
error = permission(nd.dentry->d_inode,MAY_EXEC);
if (error)
goto dput_and_out;
error = -EPERM;
if (!capable(CAP_SYS_CHROOT))
goto dput_and_out;
set_fs_root(current->fs, nd.mnt, nd.dentry);
set_fs_altroot();
error = 0;
dput_and_out:
path_release(&nd);
out:
return error;
}
SYSCALL_DEFINE1(chroot, const char __user *, filename)
{
struct path path;
int error;
unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
retry:
error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
if (error)
goto out;
error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
if (error)
goto dput_and_out;
error = -EPERM;
if (!nsown_capable(CAP_SYS_CHROOT))
goto dput_and_out;
error = security_path_chroot(&path);
if (error)
goto dput_and_out;
set_fs_root(current->fs, &path);
error = 0;
dput_and_out:
path_put(&path);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
out:
return error;
}
asmlinkage long sys_chroot(const char __user * filename)
{
struct nameidata nd;
int error;
error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd);
if (error)
goto out;
error = permission(nd.dentry->d_inode,MAY_EXEC,&nd);
if (error)
goto dput_and_out;
error = -EPERM;
if (!capable(CAP_SYS_CHROOT))
goto dput_and_out;
set_fs_root(current->fs, nd.mnt, nd.dentry);
set_fs_altroot();
error = 0;
dput_and_out:
path_release(&nd);
out:
return error;
}
/**
* Change current's root to configfs scheduler subsystem'root, and save
* previous root in parameters.
*
* @param prev_root valid pointer to a struct path
*
* @return prev_rootmnt and prev_root are filled with the previous
* root. They must be restored with chroot_restore, or
* mntput/dput when not needed anymore.
*/
static void chroot_to_scheduler_subsystem(struct path *prev_root)
{
struct path new_root;
/*
* These two values won't change unless a pivot_root is running ...
* but we assume that this can not happen.
* Locking is more used for memory barriers than for anything else.
*/
read_lock(¤t->fs->lock);
*prev_root = current->fs->root;
path_get(prev_root);
read_unlock(¤t->fs->lock);
new_root.mnt = scheduler_fs_mount;
new_root.dentry = krg_scheduler_subsys.su_group.cg_item.ci_dentry;
set_fs_root(current->fs, &new_root);
}
asmlinkage long sys_chroot(const char __user * filename)
{
struct path path;
int error;
error = user_path_dir(filename, &path);
if (error)
goto out;
error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
if (error)
goto dput_and_out;
error = -EPERM;
if (!capable(CAP_SYS_CHROOT))
goto dput_and_out;
set_fs_root(current->fs, &path);
error = 0;
dput_and_out:
path_put(&path);
out:
return error;
}
/*
* Allocates utab entry (upd->fs) for mount/remount. This function should be
* called *before* mount(2) syscall. The @fs is used as a read-only template.
*
* Returns: 0 on success, negative number on error, 1 if utabs update is
* unnecessary.
*/
static int utab_new_entry(struct libmnt_update *upd, struct libmnt_fs *fs,
unsigned long mountflags)
{
int rc = 0;
const char *o = NULL, *a = NULL;
char *u = NULL;
assert(fs);
assert(upd);
assert(upd->fs == NULL);
assert(!(mountflags & MS_MOVE));
DBG(UPDATE, mnt_debug("prepare utab entry"));
o = mnt_fs_get_user_options(fs);
a = mnt_fs_get_attributes(fs);
upd->fs = NULL;
if (o) {
/* remove non-mtab options */
rc = mnt_optstr_get_options(o, &u,
mnt_get_builtin_optmap(MNT_USERSPACE_MAP),
MNT_NOMTAB);
if (rc)
goto err;
}
if (!u && !a) {
DBG(UPDATE, mnt_debug("utab entry unnecessary (no options)"));
return 1;
}
/* allocate the entry */
upd->fs = mnt_copy_fs(NULL, fs);
if (!upd->fs) {
rc = -ENOMEM;
goto err;
}
rc = mnt_fs_set_options(upd->fs, u);
if (rc)
goto err;
rc = mnt_fs_set_attributes(upd->fs, a);
if (rc)
goto err;
if (!(mountflags & MS_REMOUNT)) {
rc = set_fs_root(upd, fs, mountflags);
if (rc)
goto err;
}
free(u);
DBG(UPDATE, mnt_debug("utab entry OK"));
return 0;
err:
free(u);
mnt_free_fs(upd->fs);
upd->fs = NULL;
return rc;
}
static void chroot_restore(struct path *prev_root)
{
set_fs_root(current->fs, prev_root);
path_put(prev_root);
}
