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b873498f99
Add a simple helper to chown with a kernel space file name and switch the early init code over to it. Signed-off-by: Christoph Hellwig <hch@lst.de>
107 lines
2.5 KiB
C
107 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Routines that mimic syscalls, but don't use the user address space or file
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* descriptors. Only for init/ and related early init code.
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*/
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#include <linux/init.h>
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#include <linux/mount.h>
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#include <linux/namei.h>
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#include <linux/fs.h>
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#include <linux/fs_struct.h>
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#include <linux/init_syscalls.h>
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#include <linux/security.h>
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#include "internal.h"
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int __init init_mount(const char *dev_name, const char *dir_name,
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const char *type_page, unsigned long flags, void *data_page)
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{
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struct path path;
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int ret;
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ret = kern_path(dir_name, LOOKUP_FOLLOW, &path);
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if (ret)
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return ret;
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ret = path_mount(dev_name, &path, type_page, flags, data_page);
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path_put(&path);
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return ret;
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}
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int __init init_umount(const char *name, int flags)
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{
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int lookup_flags = LOOKUP_MOUNTPOINT;
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struct path path;
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int ret;
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if (!(flags & UMOUNT_NOFOLLOW))
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lookup_flags |= LOOKUP_FOLLOW;
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ret = kern_path(name, lookup_flags, &path);
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if (ret)
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return ret;
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return path_umount(&path, flags);
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}
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int __init init_chdir(const char *filename)
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{
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struct path path;
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int error;
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error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
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if (error)
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return error;
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error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
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if (!error)
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set_fs_pwd(current->fs, &path);
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path_put(&path);
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return error;
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}
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int __init init_chroot(const char *filename)
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{
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struct path path;
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int error;
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error = kern_path(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
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if (error)
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return error;
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error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
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if (error)
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goto dput_and_out;
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error = -EPERM;
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if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
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goto dput_and_out;
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error = security_path_chroot(&path);
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if (error)
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goto dput_and_out;
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set_fs_root(current->fs, &path);
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dput_and_out:
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path_put(&path);
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return error;
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}
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int __init init_chown(const char *filename, uid_t user, gid_t group, int flags)
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{
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int lookup_flags = (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
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struct path path;
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int error;
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error = kern_path(filename, lookup_flags, &path);
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if (error)
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return error;
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error = mnt_want_write(path.mnt);
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if (!error) {
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error = chown_common(&path, user, group);
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mnt_drop_write(path.mnt);
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}
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path_put(&path);
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return error;
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}
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int __init init_unlink(const char *pathname)
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{
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return do_unlinkat(AT_FDCWD, getname_kernel(pathname));
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}
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int __init init_rmdir(const char *pathname)
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{
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return do_rmdir(AT_FDCWD, getname_kernel(pathname));
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}
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