/* * 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/security.h> #include <linux/vmalloc.h> #include <linux/module.h> #include <linux/seq_file.h> #include <linux/uaccess.h> #include <linux/namei.h> #include <linux/capability.h> #include "include/apparmor.h" #include "include/apparmorfs.h" #include "include/audit.h" #include "include/context.h" #include "include/policy.h" #include "include/resource.h" /** * aa_simple_write_to_buffer - common routine for getting policy from user * @op: operation doing the user buffer copy * @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 char *aa_simple_write_to_buffer(int op, const char __user *userbuf, size_t alloc_size, size_t copy_size, loff_t *pos) { char *data; BUG_ON(copy_size > alloc_size); if (*pos != 0) /* only writes from pos 0, that is complete writes */ return ERR_PTR(-ESPIPE); /* * Don't allow profile load/replace/remove from profiles that don't * have CAP_MAC_ADMIN */ if (!aa_may_manage_policy(op)) return ERR_PTR(-EACCES); /* freed by caller to simple_write_to_buffer */ data = kvmalloc(alloc_size); if (data == NULL) return ERR_PTR(-ENOMEM); if (copy_from_user(data, userbuf, copy_size)) { kvfree(data); return ERR_PTR(-EFAULT); } return data; } /* .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) { char *data; ssize_t error; data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos); error = PTR_ERR(data); if (!IS_ERR(data)) { error = aa_replace_profiles(data, size, PROF_ADD); kvfree(data); } 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) { char *data; ssize_t error; data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos); error = PTR_ERR(data); if (!IS_ERR(data)) { error = aa_replace_profiles(data, size, PROF_REPLACE); kvfree(data); } 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) { char *data; ssize_t error; /* * 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(OP_PROF_RM, buf, size + 1, size, pos); error = PTR_ERR(data); if (!IS_ERR(data)) { data[size] = 0; error = aa_remove_profiles(data, size); kvfree(data); } return error; } static const struct file_operations aa_fs_profile_remove = { .write = profile_remove, .llseek = default_llseek, }; static int aa_fs_seq_show(struct seq_file *seq, void *v) { struct aa_fs_entry *fs_file = seq->private; if (!fs_file) return 0; switch (fs_file->v_type) { case AA_FS_TYPE_BOOLEAN: seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no"); break; case AA_FS_TYPE_STRING: seq_printf(seq, "%s\n", fs_file->v.string); break; case AA_FS_TYPE_U64: seq_printf(seq, "%#08lx\n", fs_file->v.u64); break; default: /* Ignore unpritable entry types. */ break; } return 0; } static int aa_fs_seq_open(struct inode *inode, struct file *file) { return single_open(file, aa_fs_seq_show, inode->i_private); } const struct file_operations aa_fs_seq_file_ops = { .owner = THIS_MODULE, .open = aa_fs_seq_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; /** Base file system setup **/ static struct aa_fs_entry aa_fs_entry_file[] = { AA_FS_FILE_STRING("mask", "create read write exec append mmap_exec " \ "link lock"), { } }; static struct aa_fs_entry aa_fs_entry_domain[] = { AA_FS_FILE_BOOLEAN("change_hat", 1), AA_FS_FILE_BOOLEAN("change_hatv", 1), AA_FS_FILE_BOOLEAN("change_onexec", 1), AA_FS_FILE_BOOLEAN("change_profile", 1), { } }; static struct aa_fs_entry aa_fs_entry_features[] = { AA_FS_DIR("domain", aa_fs_entry_domain), AA_FS_DIR("file", aa_fs_entry_file), AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK), AA_FS_DIR("rlimit", aa_fs_entry_rlimit), { } }; static struct aa_fs_entry aa_fs_entry_apparmor[] = { AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load), AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace), AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove), AA_FS_DIR("features", aa_fs_entry_features), { } }; static struct aa_fs_entry aa_fs_entry = AA_FS_DIR("apparmor", aa_fs_entry_apparmor); /** * aafs_create_file - create a file entry in the apparmor securityfs * @fs_file: aa_fs_entry to build an entry for (NOT NULL) * @parent: the parent dentry in the securityfs * * Use aafs_remove_file to remove entries created with this fn. */ static int __init aafs_create_file(struct aa_fs_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; } /** * aafs_create_dir - recursively create a directory entry in the securityfs * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL) * @parent: the parent dentry in the securityfs * * Use aafs_remove_dir to remove entries created with this fn. */ static int __init aafs_create_dir(struct aa_fs_entry *fs_dir, struct dentry *parent) { int error; struct aa_fs_entry *fs_file; fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent); if (IS_ERR(fs_dir->dentry)) { error = PTR_ERR(fs_dir->dentry); fs_dir->dentry = NULL; goto failed; } for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) { if (fs_file->v_type == AA_FS_TYPE_DIR) error = aafs_create_dir(fs_file, fs_dir->dentry); else error = aafs_create_file(fs_file, fs_dir->dentry); if (error) goto failed; } return 0; failed: return error; } /** * aafs_remove_file - drop a single file entry in the apparmor securityfs * @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL) */ static void __init aafs_remove_file(struct aa_fs_entry *fs_file) { if (!fs_file->dentry) return; securityfs_remove(fs_file->dentry); fs_file->dentry = NULL; } /** * aafs_remove_dir - recursively drop a directory entry from the securityfs * @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL) */ static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir) { struct aa_fs_entry *fs_file; for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) { if (fs_file->v_type == AA_FS_TYPE_DIR) aafs_remove_dir(fs_file); else aafs_remove_file(fs_file); } aafs_remove_file(fs_dir); } /** * aa_destroy_aafs - cleanup and free aafs * * releases dentries allocated by aa_create_aafs */ void __init aa_destroy_aafs(void) { aafs_remove_dir(&aa_fs_entry); } /** * 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) { int error; if (!apparmor_initialized) return 0; if (aa_fs_entry.dentry) { AA_ERROR("%s: AppArmor securityfs already exists\n", __func__); return -EEXIST; } /* Populate fs tree. */ error = aafs_create_dir(&aa_fs_entry, NULL); if (error) goto error; /* TODO: add support for apparmorfs_null and apparmorfs_mnt */ /* 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);