f4941d75b9
As a prerequisite to adjusting LSM selection logic in the future, this moves the selection logic up out of the individual major LSMs, making their init functions only run when actually enabled. This considers all LSMs enabled by default unless they specified an external "enable" variable. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
556 lines
15 KiB
C
556 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* security/tomoyo/tomoyo.c
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*
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* Copyright (C) 2005-2011 NTT DATA CORPORATION
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*/
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#include <linux/lsm_hooks.h>
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#include "common.h"
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/**
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* tomoyo_cred_alloc_blank - Target for security_cred_alloc_blank().
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*
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* @new: Pointer to "struct cred".
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* @gfp: Memory allocation flags.
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*
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* Returns 0.
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*/
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static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
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{
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new->security = NULL;
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return 0;
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}
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/**
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* tomoyo_cred_prepare - Target for security_prepare_creds().
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*
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* @new: Pointer to "struct cred".
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* @old: Pointer to "struct cred".
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* @gfp: Memory allocation flags.
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*
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* Returns 0.
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*/
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static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
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gfp_t gfp)
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{
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struct tomoyo_domain_info *domain = old->security;
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new->security = domain;
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if (domain)
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atomic_inc(&domain->users);
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return 0;
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}
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/**
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* tomoyo_cred_transfer - Target for security_transfer_creds().
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*
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* @new: Pointer to "struct cred".
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* @old: Pointer to "struct cred".
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*/
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static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
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{
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tomoyo_cred_prepare(new, old, 0);
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}
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/**
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* tomoyo_cred_free - Target for security_cred_free().
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*
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* @cred: Pointer to "struct cred".
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*/
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static void tomoyo_cred_free(struct cred *cred)
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{
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struct tomoyo_domain_info *domain = cred->security;
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if (domain)
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atomic_dec(&domain->users);
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}
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/**
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* tomoyo_bprm_set_creds - Target for security_bprm_set_creds().
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*
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* @bprm: Pointer to "struct linux_binprm".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
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{
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/*
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* Do only if this function is called for the first time of an execve
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* operation.
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*/
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if (bprm->called_set_creds)
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return 0;
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#ifndef CONFIG_SECURITY_TOMOYO_OMIT_USERSPACE_LOADER
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/*
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* Load policy if /sbin/tomoyo-init exists and /sbin/init is requested
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* for the first time.
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*/
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if (!tomoyo_policy_loaded)
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tomoyo_load_policy(bprm->filename);
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#endif
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/*
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* Release reference to "struct tomoyo_domain_info" stored inside
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* "bprm->cred->security". New reference to "struct tomoyo_domain_info"
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* stored inside "bprm->cred->security" will be acquired later inside
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* tomoyo_find_next_domain().
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*/
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atomic_dec(&((struct tomoyo_domain_info *)
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bprm->cred->security)->users);
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/*
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* Tell tomoyo_bprm_check_security() is called for the first time of an
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* execve operation.
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*/
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bprm->cred->security = NULL;
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return 0;
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}
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/**
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* tomoyo_bprm_check_security - Target for security_bprm_check().
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*
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* @bprm: Pointer to "struct linux_binprm".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
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{
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struct tomoyo_domain_info *domain = bprm->cred->security;
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/*
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* Execute permission is checked against pathname passed to do_execve()
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* using current domain.
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*/
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if (!domain) {
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const int idx = tomoyo_read_lock();
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const int err = tomoyo_find_next_domain(bprm);
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tomoyo_read_unlock(idx);
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return err;
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}
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/*
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* Read permission is checked against interpreters using next domain.
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*/
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return tomoyo_check_open_permission(domain, &bprm->file->f_path,
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O_RDONLY);
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}
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/**
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* tomoyo_inode_getattr - Target for security_inode_getattr().
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*
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* @mnt: Pointer to "struct vfsmount".
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* @dentry: Pointer to "struct dentry".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_inode_getattr(const struct path *path)
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{
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return tomoyo_path_perm(TOMOYO_TYPE_GETATTR, path, NULL);
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}
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/**
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* tomoyo_path_truncate - Target for security_path_truncate().
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*
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* @path: Pointer to "struct path".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_truncate(const struct path *path)
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{
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return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path, NULL);
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}
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/**
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* tomoyo_path_unlink - Target for security_path_unlink().
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*
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* @parent: Pointer to "struct path".
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* @dentry: Pointer to "struct dentry".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_unlink(const struct path *parent, struct dentry *dentry)
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{
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struct path path = { .mnt = parent->mnt, .dentry = dentry };
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return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path, NULL);
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}
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/**
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* tomoyo_path_mkdir - Target for security_path_mkdir().
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*
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* @parent: Pointer to "struct path".
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* @dentry: Pointer to "struct dentry".
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* @mode: DAC permission mode.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_mkdir(const struct path *parent, struct dentry *dentry,
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umode_t mode)
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{
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struct path path = { .mnt = parent->mnt, .dentry = dentry };
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return tomoyo_path_number_perm(TOMOYO_TYPE_MKDIR, &path,
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mode & S_IALLUGO);
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}
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/**
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* tomoyo_path_rmdir - Target for security_path_rmdir().
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*
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* @parent: Pointer to "struct path".
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* @dentry: Pointer to "struct dentry".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_rmdir(const struct path *parent, struct dentry *dentry)
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{
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struct path path = { .mnt = parent->mnt, .dentry = dentry };
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return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path, NULL);
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}
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/**
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* tomoyo_path_symlink - Target for security_path_symlink().
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*
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* @parent: Pointer to "struct path".
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* @dentry: Pointer to "struct dentry".
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* @old_name: Symlink's content.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_symlink(const struct path *parent, struct dentry *dentry,
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const char *old_name)
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{
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struct path path = { .mnt = parent->mnt, .dentry = dentry };
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return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path, old_name);
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}
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/**
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* tomoyo_path_mknod - Target for security_path_mknod().
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*
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* @parent: Pointer to "struct path".
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* @dentry: Pointer to "struct dentry".
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* @mode: DAC permission mode.
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* @dev: Device attributes.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_mknod(const struct path *parent, struct dentry *dentry,
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umode_t mode, unsigned int dev)
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{
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struct path path = { .mnt = parent->mnt, .dentry = dentry };
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int type = TOMOYO_TYPE_CREATE;
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const unsigned int perm = mode & S_IALLUGO;
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switch (mode & S_IFMT) {
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case S_IFCHR:
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type = TOMOYO_TYPE_MKCHAR;
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break;
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case S_IFBLK:
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type = TOMOYO_TYPE_MKBLOCK;
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break;
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default:
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goto no_dev;
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}
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return tomoyo_mkdev_perm(type, &path, perm, dev);
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no_dev:
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switch (mode & S_IFMT) {
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case S_IFIFO:
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type = TOMOYO_TYPE_MKFIFO;
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break;
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case S_IFSOCK:
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type = TOMOYO_TYPE_MKSOCK;
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break;
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}
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return tomoyo_path_number_perm(type, &path, perm);
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}
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/**
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* tomoyo_path_link - Target for security_path_link().
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*
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* @old_dentry: Pointer to "struct dentry".
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* @new_dir: Pointer to "struct path".
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* @new_dentry: Pointer to "struct dentry".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_link(struct dentry *old_dentry, const struct path *new_dir,
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struct dentry *new_dentry)
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{
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struct path path1 = { .mnt = new_dir->mnt, .dentry = old_dentry };
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struct path path2 = { .mnt = new_dir->mnt, .dentry = new_dentry };
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return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
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}
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/**
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* tomoyo_path_rename - Target for security_path_rename().
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*
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* @old_parent: Pointer to "struct path".
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* @old_dentry: Pointer to "struct dentry".
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* @new_parent: Pointer to "struct path".
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* @new_dentry: Pointer to "struct dentry".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_rename(const struct path *old_parent,
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struct dentry *old_dentry,
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const struct path *new_parent,
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struct dentry *new_dentry)
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{
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struct path path1 = { .mnt = old_parent->mnt, .dentry = old_dentry };
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struct path path2 = { .mnt = new_parent->mnt, .dentry = new_dentry };
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return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
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}
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/**
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* tomoyo_file_fcntl - Target for security_file_fcntl().
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*
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* @file: Pointer to "struct file".
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* @cmd: Command for fcntl().
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* @arg: Argument for @cmd.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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if (!(cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND)))
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return 0;
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return tomoyo_check_open_permission(tomoyo_domain(), &file->f_path,
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O_WRONLY | (arg & O_APPEND));
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}
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/**
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* tomoyo_file_open - Target for security_file_open().
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*
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* @f: Pointer to "struct file".
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* @cred: Pointer to "struct cred".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_file_open(struct file *f)
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{
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int flags = f->f_flags;
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/* Don't check read permission here if called from do_execve(). */
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if (current->in_execve)
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return 0;
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return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
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}
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/**
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* tomoyo_file_ioctl - Target for security_file_ioctl().
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*
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* @file: Pointer to "struct file".
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* @cmd: Command for ioctl().
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* @arg: Argument for @cmd.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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return tomoyo_path_number_perm(TOMOYO_TYPE_IOCTL, &file->f_path, cmd);
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}
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/**
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* tomoyo_path_chmod - Target for security_path_chmod().
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*
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* @path: Pointer to "struct path".
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* @mode: DAC permission mode.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_chmod(const struct path *path, umode_t mode)
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{
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return tomoyo_path_number_perm(TOMOYO_TYPE_CHMOD, path,
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mode & S_IALLUGO);
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}
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/**
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* tomoyo_path_chown - Target for security_path_chown().
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*
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* @path: Pointer to "struct path".
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* @uid: Owner ID.
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* @gid: Group ID.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
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{
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int error = 0;
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if (uid_valid(uid))
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error = tomoyo_path_number_perm(TOMOYO_TYPE_CHOWN, path,
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from_kuid(&init_user_ns, uid));
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if (!error && gid_valid(gid))
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error = tomoyo_path_number_perm(TOMOYO_TYPE_CHGRP, path,
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from_kgid(&init_user_ns, gid));
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return error;
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}
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/**
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* tomoyo_path_chroot - Target for security_path_chroot().
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*
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* @path: Pointer to "struct path".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_path_chroot(const struct path *path)
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{
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return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path, NULL);
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}
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/**
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* tomoyo_sb_mount - Target for security_sb_mount().
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*
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* @dev_name: Name of device file. Maybe NULL.
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* @path: Pointer to "struct path".
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* @type: Name of filesystem type. Maybe NULL.
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* @flags: Mount options.
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* @data: Optional data. Maybe NULL.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_sb_mount(const char *dev_name, const struct path *path,
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const char *type, unsigned long flags, void *data)
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{
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return tomoyo_mount_permission(dev_name, path, type, flags, data);
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}
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/**
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* tomoyo_sb_umount - Target for security_sb_umount().
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*
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* @mnt: Pointer to "struct vfsmount".
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* @flags: Unmount options.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
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{
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struct path path = { .mnt = mnt, .dentry = mnt->mnt_root };
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return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path, NULL);
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}
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/**
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* tomoyo_sb_pivotroot - Target for security_sb_pivotroot().
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*
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* @old_path: Pointer to "struct path".
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* @new_path: Pointer to "struct path".
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_sb_pivotroot(const struct path *old_path, const struct path *new_path)
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{
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return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
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}
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/**
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* tomoyo_socket_listen - Check permission for listen().
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*
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* @sock: Pointer to "struct socket".
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* @backlog: Backlog parameter.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_socket_listen(struct socket *sock, int backlog)
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{
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return tomoyo_socket_listen_permission(sock);
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}
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/**
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* tomoyo_socket_connect - Check permission for connect().
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*
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* @sock: Pointer to "struct socket".
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* @addr: Pointer to "struct sockaddr".
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* @addr_len: Size of @addr.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_socket_connect(struct socket *sock, struct sockaddr *addr,
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int addr_len)
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{
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return tomoyo_socket_connect_permission(sock, addr, addr_len);
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}
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/**
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* tomoyo_socket_bind - Check permission for bind().
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*
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* @sock: Pointer to "struct socket".
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* @addr: Pointer to "struct sockaddr".
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* @addr_len: Size of @addr.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_socket_bind(struct socket *sock, struct sockaddr *addr,
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int addr_len)
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{
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return tomoyo_socket_bind_permission(sock, addr, addr_len);
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}
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/**
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* tomoyo_socket_sendmsg - Check permission for sendmsg().
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*
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* @sock: Pointer to "struct socket".
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* @msg: Pointer to "struct msghdr".
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* @size: Size of message.
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*
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* Returns 0 on success, negative value otherwise.
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*/
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static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg,
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int size)
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{
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return tomoyo_socket_sendmsg_permission(sock, msg, size);
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}
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/*
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* tomoyo_security_ops is a "struct security_operations" which is used for
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* registering TOMOYO.
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*/
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static struct security_hook_list tomoyo_hooks[] __lsm_ro_after_init = {
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LSM_HOOK_INIT(cred_alloc_blank, tomoyo_cred_alloc_blank),
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LSM_HOOK_INIT(cred_prepare, tomoyo_cred_prepare),
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LSM_HOOK_INIT(cred_transfer, tomoyo_cred_transfer),
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LSM_HOOK_INIT(cred_free, tomoyo_cred_free),
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LSM_HOOK_INIT(bprm_set_creds, tomoyo_bprm_set_creds),
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LSM_HOOK_INIT(bprm_check_security, tomoyo_bprm_check_security),
|
|
LSM_HOOK_INIT(file_fcntl, tomoyo_file_fcntl),
|
|
LSM_HOOK_INIT(file_open, tomoyo_file_open),
|
|
LSM_HOOK_INIT(path_truncate, tomoyo_path_truncate),
|
|
LSM_HOOK_INIT(path_unlink, tomoyo_path_unlink),
|
|
LSM_HOOK_INIT(path_mkdir, tomoyo_path_mkdir),
|
|
LSM_HOOK_INIT(path_rmdir, tomoyo_path_rmdir),
|
|
LSM_HOOK_INIT(path_symlink, tomoyo_path_symlink),
|
|
LSM_HOOK_INIT(path_mknod, tomoyo_path_mknod),
|
|
LSM_HOOK_INIT(path_link, tomoyo_path_link),
|
|
LSM_HOOK_INIT(path_rename, tomoyo_path_rename),
|
|
LSM_HOOK_INIT(inode_getattr, tomoyo_inode_getattr),
|
|
LSM_HOOK_INIT(file_ioctl, tomoyo_file_ioctl),
|
|
LSM_HOOK_INIT(path_chmod, tomoyo_path_chmod),
|
|
LSM_HOOK_INIT(path_chown, tomoyo_path_chown),
|
|
LSM_HOOK_INIT(path_chroot, tomoyo_path_chroot),
|
|
LSM_HOOK_INIT(sb_mount, tomoyo_sb_mount),
|
|
LSM_HOOK_INIT(sb_umount, tomoyo_sb_umount),
|
|
LSM_HOOK_INIT(sb_pivotroot, tomoyo_sb_pivotroot),
|
|
LSM_HOOK_INIT(socket_bind, tomoyo_socket_bind),
|
|
LSM_HOOK_INIT(socket_connect, tomoyo_socket_connect),
|
|
LSM_HOOK_INIT(socket_listen, tomoyo_socket_listen),
|
|
LSM_HOOK_INIT(socket_sendmsg, tomoyo_socket_sendmsg),
|
|
};
|
|
|
|
/* Lock for GC. */
|
|
DEFINE_SRCU(tomoyo_ss);
|
|
|
|
/**
|
|
* tomoyo_init - Register TOMOYO Linux as a LSM module.
|
|
*
|
|
* Returns 0.
|
|
*/
|
|
static int __init tomoyo_init(void)
|
|
{
|
|
struct cred *cred = (struct cred *) current_cred();
|
|
|
|
/* register ourselves with the security framework */
|
|
security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
|
|
printk(KERN_INFO "TOMOYO Linux initialized\n");
|
|
cred->security = &tomoyo_kernel_domain;
|
|
tomoyo_mm_init();
|
|
return 0;
|
|
}
|
|
|
|
DEFINE_LSM(tomoyo) = {
|
|
.name = "tomoyo",
|
|
.flags = LSM_FLAG_LEGACY_MAJOR,
|
|
.init = tomoyo_init,
|
|
};
|