295 строки
7.3 KiB
C
295 строки
7.3 KiB
C
/*
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* security/tomoyo/tomoyo.c
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*
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* LSM hooks for TOMOYO Linux.
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*
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* Copyright (C) 2005-2009 NTT DATA CORPORATION
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*
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* Version: 2.2.0 2009/04/01
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*
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*/
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#include <linux/security.h>
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#include "common.h"
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#include "tomoyo.h"
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#include "realpath.h"
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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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/*
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* Since "struct tomoyo_domain_info *" is a sharable pointer,
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* we don't need to duplicate.
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*/
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new->security = old->security;
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return 0;
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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->cred_prepared)
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return 0;
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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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/*
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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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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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struct tomoyo_domain_info *next_domain = NULL;
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int retval = tomoyo_find_next_domain(bprm, &next_domain);
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if (!retval)
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bprm->cred->security = next_domain;
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return retval;
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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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* '1' is the result of open_to_namei_flags(O_RDONLY).
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*/
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return tomoyo_check_open_permission(domain, &bprm->file->f_path, 1);
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}
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#ifdef CONFIG_SYSCTL
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static int tomoyo_prepend(char **buffer, int *buflen, const char *str)
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{
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int namelen = strlen(str);
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if (*buflen < namelen)
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return -ENOMEM;
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*buflen -= namelen;
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*buffer -= namelen;
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memcpy(*buffer, str, namelen);
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return 0;
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}
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/**
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* tomoyo_sysctl_path - return the realpath of a ctl_table.
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* @table: pointer to "struct ctl_table".
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*
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* Returns realpath(3) of the @table on success.
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* Returns NULL on failure.
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*
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* This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
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* if this function didn't return NULL.
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*/
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static char *tomoyo_sysctl_path(struct ctl_table *table)
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{
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int buflen = TOMOYO_MAX_PATHNAME_LEN;
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char *buf = tomoyo_alloc(buflen);
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char *end = buf + buflen;
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int error = -ENOMEM;
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if (!buf)
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return NULL;
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*--end = '\0';
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buflen--;
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while (table) {
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char num[32];
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const char *sp = table->procname;
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if (!sp) {
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memset(num, 0, sizeof(num));
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snprintf(num, sizeof(num) - 1, "=%d=", table->ctl_name);
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sp = num;
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}
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if (tomoyo_prepend(&end, &buflen, sp) ||
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tomoyo_prepend(&end, &buflen, "/"))
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goto out;
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table = table->parent;
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}
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if (tomoyo_prepend(&end, &buflen, "/proc/sys"))
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goto out;
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error = tomoyo_encode(buf, end - buf, end);
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out:
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if (!error)
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return buf;
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tomoyo_free(buf);
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return NULL;
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}
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static int tomoyo_sysctl(struct ctl_table *table, int op)
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{
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int error;
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char *name;
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op &= MAY_READ | MAY_WRITE;
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if (!op)
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return 0;
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name = tomoyo_sysctl_path(table);
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if (!name)
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return -ENOMEM;
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error = tomoyo_check_file_perm(tomoyo_domain(), name, op);
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tomoyo_free(name);
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return error;
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}
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#endif
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static int tomoyo_path_truncate(struct path *path, loff_t length,
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unsigned int time_attrs)
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{
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return tomoyo_check_1path_perm(tomoyo_domain(),
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TOMOYO_TYPE_TRUNCATE_ACL,
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path);
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}
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static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry)
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{
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struct path path = { parent->mnt, dentry };
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return tomoyo_check_1path_perm(tomoyo_domain(),
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TOMOYO_TYPE_UNLINK_ACL,
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&path);
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}
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static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
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int mode)
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{
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struct path path = { parent->mnt, dentry };
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return tomoyo_check_1path_perm(tomoyo_domain(),
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TOMOYO_TYPE_MKDIR_ACL,
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&path);
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}
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static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry)
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{
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struct path path = { parent->mnt, dentry };
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return tomoyo_check_1path_perm(tomoyo_domain(),
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TOMOYO_TYPE_RMDIR_ACL,
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&path);
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}
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static int tomoyo_path_symlink(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 = { parent->mnt, dentry };
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return tomoyo_check_1path_perm(tomoyo_domain(),
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TOMOYO_TYPE_SYMLINK_ACL,
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&path);
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}
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static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry,
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int mode, unsigned int dev)
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{
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struct path path = { parent->mnt, dentry };
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int type = TOMOYO_TYPE_CREATE_ACL;
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switch (mode & S_IFMT) {
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case S_IFCHR:
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type = TOMOYO_TYPE_MKCHAR_ACL;
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break;
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case S_IFBLK:
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type = TOMOYO_TYPE_MKBLOCK_ACL;
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break;
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case S_IFIFO:
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type = TOMOYO_TYPE_MKFIFO_ACL;
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break;
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case S_IFSOCK:
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type = TOMOYO_TYPE_MKSOCK_ACL;
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break;
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}
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return tomoyo_check_1path_perm(tomoyo_domain(),
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type, &path);
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}
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static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
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struct dentry *new_dentry)
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{
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struct path path1 = { new_dir->mnt, old_dentry };
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struct path path2 = { new_dir->mnt, new_dentry };
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return tomoyo_check_2path_perm(tomoyo_domain(),
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TOMOYO_TYPE_LINK_ACL,
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&path1, &path2);
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}
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static int tomoyo_path_rename(struct path *old_parent,
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struct dentry *old_dentry,
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struct path *new_parent,
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struct dentry *new_dentry)
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{
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struct path path1 = { old_parent->mnt, old_dentry };
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struct path path2 = { new_parent->mnt, new_dentry };
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return tomoyo_check_2path_perm(tomoyo_domain(),
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TOMOYO_TYPE_RENAME_ACL,
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&path1, &path2);
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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 tomoyo_check_rewrite_permission(tomoyo_domain(), file);
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return 0;
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}
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static int tomoyo_dentry_open(struct file *f, const struct cred *cred)
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{
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int flags = f->f_flags;
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if ((flags + 1) & O_ACCMODE)
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flags++;
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flags |= f->f_flags & (O_APPEND | O_TRUNC);
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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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static struct security_operations tomoyo_security_ops = {
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.name = "tomoyo",
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.cred_prepare = tomoyo_cred_prepare,
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.bprm_set_creds = tomoyo_bprm_set_creds,
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.bprm_check_security = tomoyo_bprm_check_security,
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#ifdef CONFIG_SYSCTL
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.sysctl = tomoyo_sysctl,
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#endif
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.file_fcntl = tomoyo_file_fcntl,
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.dentry_open = tomoyo_dentry_open,
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.path_truncate = tomoyo_path_truncate,
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.path_unlink = tomoyo_path_unlink,
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.path_mkdir = tomoyo_path_mkdir,
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.path_rmdir = tomoyo_path_rmdir,
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.path_symlink = tomoyo_path_symlink,
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.path_mknod = tomoyo_path_mknod,
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.path_link = tomoyo_path_link,
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.path_rename = tomoyo_path_rename,
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};
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static int __init tomoyo_init(void)
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{
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struct cred *cred = (struct cred *) current_cred();
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if (!security_module_enable(&tomoyo_security_ops))
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return 0;
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/* register ourselves with the security framework */
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if (register_security(&tomoyo_security_ops))
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panic("Failure registering TOMOYO Linux");
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printk(KERN_INFO "TOMOYO Linux initialized\n");
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cred->security = &tomoyo_kernel_domain;
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tomoyo_realpath_init();
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return 0;
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}
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security_initcall(tomoyo_init);
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