| /* |
| * security/tomoyo/domain.c |
| * |
| * Domain transition functions for TOMOYO. |
| * |
| * Copyright (C) 2005-2010 NTT DATA CORPORATION |
| */ |
| |
| #include "common.h" |
| #include <linux/binfmts.h> |
| #include <linux/slab.h> |
| |
| /* Variables definitions.*/ |
| |
| /* The initial domain. */ |
| struct tomoyo_domain_info tomoyo_kernel_domain; |
| |
| /** |
| * tomoyo_update_domain - Update an entry for domain policy. |
| * |
| * @new_entry: Pointer to "struct tomoyo_acl_info". |
| * @size: Size of @new_entry in bytes. |
| * @is_delete: True if it is a delete request. |
| * @domain: Pointer to "struct tomoyo_domain_info". |
| * @check_duplicate: Callback function to find duplicated entry. |
| * @merge_duplicate: Callback function to merge duplicated entry. |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size, |
| bool is_delete, struct tomoyo_domain_info *domain, |
| bool (*check_duplicate) (const struct tomoyo_acl_info |
| *, |
| const struct tomoyo_acl_info |
| *), |
| bool (*merge_duplicate) (struct tomoyo_acl_info *, |
| struct tomoyo_acl_info *, |
| const bool)) |
| { |
| int error = is_delete ? -ENOENT : -ENOMEM; |
| struct tomoyo_acl_info *entry; |
| |
| if (mutex_lock_interruptible(&tomoyo_policy_lock)) |
| return error; |
| list_for_each_entry_rcu(entry, &domain->acl_info_list, list) { |
| if (!check_duplicate(entry, new_entry)) |
| continue; |
| if (merge_duplicate) |
| entry->is_deleted = merge_duplicate(entry, new_entry, |
| is_delete); |
| else |
| entry->is_deleted = is_delete; |
| error = 0; |
| break; |
| } |
| if (error && !is_delete) { |
| entry = tomoyo_commit_ok(new_entry, size); |
| if (entry) { |
| list_add_tail_rcu(&entry->list, &domain->acl_info_list); |
| error = 0; |
| } |
| } |
| mutex_unlock(&tomoyo_policy_lock); |
| return error; |
| } |
| |
| /* |
| * tomoyo_domain_list is used for holding list of domains. |
| * The ->acl_info_list of "struct tomoyo_domain_info" is used for holding |
| * permissions (e.g. "allow_read /lib/libc-2.5.so") given to each domain. |
| * |
| * An entry is added by |
| * |
| * # ( echo "<kernel>"; echo "allow_execute /sbin/init" ) > \ |
| * /sys/kernel/security/tomoyo/domain_policy |
| * |
| * and is deleted by |
| * |
| * # ( echo "<kernel>"; echo "delete allow_execute /sbin/init" ) > \ |
| * /sys/kernel/security/tomoyo/domain_policy |
| * |
| * and all entries are retrieved by |
| * |
| * # cat /sys/kernel/security/tomoyo/domain_policy |
| * |
| * A domain is added by |
| * |
| * # echo "<kernel>" > /sys/kernel/security/tomoyo/domain_policy |
| * |
| * and is deleted by |
| * |
| * # echo "delete <kernel>" > /sys/kernel/security/tomoyo/domain_policy |
| * |
| * and all domains are retrieved by |
| * |
| * # grep '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
| * |
| * Normally, a domainname is monotonically getting longer because a domainname |
| * which the process will belong to if an execve() operation succeeds is |
| * defined as a concatenation of "current domainname" + "pathname passed to |
| * execve()". |
| * See tomoyo_domain_initializer_list and tomoyo_domain_keeper_list for |
| * exceptions. |
| */ |
| LIST_HEAD(tomoyo_domain_list); |
| |
| /** |
| * tomoyo_get_last_name - Get last component of a domainname. |
| * |
| * @domain: Pointer to "struct tomoyo_domain_info". |
| * |
| * Returns the last component of the domainname. |
| */ |
| const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain) |
| { |
| const char *cp0 = domain->domainname->name; |
| const char *cp1 = strrchr(cp0, ' '); |
| |
| if (cp1) |
| return cp1 + 1; |
| return cp0; |
| } |
| |
| /* |
| * tomoyo_domain_initializer_list is used for holding list of programs which |
| * triggers reinitialization of domainname. Normally, a domainname is |
| * monotonically getting longer. But sometimes, we restart daemon programs. |
| * It would be convenient for us that "a daemon started upon system boot" and |
| * "the daemon restarted from console" belong to the same domain. Thus, TOMOYO |
| * provides a way to shorten domainnames. |
| * |
| * An entry is added by |
| * |
| * # echo 'initialize_domain /usr/sbin/httpd' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * |
| * and is deleted by |
| * |
| * # echo 'delete initialize_domain /usr/sbin/httpd' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * |
| * and all entries are retrieved by |
| * |
| * # grep ^initialize_domain /sys/kernel/security/tomoyo/exception_policy |
| * |
| * In the example above, /usr/sbin/httpd will belong to |
| * "<kernel> /usr/sbin/httpd" domain. |
| * |
| * You may specify a domainname using "from" keyword. |
| * "initialize_domain /usr/sbin/httpd from <kernel> /etc/rc.d/init.d/httpd" |
| * will cause "/usr/sbin/httpd" executed from "<kernel> /etc/rc.d/init.d/httpd" |
| * domain to belong to "<kernel> /usr/sbin/httpd" domain. |
| * |
| * You may add "no_" prefix to "initialize_domain". |
| * "initialize_domain /usr/sbin/httpd" and |
| * "no_initialize_domain /usr/sbin/httpd from <kernel> /etc/rc.d/init.d/httpd" |
| * will cause "/usr/sbin/httpd" to belong to "<kernel> /usr/sbin/httpd" domain |
| * unless executed from "<kernel> /etc/rc.d/init.d/httpd" domain. |
| */ |
| LIST_HEAD(tomoyo_domain_initializer_list); |
| |
| /** |
| * tomoyo_update_domain_initializer_entry - Update "struct tomoyo_domain_initializer_entry" list. |
| * |
| * @domainname: The name of domain. May be NULL. |
| * @program: The name of program. |
| * @is_not: True if it is "no_initialize_domain" entry. |
| * @is_delete: True if it is a delete request. |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| static int tomoyo_update_domain_initializer_entry(const char *domainname, |
| const char *program, |
| const bool is_not, |
| const bool is_delete) |
| { |
| struct tomoyo_domain_initializer_entry *ptr; |
| struct tomoyo_domain_initializer_entry e = { .is_not = is_not }; |
| int error = is_delete ? -ENOENT : -ENOMEM; |
| |
| if (!tomoyo_is_correct_path(program)) |
| return -EINVAL; |
| if (domainname) { |
| if (!tomoyo_is_domain_def(domainname) && |
| tomoyo_is_correct_path(domainname)) |
| e.is_last_name = true; |
| else if (!tomoyo_is_correct_domain(domainname)) |
| return -EINVAL; |
| e.domainname = tomoyo_get_name(domainname); |
| if (!e.domainname) |
| goto out; |
| } |
| e.program = tomoyo_get_name(program); |
| if (!e.program) |
| goto out; |
| if (mutex_lock_interruptible(&tomoyo_policy_lock)) |
| goto out; |
| list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list, list) { |
| if (!tomoyo_is_same_domain_initializer_entry(ptr, &e)) |
| continue; |
| ptr->is_deleted = is_delete; |
| error = 0; |
| break; |
| } |
| if (!is_delete && error) { |
| struct tomoyo_domain_initializer_entry *entry = |
| tomoyo_commit_ok(&e, sizeof(e)); |
| if (entry) { |
| list_add_tail_rcu(&entry->list, |
| &tomoyo_domain_initializer_list); |
| error = 0; |
| } |
| } |
| mutex_unlock(&tomoyo_policy_lock); |
| out: |
| tomoyo_put_name(e.domainname); |
| tomoyo_put_name(e.program); |
| return error; |
| } |
| |
| /** |
| * tomoyo_read_domain_initializer_policy - Read "struct tomoyo_domain_initializer_entry" list. |
| * |
| * @head: Pointer to "struct tomoyo_io_buffer". |
| * |
| * Returns true on success, false otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| bool tomoyo_read_domain_initializer_policy(struct tomoyo_io_buffer *head) |
| { |
| struct list_head *pos; |
| bool done = true; |
| |
| list_for_each_cookie(pos, head->read_var2, |
| &tomoyo_domain_initializer_list) { |
| const char *no; |
| const char *from = ""; |
| const char *domain = ""; |
| struct tomoyo_domain_initializer_entry *ptr; |
| ptr = list_entry(pos, struct tomoyo_domain_initializer_entry, |
| list); |
| if (ptr->is_deleted) |
| continue; |
| no = ptr->is_not ? "no_" : ""; |
| if (ptr->domainname) { |
| from = " from "; |
| domain = ptr->domainname->name; |
| } |
| done = tomoyo_io_printf(head, |
| "%s" TOMOYO_KEYWORD_INITIALIZE_DOMAIN |
| "%s%s%s\n", no, ptr->program->name, |
| from, domain); |
| if (!done) |
| break; |
| } |
| return done; |
| } |
| |
| /** |
| * tomoyo_write_domain_initializer_policy - Write "struct tomoyo_domain_initializer_entry" list. |
| * |
| * @data: String to parse. |
| * @is_not: True if it is "no_initialize_domain" entry. |
| * @is_delete: True if it is a delete request. |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| int tomoyo_write_domain_initializer_policy(char *data, const bool is_not, |
| const bool is_delete) |
| { |
| char *cp = strstr(data, " from "); |
| |
| if (cp) { |
| *cp = '\0'; |
| return tomoyo_update_domain_initializer_entry(cp + 6, data, |
| is_not, |
| is_delete); |
| } |
| return tomoyo_update_domain_initializer_entry(NULL, data, is_not, |
| is_delete); |
| } |
| |
| /** |
| * tomoyo_is_domain_initializer - Check whether the given program causes domainname reinitialization. |
| * |
| * @domainname: The name of domain. |
| * @program: The name of program. |
| * @last_name: The last component of @domainname. |
| * |
| * Returns true if executing @program reinitializes domain transition, |
| * false otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| static bool tomoyo_is_domain_initializer(const struct tomoyo_path_info * |
| domainname, |
| const struct tomoyo_path_info *program, |
| const struct tomoyo_path_info * |
| last_name) |
| { |
| struct tomoyo_domain_initializer_entry *ptr; |
| bool flag = false; |
| |
| list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list, list) { |
| if (ptr->is_deleted) |
| continue; |
| if (ptr->domainname) { |
| if (!ptr->is_last_name) { |
| if (ptr->domainname != domainname) |
| continue; |
| } else { |
| if (tomoyo_pathcmp(ptr->domainname, last_name)) |
| continue; |
| } |
| } |
| if (tomoyo_pathcmp(ptr->program, program)) |
| continue; |
| if (ptr->is_not) { |
| flag = false; |
| break; |
| } |
| flag = true; |
| } |
| return flag; |
| } |
| |
| /* |
| * tomoyo_domain_keeper_list is used for holding list of domainnames which |
| * suppresses domain transition. Normally, a domainname is monotonically |
| * getting longer. But sometimes, we want to suppress domain transition. |
| * It would be convenient for us that programs executed from a login session |
| * belong to the same domain. Thus, TOMOYO provides a way to suppress domain |
| * transition. |
| * |
| * An entry is added by |
| * |
| * # echo 'keep_domain <kernel> /usr/sbin/sshd /bin/bash' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * |
| * and is deleted by |
| * |
| * # echo 'delete keep_domain <kernel> /usr/sbin/sshd /bin/bash' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * |
| * and all entries are retrieved by |
| * |
| * # grep ^keep_domain /sys/kernel/security/tomoyo/exception_policy |
| * |
| * In the example above, any process which belongs to |
| * "<kernel> /usr/sbin/sshd /bin/bash" domain will remain in that domain, |
| * unless explicitly specified by "initialize_domain" or "no_keep_domain". |
| * |
| * You may specify a program using "from" keyword. |
| * "keep_domain /bin/pwd from <kernel> /usr/sbin/sshd /bin/bash" |
| * will cause "/bin/pwd" executed from "<kernel> /usr/sbin/sshd /bin/bash" |
| * domain to remain in "<kernel> /usr/sbin/sshd /bin/bash" domain. |
| * |
| * You may add "no_" prefix to "keep_domain". |
| * "keep_domain <kernel> /usr/sbin/sshd /bin/bash" and |
| * "no_keep_domain /usr/bin/passwd from <kernel> /usr/sbin/sshd /bin/bash" will |
| * cause "/usr/bin/passwd" to belong to |
| * "<kernel> /usr/sbin/sshd /bin/bash /usr/bin/passwd" domain, unless |
| * explicitly specified by "initialize_domain". |
| */ |
| LIST_HEAD(tomoyo_domain_keeper_list); |
| |
| /** |
| * tomoyo_update_domain_keeper_entry - Update "struct tomoyo_domain_keeper_entry" list. |
| * |
| * @domainname: The name of domain. |
| * @program: The name of program. May be NULL. |
| * @is_not: True if it is "no_keep_domain" entry. |
| * @is_delete: True if it is a delete request. |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| static int tomoyo_update_domain_keeper_entry(const char *domainname, |
| const char *program, |
| const bool is_not, |
| const bool is_delete) |
| { |
| struct tomoyo_domain_keeper_entry *ptr; |
| struct tomoyo_domain_keeper_entry e = { .is_not = is_not }; |
| int error = is_delete ? -ENOENT : -ENOMEM; |
| |
| if (!tomoyo_is_domain_def(domainname) && |
| tomoyo_is_correct_path(domainname)) |
| e.is_last_name = true; |
| else if (!tomoyo_is_correct_domain(domainname)) |
| return -EINVAL; |
| if (program) { |
| if (!tomoyo_is_correct_path(program)) |
| return -EINVAL; |
| e.program = tomoyo_get_name(program); |
| if (!e.program) |
| goto out; |
| } |
| e.domainname = tomoyo_get_name(domainname); |
| if (!e.domainname) |
| goto out; |
| if (mutex_lock_interruptible(&tomoyo_policy_lock)) |
| goto out; |
| list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, list) { |
| if (!tomoyo_is_same_domain_keeper_entry(ptr, &e)) |
| continue; |
| ptr->is_deleted = is_delete; |
| error = 0; |
| break; |
| } |
| if (!is_delete && error) { |
| struct tomoyo_domain_keeper_entry *entry = |
| tomoyo_commit_ok(&e, sizeof(e)); |
| if (entry) { |
| list_add_tail_rcu(&entry->list, |
| &tomoyo_domain_keeper_list); |
| error = 0; |
| } |
| } |
| mutex_unlock(&tomoyo_policy_lock); |
| out: |
| tomoyo_put_name(e.domainname); |
| tomoyo_put_name(e.program); |
| return error; |
| } |
| |
| /** |
| * tomoyo_write_domain_keeper_policy - Write "struct tomoyo_domain_keeper_entry" list. |
| * |
| * @data: String to parse. |
| * @is_not: True if it is "no_keep_domain" entry. |
| * @is_delete: True if it is a delete request. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| int tomoyo_write_domain_keeper_policy(char *data, const bool is_not, |
| const bool is_delete) |
| { |
| char *cp = strstr(data, " from "); |
| |
| if (cp) { |
| *cp = '\0'; |
| return tomoyo_update_domain_keeper_entry(cp + 6, data, is_not, |
| is_delete); |
| } |
| return tomoyo_update_domain_keeper_entry(data, NULL, is_not, is_delete); |
| } |
| |
| /** |
| * tomoyo_read_domain_keeper_policy - Read "struct tomoyo_domain_keeper_entry" list. |
| * |
| * @head: Pointer to "struct tomoyo_io_buffer". |
| * |
| * Returns true on success, false otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| bool tomoyo_read_domain_keeper_policy(struct tomoyo_io_buffer *head) |
| { |
| struct list_head *pos; |
| bool done = true; |
| |
| list_for_each_cookie(pos, head->read_var2, |
| &tomoyo_domain_keeper_list) { |
| struct tomoyo_domain_keeper_entry *ptr; |
| const char *no; |
| const char *from = ""; |
| const char *program = ""; |
| |
| ptr = list_entry(pos, struct tomoyo_domain_keeper_entry, list); |
| if (ptr->is_deleted) |
| continue; |
| no = ptr->is_not ? "no_" : ""; |
| if (ptr->program) { |
| from = " from "; |
| program = ptr->program->name; |
| } |
| done = tomoyo_io_printf(head, |
| "%s" TOMOYO_KEYWORD_KEEP_DOMAIN |
| "%s%s%s\n", no, program, from, |
| ptr->domainname->name); |
| if (!done) |
| break; |
| } |
| return done; |
| } |
| |
| /** |
| * tomoyo_is_domain_keeper - Check whether the given program causes domain transition suppression. |
| * |
| * @domainname: The name of domain. |
| * @program: The name of program. |
| * @last_name: The last component of @domainname. |
| * |
| * Returns true if executing @program supresses domain transition, |
| * false otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| static bool tomoyo_is_domain_keeper(const struct tomoyo_path_info *domainname, |
| const struct tomoyo_path_info *program, |
| const struct tomoyo_path_info *last_name) |
| { |
| struct tomoyo_domain_keeper_entry *ptr; |
| bool flag = false; |
| |
| list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, list) { |
| if (ptr->is_deleted) |
| continue; |
| if (!ptr->is_last_name) { |
| if (ptr->domainname != domainname) |
| continue; |
| } else { |
| if (tomoyo_pathcmp(ptr->domainname, last_name)) |
| continue; |
| } |
| if (ptr->program && tomoyo_pathcmp(ptr->program, program)) |
| continue; |
| if (ptr->is_not) { |
| flag = false; |
| break; |
| } |
| flag = true; |
| } |
| return flag; |
| } |
| |
| /* |
| * tomoyo_aggregator_list is used for holding list of rewrite table for |
| * execve() request. Some programs provides similar functionality. This keyword |
| * allows users to aggregate such programs. |
| * |
| * Entries are added by |
| * |
| * # echo 'aggregator /usr/bin/vi /./editor' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * # echo 'aggregator /usr/bin/emacs /./editor' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * |
| * and are deleted by |
| * |
| * # echo 'delete aggregator /usr/bin/vi /./editor' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * # echo 'delete aggregator /usr/bin/emacs /./editor' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * |
| * and all entries are retrieved by |
| * |
| * # grep ^aggregator /sys/kernel/security/tomoyo/exception_policy |
| * |
| * In the example above, if /usr/bin/vi or /usr/bin/emacs are executed, |
| * permission is checked for /./editor and domainname which the current process |
| * will belong to after execve() succeeds is calculated using /./editor . |
| */ |
| LIST_HEAD(tomoyo_aggregator_list); |
| |
| /** |
| * tomoyo_update_aggregator_entry - Update "struct tomoyo_aggregator_entry" list. |
| * |
| * @original_name: The original program's name. |
| * @aggregated_name: The program name to use. |
| * @is_delete: True if it is a delete request. |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| static int tomoyo_update_aggregator_entry(const char *original_name, |
| const char *aggregated_name, |
| const bool is_delete) |
| { |
| struct tomoyo_aggregator_entry *ptr; |
| struct tomoyo_aggregator_entry e = { }; |
| int error = is_delete ? -ENOENT : -ENOMEM; |
| |
| if (!tomoyo_is_correct_path(original_name) || |
| !tomoyo_is_correct_path(aggregated_name)) |
| return -EINVAL; |
| e.original_name = tomoyo_get_name(original_name); |
| e.aggregated_name = tomoyo_get_name(aggregated_name); |
| if (!e.original_name || !e.aggregated_name || |
| e.aggregated_name->is_patterned) /* No patterns allowed. */ |
| goto out; |
| if (mutex_lock_interruptible(&tomoyo_policy_lock)) |
| goto out; |
| list_for_each_entry_rcu(ptr, &tomoyo_aggregator_list, list) { |
| if (!tomoyo_is_same_aggregator_entry(ptr, &e)) |
| continue; |
| ptr->is_deleted = is_delete; |
| error = 0; |
| break; |
| } |
| if (!is_delete && error) { |
| struct tomoyo_aggregator_entry *entry = |
| tomoyo_commit_ok(&e, sizeof(e)); |
| if (entry) { |
| list_add_tail_rcu(&entry->list, |
| &tomoyo_aggregator_list); |
| error = 0; |
| } |
| } |
| mutex_unlock(&tomoyo_policy_lock); |
| out: |
| tomoyo_put_name(e.original_name); |
| tomoyo_put_name(e.aggregated_name); |
| return error; |
| } |
| |
| /** |
| * tomoyo_read_aggregator_policy - Read "struct tomoyo_aggregator_entry" list. |
| * |
| * @head: Pointer to "struct tomoyo_io_buffer". |
| * |
| * Returns true on success, false otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| bool tomoyo_read_aggregator_policy(struct tomoyo_io_buffer *head) |
| { |
| struct list_head *pos; |
| bool done = true; |
| |
| list_for_each_cookie(pos, head->read_var2, &tomoyo_aggregator_list) { |
| struct tomoyo_aggregator_entry *ptr; |
| |
| ptr = list_entry(pos, struct tomoyo_aggregator_entry, list); |
| if (ptr->is_deleted) |
| continue; |
| done = tomoyo_io_printf(head, TOMOYO_KEYWORD_AGGREGATOR |
| "%s %s\n", ptr->original_name->name, |
| ptr->aggregated_name->name); |
| if (!done) |
| break; |
| } |
| return done; |
| } |
| |
| /** |
| * tomoyo_write_aggregator_policy - Write "struct tomoyo_aggregator_entry" list. |
| * |
| * @data: String to parse. |
| * @is_delete: True if it is a delete request. |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| int tomoyo_write_aggregator_policy(char *data, const bool is_delete) |
| { |
| char *cp = strchr(data, ' '); |
| |
| if (!cp) |
| return -EINVAL; |
| *cp++ = '\0'; |
| return tomoyo_update_aggregator_entry(data, cp, is_delete); |
| } |
| |
| /* |
| * tomoyo_alias_list is used for holding list of symlink's pathnames which are |
| * allowed to be passed to an execve() request. Normally, the domainname which |
| * the current process will belong to after execve() succeeds is calculated |
| * using dereferenced pathnames. But some programs behave differently depending |
| * on the name passed to argv[0]. For busybox, calculating domainname using |
| * dereferenced pathnames will cause all programs in the busybox to belong to |
| * the same domain. Thus, TOMOYO provides a way to allow use of symlink's |
| * pathname for checking execve()'s permission and calculating domainname which |
| * the current process will belong to after execve() succeeds. |
| * |
| * An entry is added by |
| * |
| * # echo 'alias /bin/busybox /bin/cat' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * |
| * and is deleted by |
| * |
| * # echo 'delete alias /bin/busybox /bin/cat' > \ |
| * /sys/kernel/security/tomoyo/exception_policy |
| * |
| * and all entries are retrieved by |
| * |
| * # grep ^alias /sys/kernel/security/tomoyo/exception_policy |
| * |
| * In the example above, if /bin/cat is a symlink to /bin/busybox and execution |
| * of /bin/cat is requested, permission is checked for /bin/cat rather than |
| * /bin/busybox and domainname which the current process will belong to after |
| * execve() succeeds is calculated using /bin/cat rather than /bin/busybox . |
| */ |
| LIST_HEAD(tomoyo_alias_list); |
| |
| /** |
| * tomoyo_update_alias_entry - Update "struct tomoyo_alias_entry" list. |
| * |
| * @original_name: The original program's real name. |
| * @aliased_name: The symbolic program's symbolic link's name. |
| * @is_delete: True if it is a delete request. |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| static int tomoyo_update_alias_entry(const char *original_name, |
| const char *aliased_name, |
| const bool is_delete) |
| { |
| struct tomoyo_alias_entry *ptr; |
| struct tomoyo_alias_entry e = { }; |
| int error = is_delete ? -ENOENT : -ENOMEM; |
| |
| if (!tomoyo_is_correct_path(original_name) || |
| !tomoyo_is_correct_path(aliased_name)) |
| return -EINVAL; |
| e.original_name = tomoyo_get_name(original_name); |
| e.aliased_name = tomoyo_get_name(aliased_name); |
| if (!e.original_name || !e.aliased_name || |
| e.original_name->is_patterned || e.aliased_name->is_patterned) |
| goto out; /* No patterns allowed. */ |
| if (mutex_lock_interruptible(&tomoyo_policy_lock)) |
| goto out; |
| list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) { |
| if (!tomoyo_is_same_alias_entry(ptr, &e)) |
| continue; |
| ptr->is_deleted = is_delete; |
| error = 0; |
| break; |
| } |
| if (!is_delete && error) { |
| struct tomoyo_alias_entry *entry = |
| tomoyo_commit_ok(&e, sizeof(e)); |
| if (entry) { |
| list_add_tail_rcu(&entry->list, &tomoyo_alias_list); |
| error = 0; |
| } |
| } |
| mutex_unlock(&tomoyo_policy_lock); |
| out: |
| tomoyo_put_name(e.original_name); |
| tomoyo_put_name(e.aliased_name); |
| return error; |
| } |
| |
| /** |
| * tomoyo_read_alias_policy - Read "struct tomoyo_alias_entry" list. |
| * |
| * @head: Pointer to "struct tomoyo_io_buffer". |
| * |
| * Returns true on success, false otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head) |
| { |
| struct list_head *pos; |
| bool done = true; |
| |
| list_for_each_cookie(pos, head->read_var2, &tomoyo_alias_list) { |
| struct tomoyo_alias_entry *ptr; |
| |
| ptr = list_entry(pos, struct tomoyo_alias_entry, list); |
| if (ptr->is_deleted) |
| continue; |
| done = tomoyo_io_printf(head, TOMOYO_KEYWORD_ALIAS "%s %s\n", |
| ptr->original_name->name, |
| ptr->aliased_name->name); |
| if (!done) |
| break; |
| } |
| return done; |
| } |
| |
| /** |
| * tomoyo_write_alias_policy - Write "struct tomoyo_alias_entry" list. |
| * |
| * @data: String to parse. |
| * @is_delete: True if it is a delete request. |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| int tomoyo_write_alias_policy(char *data, const bool is_delete) |
| { |
| char *cp = strchr(data, ' '); |
| |
| if (!cp) |
| return -EINVAL; |
| *cp++ = '\0'; |
| return tomoyo_update_alias_entry(data, cp, is_delete); |
| } |
| |
| /** |
| * tomoyo_find_or_assign_new_domain - Create a domain. |
| * |
| * @domainname: The name of domain. |
| * @profile: Profile number to assign if the domain was newly created. |
| * |
| * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * |
| domainname, |
| const u8 profile) |
| { |
| struct tomoyo_domain_info *entry; |
| struct tomoyo_domain_info *domain = NULL; |
| const struct tomoyo_path_info *saved_domainname; |
| bool found = false; |
| |
| if (!tomoyo_is_correct_domain(domainname)) |
| return NULL; |
| saved_domainname = tomoyo_get_name(domainname); |
| if (!saved_domainname) |
| return NULL; |
| entry = kzalloc(sizeof(*entry), GFP_NOFS); |
| if (mutex_lock_interruptible(&tomoyo_policy_lock)) |
| goto out; |
| list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) { |
| if (domain->is_deleted || |
| tomoyo_pathcmp(saved_domainname, domain->domainname)) |
| continue; |
| found = true; |
| break; |
| } |
| if (!found && tomoyo_memory_ok(entry)) { |
| INIT_LIST_HEAD(&entry->acl_info_list); |
| entry->domainname = saved_domainname; |
| saved_domainname = NULL; |
| entry->profile = profile; |
| list_add_tail_rcu(&entry->list, &tomoyo_domain_list); |
| domain = entry; |
| entry = NULL; |
| found = true; |
| } |
| mutex_unlock(&tomoyo_policy_lock); |
| out: |
| tomoyo_put_name(saved_domainname); |
| kfree(entry); |
| return found ? domain : NULL; |
| } |
| |
| /** |
| * tomoyo_find_next_domain - Find a domain. |
| * |
| * @bprm: Pointer to "struct linux_binprm". |
| * |
| * Returns 0 on success, negative value otherwise. |
| * |
| * Caller holds tomoyo_read_lock(). |
| */ |
| int tomoyo_find_next_domain(struct linux_binprm *bprm) |
| { |
| struct tomoyo_request_info r; |
| char *tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS); |
| struct tomoyo_domain_info *old_domain = tomoyo_domain(); |
| struct tomoyo_domain_info *domain = NULL; |
| const char *old_domain_name = old_domain->domainname->name; |
| const char *original_name = bprm->filename; |
| u8 mode; |
| bool is_enforce; |
| int retval = -ENOMEM; |
| bool need_kfree = false; |
| struct tomoyo_path_info rn = { }; /* real name */ |
| struct tomoyo_path_info sn = { }; /* symlink name */ |
| struct tomoyo_path_info ln; /* last name */ |
| |
| ln.name = tomoyo_get_last_name(old_domain); |
| tomoyo_fill_path_info(&ln); |
| mode = tomoyo_init_request_info(&r, NULL, TOMOYO_MAC_FILE_EXECUTE); |
| is_enforce = (mode == TOMOYO_CONFIG_ENFORCING); |
| if (!tmp) |
| goto out; |
| |
| retry: |
| if (need_kfree) { |
| kfree(rn.name); |
| need_kfree = false; |
| } |
| /* Get tomoyo_realpath of program. */ |
| retval = -ENOENT; |
| rn.name = tomoyo_realpath(original_name); |
| if (!rn.name) |
| goto out; |
| tomoyo_fill_path_info(&rn); |
| need_kfree = true; |
| |
| /* Get tomoyo_realpath of symbolic link. */ |
| sn.name = tomoyo_realpath_nofollow(original_name); |
| if (!sn.name) |
| goto out; |
| tomoyo_fill_path_info(&sn); |
| |
| /* Check 'alias' directive. */ |
| if (tomoyo_pathcmp(&rn, &sn)) { |
| struct tomoyo_alias_entry *ptr; |
| /* Is this program allowed to be called via symbolic links? */ |
| list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) { |
| if (ptr->is_deleted || |
| tomoyo_pathcmp(&rn, ptr->original_name) || |
| tomoyo_pathcmp(&sn, ptr->aliased_name)) |
| continue; |
| kfree(rn.name); |
| need_kfree = false; |
| /* This is OK because it is read only. */ |
| rn = *ptr->aliased_name; |
| break; |
| } |
| } |
| |
| /* Check 'aggregator' directive. */ |
| { |
| struct tomoyo_aggregator_entry *ptr; |
| list_for_each_entry_rcu(ptr, &tomoyo_aggregator_list, list) { |
| if (ptr->is_deleted || |
| !tomoyo_path_matches_pattern(&rn, |
| ptr->original_name)) |
| continue; |
| if (need_kfree) |
| kfree(rn.name); |
| need_kfree = false; |
| /* This is OK because it is read only. */ |
| rn = *ptr->aggregated_name; |
| break; |
| } |
| } |
| |
| /* Check execute permission. */ |
| retval = tomoyo_check_exec_perm(&r, &rn); |
| if (retval == TOMOYO_RETRY_REQUEST) |
| goto retry; |
| if (retval < 0) |
| goto out; |
| |
| if (tomoyo_is_domain_initializer(old_domain->domainname, &rn, &ln)) { |
| /* Transit to the child of tomoyo_kernel_domain domain. */ |
| snprintf(tmp, TOMOYO_EXEC_TMPSIZE - 1, |
| TOMOYO_ROOT_NAME " " "%s", rn.name); |
| } else if (old_domain == &tomoyo_kernel_domain && |
| !tomoyo_policy_loaded) { |
| /* |
| * Needn't to transit from kernel domain before starting |
| * /sbin/init. But transit from kernel domain if executing |
| * initializers because they might start before /sbin/init. |
| */ |
| domain = old_domain; |
| } else if (tomoyo_is_domain_keeper(old_domain->domainname, &rn, &ln)) { |
| /* Keep current domain. */ |
| domain = old_domain; |
| } else { |
| /* Normal domain transition. */ |
| snprintf(tmp, TOMOYO_EXEC_TMPSIZE - 1, |
| "%s %s", old_domain_name, rn.name); |
| } |
| if (domain || strlen(tmp) >= TOMOYO_EXEC_TMPSIZE - 10) |
| goto done; |
| domain = tomoyo_find_domain(tmp); |
| if (domain) |
| goto done; |
| if (is_enforce) { |
| int error = tomoyo_supervisor(&r, "# wants to create domain\n" |
| "%s\n", tmp); |
| if (error == TOMOYO_RETRY_REQUEST) |
| goto retry; |
| if (error < 0) |
| goto done; |
| } |
| domain = tomoyo_find_or_assign_new_domain(tmp, old_domain->profile); |
| done: |
| if (domain) |
| goto out; |
| printk(KERN_WARNING "TOMOYO-ERROR: Domain '%s' not defined.\n", tmp); |
| if (is_enforce) |
| retval = -EPERM; |
| else |
| old_domain->transition_failed = true; |
| out: |
| if (!domain) |
| domain = old_domain; |
| /* Update reference count on "struct tomoyo_domain_info". */ |
| atomic_inc(&domain->users); |
| bprm->cred->security = domain; |
| if (need_kfree) |
| kfree(rn.name); |
| kfree(sn.name); |
| kfree(tmp); |
| return retval; |
| } |