From 1084307ca097745ed6e40a192329b133a49271ac Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Thu, 3 Jun 2010 20:38:03 +0900 Subject: TOMOYO: Add pathname aggregation support. This patch allows users to aggregate programs which provide similar functionality (e.g. /usr/bin/vi and /usr/bin/emacs ). Signed-off-by: Tetsuo Handa Signed-off-by: James Morris --- security/tomoyo/domain.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) (limited to 'security/tomoyo/domain.c') diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c index 50f6e7972174..a07ca6dc1a08 100644 --- a/security/tomoyo/domain.c +++ b/security/tomoyo/domain.c @@ -482,6 +482,136 @@ static bool tomoyo_is_domain_keeper(const struct tomoyo_path_info *domainname, 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 @@ -732,6 +862,23 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm) } } + /* 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(old_domain, &rn); if (retval == TOMOYO_RETRY_REQUEST) -- cgit v1.2.2