diff options
Diffstat (limited to 'security/tomoyo/domain.c')
| -rw-r--r-- | security/tomoyo/domain.c | 240 |
1 files changed, 200 insertions, 40 deletions
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c index 2d6748741a2..1d8b1696057 100644 --- a/security/tomoyo/domain.c +++ b/security/tomoyo/domain.c @@ -19,11 +19,63 @@ /* The initial domain. */ struct tomoyo_domain_info tomoyo_kernel_domain; -/* The list for "struct tomoyo_domain_info". */ +/* + * 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); DECLARE_RWSEM(tomoyo_domain_list_lock); -/* Structure for "initialize_domain" and "no_initialize_domain" keyword. */ +/* + * tomoyo_domain_initializer_entry is a structure which is used for holding + * "initialize_domain" and "no_initialize_domain" entries. + * It has following fields. + * + * (1) "list" which is linked to tomoyo_domain_initializer_list . + * (2) "domainname" which is "a domainname" or "the last component of a + * domainname". This field is NULL if "from" clause is not specified. + * (3) "program" which is a program's pathname. + * (4) "is_deleted" is a bool which is true if marked as deleted, false + * otherwise. + * (5) "is_not" is a bool which is true if "no_initialize_domain", false + * otherwise. + * (6) "is_last_name" is a bool which is true if "domainname" is "the last + * component of a domainname", false otherwise. + */ struct tomoyo_domain_initializer_entry { struct list_head list; const struct tomoyo_path_info *domainname; /* This may be NULL */ @@ -34,7 +86,23 @@ struct tomoyo_domain_initializer_entry { bool is_last_name; }; -/* Structure for "keep_domain" and "no_keep_domain" keyword. */ +/* + * tomoyo_domain_keeper_entry is a structure which is used for holding + * "keep_domain" and "no_keep_domain" entries. + * It has following fields. + * + * (1) "list" which is linked to tomoyo_domain_keeper_list . + * (2) "domainname" which is "a domainname" or "the last component of a + * domainname". + * (3) "program" which is a program's pathname. + * This field is NULL if "from" clause is not specified. + * (4) "is_deleted" is a bool which is true if marked as deleted, false + * otherwise. + * (5) "is_not" is a bool which is true if "no_initialize_domain", false + * otherwise. + * (6) "is_last_name" is a bool which is true if "domainname" is "the last + * component of a domainname", false otherwise. + */ struct tomoyo_domain_keeper_entry { struct list_head list; const struct tomoyo_path_info *domainname; @@ -45,7 +113,16 @@ struct tomoyo_domain_keeper_entry { bool is_last_name; }; -/* Structure for "alias" keyword. */ +/* + * tomoyo_alias_entry is a structure which is used for holding "alias" entries. + * It has following fields. + * + * (1) "list" which is linked to tomoyo_alias_list . + * (2) "original_name" which is a dereferenced pathname. + * (3) "aliased_name" which is a symlink's pathname. + * (4) "is_deleted" is a bool which is true if marked as deleted, false + * otherwise. + */ struct tomoyo_alias_entry { struct list_head list; const struct tomoyo_path_info *original_name; @@ -67,14 +144,12 @@ void tomoyo_set_domain_flag(struct tomoyo_domain_info *domain, { /* We need to serialize because this is bitfield operation. */ static DEFINE_SPINLOCK(lock); - /***** CRITICAL SECTION START *****/ spin_lock(&lock); if (!is_delete) domain->flags |= flags; else domain->flags &= ~flags; spin_unlock(&lock); - /***** CRITICAL SECTION END *****/ } /** @@ -94,7 +169,42 @@ const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain) return cp0; } -/* The list for "struct tomoyo_domain_initializer_entry". */ +/* + * 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. + */ static LIST_HEAD(tomoyo_domain_initializer_list); static DECLARE_RWSEM(tomoyo_domain_initializer_list_lock); @@ -135,7 +245,6 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname, saved_program = tomoyo_save_name(program); if (!saved_program) return -ENOMEM; - /***** EXCLUSIVE SECTION START *****/ down_write(&tomoyo_domain_initializer_list_lock); list_for_each_entry(ptr, &tomoyo_domain_initializer_list, list) { if (ptr->is_not != is_not || @@ -161,7 +270,6 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname, error = 0; out: up_write(&tomoyo_domain_initializer_list_lock); - /***** EXCLUSIVE SECTION END *****/ return error; } @@ -193,13 +301,12 @@ bool tomoyo_read_domain_initializer_policy(struct tomoyo_io_buffer *head) from = " from "; domain = ptr->domainname->name; } - if (!tomoyo_io_printf(head, - "%s" TOMOYO_KEYWORD_INITIALIZE_DOMAIN - "%s%s%s\n", no, ptr->program->name, from, - domain)) { - done = false; + done = tomoyo_io_printf(head, + "%s" TOMOYO_KEYWORD_INITIALIZE_DOMAIN + "%s%s%s\n", no, ptr->program->name, + from, domain); + if (!done) break; - } } up_read(&tomoyo_domain_initializer_list_lock); return done; @@ -273,7 +380,44 @@ static bool tomoyo_is_domain_initializer(const struct tomoyo_path_info * return flag; } -/* The list for "struct tomoyo_domain_keeper_entry". */ +/* + * 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". + */ static LIST_HEAD(tomoyo_domain_keeper_list); static DECLARE_RWSEM(tomoyo_domain_keeper_list_lock); @@ -296,7 +440,6 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname, struct tomoyo_domain_keeper_entry *ptr; const struct tomoyo_path_info *saved_domainname; const struct tomoyo_path_info *saved_program = NULL; - static DEFINE_MUTEX(lock); int error = -ENOMEM; bool is_last_name = false; @@ -315,7 +458,6 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname, saved_domainname = tomoyo_save_name(domainname); if (!saved_domainname) return -ENOMEM; - /***** EXCLUSIVE SECTION START *****/ down_write(&tomoyo_domain_keeper_list_lock); list_for_each_entry(ptr, &tomoyo_domain_keeper_list, list) { if (ptr->is_not != is_not || @@ -341,7 +483,6 @@ static int tomoyo_update_domain_keeper_entry(const char *domainname, error = 0; out: up_write(&tomoyo_domain_keeper_list_lock); - /***** EXCLUSIVE SECTION END *****/ return error; } @@ -394,13 +535,12 @@ bool tomoyo_read_domain_keeper_policy(struct tomoyo_io_buffer *head) from = " from "; program = ptr->program->name; } - if (!tomoyo_io_printf(head, - "%s" TOMOYO_KEYWORD_KEEP_DOMAIN - "%s%s%s\n", no, program, from, - ptr->domainname->name)) { - done = false; + done = tomoyo_io_printf(head, + "%s" TOMOYO_KEYWORD_KEEP_DOMAIN + "%s%s%s\n", no, program, from, + ptr->domainname->name); + if (!done) break; - } } up_read(&tomoyo_domain_keeper_list_lock); return done; @@ -446,7 +586,36 @@ static bool tomoyo_is_domain_keeper(const struct tomoyo_path_info *domainname, return flag; } -/* The list for "struct tomoyo_alias_entry". */ +/* + * 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 . + */ static LIST_HEAD(tomoyo_alias_list); static DECLARE_RWSEM(tomoyo_alias_list_lock); @@ -476,7 +645,6 @@ static int tomoyo_update_alias_entry(const char *original_name, saved_aliased_name = tomoyo_save_name(aliased_name); if (!saved_original_name || !saved_aliased_name) return -ENOMEM; - /***** EXCLUSIVE SECTION START *****/ down_write(&tomoyo_alias_list_lock); list_for_each_entry(ptr, &tomoyo_alias_list, list) { if (ptr->original_name != saved_original_name || @@ -499,7 +667,6 @@ static int tomoyo_update_alias_entry(const char *original_name, error = 0; out: up_write(&tomoyo_alias_list_lock); - /***** EXCLUSIVE SECTION END *****/ return error; } @@ -522,12 +689,11 @@ bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head) ptr = list_entry(pos, struct tomoyo_alias_entry, list); if (ptr->is_deleted) continue; - if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_ALIAS "%s %s\n", - ptr->original_name->name, - ptr->aliased_name->name)) { - done = false; + done = tomoyo_io_printf(head, TOMOYO_KEYWORD_ALIAS "%s %s\n", + ptr->original_name->name, + ptr->aliased_name->name); + if (!done) break; - } } up_read(&tomoyo_alias_list_lock); return done; @@ -567,7 +733,6 @@ int tomoyo_delete_domain(char *domainname) name.name = domainname; tomoyo_fill_path_info(&name); - /***** EXCLUSIVE SECTION START *****/ down_write(&tomoyo_domain_list_lock); /* Is there an active domain? */ list_for_each_entry(domain, &tomoyo_domain_list, list) { @@ -581,7 +746,6 @@ int tomoyo_delete_domain(char *domainname) break; } up_write(&tomoyo_domain_list_lock); - /***** EXCLUSIVE SECTION END *****/ return 0; } @@ -600,7 +764,6 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * struct tomoyo_domain_info *domain = NULL; const struct tomoyo_path_info *saved_domainname; - /***** EXCLUSIVE SECTION START *****/ down_write(&tomoyo_domain_list_lock); domain = tomoyo_find_domain(domainname); if (domain) @@ -619,7 +782,6 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * domain->domainname != saved_domainname) continue; flag = false; - /***** CRITICAL SECTION START *****/ read_lock(&tasklist_lock); for_each_process(p) { if (tomoyo_real_domain(p) != domain) @@ -628,7 +790,6 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * break; } read_unlock(&tasklist_lock); - /***** CRITICAL SECTION END *****/ if (flag) continue; list_for_each_entry(ptr, &domain->acl_info_list, list) { @@ -651,7 +812,6 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * } out: up_write(&tomoyo_domain_list_lock); - /***** EXCLUSIVE SECTION END *****/ return domain; } @@ -739,7 +899,7 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm, } /* Check execute permission. */ - retval = tomoyo_check_exec_perm(old_domain, &r, tmp); + retval = tomoyo_check_exec_perm(old_domain, &r); if (retval < 0) goto out; |