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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2011-09-10 15:22:48 +0900
committerJames Morris <jmorris@namei.org>2011-09-14 08:27:05 +1000
commitd58e0da854376841ac99defeb117a83f086715c6 (patch)
treeb6e37d1030180680a7801ecb295d8d3990930375 /security/tomoyo
parent5dbe3040c74eef18e66951347eda05b153e69328 (diff)
downloadvexpress-lsk-d58e0da854376841ac99defeb117a83f086715c6.tar.gz
TOMOYO: Add environment variable name restriction support.
This patch adds support for checking environment variable's names. Although TOMOYO already provides ability to check argv[]/envp[] passed to execve() requests, file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]="bar" will reject execution of /bin/sh if environment variable LD_LIBRARY_PATH is not defined. To grant execution of /bin/sh if LD_LIBRARY_PATH is not defined, administrators have to specify like file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]="/system/lib" file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]=NULL . Since there are many environment variables whereas conditional checks are applied as "&&", it is difficult to cover all combinations. Therefore, this patch supports conditional checks that are applied as "||", by specifying like file execute /bin/sh misc env LD_LIBRARY_PATH exec.envp["LD_LIBRARY_PATH"]="/system/lib" which means "grant execution of /bin/sh if environment variable is not defined or is defined and its value is /system/lib". Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/tomoyo')
-rw-r--r--security/tomoyo/Makefile2
-rw-r--r--security/tomoyo/common.c20
-rw-r--r--security/tomoyo/common.h14
-rw-r--r--security/tomoyo/domain.c95
-rw-r--r--security/tomoyo/environ.c122
-rw-r--r--security/tomoyo/gc.c9
-rw-r--r--security/tomoyo/util.c14
7 files changed, 266 insertions, 10 deletions
diff --git a/security/tomoyo/Makefile b/security/tomoyo/Makefile
index 95278b71fc2..f7ade960f6c 100644
--- a/security/tomoyo/Makefile
+++ b/security/tomoyo/Makefile
@@ -1,4 +1,4 @@
-obj-y = audit.o common.o condition.o domain.o file.o gc.o group.o load_policy.o memory.o mount.o realpath.o securityfs_if.o tomoyo.o util.o
+obj-y = audit.o common.o condition.o domain.o environ.o file.o gc.o group.o load_policy.o memory.o mount.o realpath.o securityfs_if.o tomoyo.o util.o
$(obj)/policy/profile.conf:
@mkdir -p $(obj)/policy/
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index c8439cf2a44..d116e1ece3e 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -20,6 +20,7 @@ const char * const tomoyo_mode[TOMOYO_CONFIG_MAX_MODE] = {
/* String table for /sys/kernel/security/tomoyo/profile */
const char * const tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
+ TOMOYO_MAX_MAC_CATEGORY_INDEX] = {
+ /* CONFIG::file group */
[TOMOYO_MAC_FILE_EXECUTE] = "execute",
[TOMOYO_MAC_FILE_OPEN] = "open",
[TOMOYO_MAC_FILE_CREATE] = "create",
@@ -43,7 +44,11 @@ const char * const tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
[TOMOYO_MAC_FILE_MOUNT] = "mount",
[TOMOYO_MAC_FILE_UMOUNT] = "unmount",
[TOMOYO_MAC_FILE_PIVOT_ROOT] = "pivot_root",
+ /* CONFIG::misc group */
+ [TOMOYO_MAC_ENVIRON] = "env",
+ /* CONFIG group */
[TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_FILE] = "file",
+ [TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_MISC] = "misc",
};
/* String table for conditions. */
@@ -133,7 +138,8 @@ const char * const tomoyo_path_keyword[TOMOYO_MAX_PATH_OPERATION] = {
/* String table for categories. */
static const char * const tomoyo_category_keywords
[TOMOYO_MAX_MAC_CATEGORY_INDEX] = {
- [TOMOYO_MAC_CATEGORY_FILE] = "file",
+ [TOMOYO_MAC_CATEGORY_FILE] = "file",
+ [TOMOYO_MAC_CATEGORY_MISC] = "misc",
};
/* Permit policy management by non-root user? */
@@ -1036,11 +1042,13 @@ static int tomoyo_write_domain2(struct tomoyo_policy_namespace *ns,
static const struct {
const char *keyword;
int (*write) (struct tomoyo_acl_param *);
- } tomoyo_callback[1] = {
+ } tomoyo_callback[2] = {
{ "file ", tomoyo_write_file },
+ { "misc ", tomoyo_write_misc },
};
u8 i;
- for (i = 0; i < 1; i++) {
+
+ for (i = 0; i < ARRAY_SIZE(tomoyo_callback); i++) {
if (!tomoyo_str_starts(&param.data,
tomoyo_callback[i].keyword))
continue;
@@ -1375,6 +1383,12 @@ static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
tomoyo_print_name_union(head, &ptr->dir_name);
tomoyo_print_name_union(head, &ptr->fs_type);
tomoyo_print_number_union(head, &ptr->flags);
+ } else if (acl_type == TOMOYO_TYPE_ENV_ACL) {
+ struct tomoyo_env_acl *ptr =
+ container_of(acl, typeof(*ptr), head);
+
+ tomoyo_set_group(head, "misc env ");
+ tomoyo_set_string(head, ptr->env->name);
}
if (acl->cond) {
head->r.print_cond_part = true;
diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h
index f7fbaa66e44..63720a328ed 100644
--- a/security/tomoyo/common.h
+++ b/security/tomoyo/common.h
@@ -196,6 +196,7 @@ enum tomoyo_acl_entry_type_index {
TOMOYO_TYPE_PATH_NUMBER_ACL,
TOMOYO_TYPE_MKDEV_ACL,
TOMOYO_TYPE_MOUNT_ACL,
+ TOMOYO_TYPE_ENV_ACL,
};
/* Index numbers for access controls with one pathname. */
@@ -300,12 +301,14 @@ enum tomoyo_mac_index {
TOMOYO_MAC_FILE_MOUNT,
TOMOYO_MAC_FILE_UMOUNT,
TOMOYO_MAC_FILE_PIVOT_ROOT,
+ TOMOYO_MAC_ENVIRON,
TOMOYO_MAX_MAC_INDEX
};
/* Index numbers for category of functionality. */
enum tomoyo_mac_category_index {
TOMOYO_MAC_CATEGORY_FILE,
+ TOMOYO_MAC_CATEGORY_MISC,
TOMOYO_MAX_MAC_CATEGORY_INDEX
};
@@ -397,6 +400,9 @@ struct tomoyo_request_info {
u8 operation;
} path_number;
struct {
+ const struct tomoyo_path_info *name;
+ } environ;
+ struct {
const struct tomoyo_path_info *type;
const struct tomoyo_path_info *dir;
const struct tomoyo_path_info *dev;
@@ -638,6 +644,12 @@ struct tomoyo_mount_acl {
struct tomoyo_number_union flags;
};
+/* Structure for "misc env" directive in domain policy. */
+struct tomoyo_env_acl {
+ struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_ENV_ACL */
+ const struct tomoyo_path_info *env; /* environment variable */
+};
+
/* Structure for holding a line from /sys/kernel/security/tomoyo/ interface. */
struct tomoyo_acl_param {
char *data;
@@ -820,6 +832,7 @@ const struct tomoyo_path_info *tomoyo_path_matches_group
int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
struct path *path, const int flag);
int tomoyo_close_control(struct tomoyo_io_buffer *head);
+int tomoyo_env_perm(struct tomoyo_request_info *r, const char *env);
int tomoyo_find_next_domain(struct linux_binprm *bprm);
int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
const u8 index);
@@ -860,6 +873,7 @@ int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
int tomoyo_write_aggregator(struct tomoyo_acl_param *param);
int tomoyo_write_file(struct tomoyo_acl_param *param);
int tomoyo_write_group(struct tomoyo_acl_param *param, const u8 type);
+int tomoyo_write_misc(struct tomoyo_acl_param *param);
int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
const u8 type);
ssize_t tomoyo_read_control(struct tomoyo_io_buffer *head, char __user *buffer,
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index cd0f92d88bb..5931fb1c04d 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -563,6 +563,92 @@ out:
}
/**
+ * tomoyo_environ - Check permission for environment variable names.
+ *
+ * @ee: Pointer to "struct tomoyo_execve".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int tomoyo_environ(struct tomoyo_execve *ee)
+{
+ struct tomoyo_request_info *r = &ee->r;
+ struct linux_binprm *bprm = ee->bprm;
+ /* env_page.data is allocated by tomoyo_dump_page(). */
+ struct tomoyo_page_dump env_page = { };
+ char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
+ int arg_len = 0;
+ unsigned long pos = bprm->p;
+ int offset = pos % PAGE_SIZE;
+ int argv_count = bprm->argc;
+ int envp_count = bprm->envc;
+ int error = -ENOMEM;
+
+ ee->r.type = TOMOYO_MAC_ENVIRON;
+ ee->r.profile = r->domain->profile;
+ ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
+ TOMOYO_MAC_ENVIRON);
+ if (!r->mode || !envp_count)
+ return 0;
+ arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
+ if (!arg_ptr)
+ goto out;
+ while (error == -ENOMEM) {
+ if (!tomoyo_dump_page(bprm, pos, &env_page))
+ goto out;
+ pos += PAGE_SIZE - offset;
+ /* Read. */
+ while (argv_count && offset < PAGE_SIZE) {
+ if (!env_page.data[offset++])
+ argv_count--;
+ }
+ if (argv_count) {
+ offset = 0;
+ continue;
+ }
+ while (offset < PAGE_SIZE) {
+ const unsigned char c = env_page.data[offset++];
+
+ if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
+ if (c == '=') {
+ arg_ptr[arg_len++] = '\0';
+ } else if (c == '\\') {
+ arg_ptr[arg_len++] = '\\';
+ arg_ptr[arg_len++] = '\\';
+ } else if (c > ' ' && c < 127) {
+ arg_ptr[arg_len++] = c;
+ } else {
+ arg_ptr[arg_len++] = '\\';
+ arg_ptr[arg_len++] = (c >> 6) + '0';
+ arg_ptr[arg_len++]
+ = ((c >> 3) & 7) + '0';
+ arg_ptr[arg_len++] = (c & 7) + '0';
+ }
+ } else {
+ arg_ptr[arg_len] = '\0';
+ }
+ if (c)
+ continue;
+ if (tomoyo_env_perm(r, arg_ptr)) {
+ error = -EPERM;
+ break;
+ }
+ if (!--envp_count) {
+ error = 0;
+ break;
+ }
+ arg_len = 0;
+ }
+ offset = 0;
+ }
+out:
+ if (r->mode != TOMOYO_CONFIG_ENFORCING)
+ error = 0;
+ kfree(env_page.data);
+ kfree(arg_ptr);
+ return error;
+}
+
+/**
* tomoyo_find_next_domain - Find a domain.
*
* @bprm: Pointer to "struct linux_binprm".
@@ -581,6 +667,7 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
bool reject_on_transition_failure = false;
struct tomoyo_path_info rn = { }; /* real name */
struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
+
if (!ee)
return -ENOMEM;
ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
@@ -713,6 +800,10 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
bprm->cred->security = domain;
if (need_kfree)
kfree(rn.name);
+ if (!retval) {
+ ee->r.domain = domain;
+ retval = tomoyo_environ(ee);
+ }
kfree(ee->tmp);
kfree(ee->dump.data);
kfree(ee);
@@ -732,7 +823,8 @@ bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
struct tomoyo_page_dump *dump)
{
struct page *page;
- /* dump->data is released by tomoyo_finish_execve(). */
+
+ /* dump->data is released by tomoyo_find_next_domain(). */
if (!dump->data) {
dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
if (!dump->data)
@@ -753,6 +845,7 @@ bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
* So do I.
*/
char *kaddr = kmap_atomic(page, KM_USER0);
+
dump->page = page;
memcpy(dump->data + offset, kaddr + offset,
PAGE_SIZE - offset);
diff --git a/security/tomoyo/environ.c b/security/tomoyo/environ.c
new file mode 100644
index 00000000000..ad4c6e18a43
--- /dev/null
+++ b/security/tomoyo/environ.c
@@ -0,0 +1,122 @@
+/*
+ * security/tomoyo/environ.c
+ *
+ * Copyright (C) 2005-2011 NTT DATA CORPORATION
+ */
+
+#include "common.h"
+
+/**
+ * tomoyo_check_env_acl - Check permission for environment variable's name.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ * @ptr: Pointer to "struct tomoyo_acl_info".
+ *
+ * Returns true if granted, false otherwise.
+ */
+static bool tomoyo_check_env_acl(struct tomoyo_request_info *r,
+ const struct tomoyo_acl_info *ptr)
+{
+ const struct tomoyo_env_acl *acl =
+ container_of(ptr, typeof(*acl), head);
+
+ return tomoyo_path_matches_pattern(r->param.environ.name, acl->env);
+}
+
+/**
+ * tomoyo_audit_env_log - Audit environment variable name log.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+static int tomoyo_audit_env_log(struct tomoyo_request_info *r)
+{
+ return tomoyo_supervisor(r, "misc env %s\n",
+ r->param.environ.name->name);
+}
+
+/**
+ * tomoyo_env_perm - Check permission for environment variable's name.
+ *
+ * @r: Pointer to "struct tomoyo_request_info".
+ * @env: The name of environment variable.
+ *
+ * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+int tomoyo_env_perm(struct tomoyo_request_info *r, const char *env)
+{
+ struct tomoyo_path_info environ;
+ int error;
+
+ if (!env || !*env)
+ return 0;
+ environ.name = env;
+ tomoyo_fill_path_info(&environ);
+ r->param_type = TOMOYO_TYPE_ENV_ACL;
+ r->param.environ.name = &environ;
+ do {
+ tomoyo_check_acl(r, tomoyo_check_env_acl);
+ error = tomoyo_audit_env_log(r);
+ } while (error == TOMOYO_RETRY_REQUEST);
+ return error;
+}
+
+/**
+ * tomoyo_same_env_acl - Check for duplicated "struct tomoyo_env_acl" entry.
+ *
+ * @a: Pointer to "struct tomoyo_acl_info".
+ * @b: Pointer to "struct tomoyo_acl_info".
+ *
+ * Returns true if @a == @b, false otherwise.
+ */
+static bool tomoyo_same_env_acl(const struct tomoyo_acl_info *a,
+ const struct tomoyo_acl_info *b)
+{
+ const struct tomoyo_env_acl *p1 = container_of(a, typeof(*p1), head);
+ const struct tomoyo_env_acl *p2 = container_of(b, typeof(*p2), head);
+
+ return p1->env == p2->env;
+}
+
+/**
+ * tomoyo_write_env - Write "struct tomoyo_env_acl" list.
+ *
+ * @param: Pointer to "struct tomoyo_acl_param".
+ *
+ * Returns 0 on success, negative value otherwise.
+ *
+ * Caller holds tomoyo_read_lock().
+ */
+static int tomoyo_write_env(struct tomoyo_acl_param *param)
+{
+ struct tomoyo_env_acl e = { .head.type = TOMOYO_TYPE_ENV_ACL };
+ int error = -ENOMEM;
+ const char *data = tomoyo_read_token(param);
+
+ if (!tomoyo_correct_word(data) || strchr(data, '='))
+ return -EINVAL;
+ e.env = tomoyo_get_name(data);
+ if (!e.env)
+ return error;
+ error = tomoyo_update_domain(&e.head, sizeof(e), param,
+ tomoyo_same_env_acl, NULL);
+ tomoyo_put_name(e.env);
+ return error;
+}
+
+/**
+ * tomoyo_write_misc - Update environment variable list.
+ *
+ * @param: Pointer to "struct tomoyo_acl_param".
+ *
+ * Returns 0 on success, negative value otherwise.
+ */
+int tomoyo_write_misc(struct tomoyo_acl_param *param)
+{
+ if (tomoyo_str_starts(&param->data, "env "))
+ return tomoyo_write_env(param);
+ return -EINVAL;
+}
diff --git a/security/tomoyo/gc.c b/security/tomoyo/gc.c
index 5295b5caaa2..818b0799811 100644
--- a/security/tomoyo/gc.c
+++ b/security/tomoyo/gc.c
@@ -36,6 +36,7 @@ static const u8 tomoyo_acl_size[] = {
[TOMOYO_TYPE_PATH_NUMBER_ACL] = sizeof(struct tomoyo_path_number_acl),
[TOMOYO_TYPE_MKDEV_ACL] = sizeof(struct tomoyo_mkdev_acl),
[TOMOYO_TYPE_MOUNT_ACL] = sizeof(struct tomoyo_mount_acl),
+ [TOMOYO_TYPE_ENV_ACL] = sizeof(struct tomoyo_env_acl),
};
/**
@@ -293,6 +294,14 @@ static void tomoyo_del_acl(struct list_head *element)
tomoyo_put_number_union(&entry->flags);
}
break;
+ case TOMOYO_TYPE_ENV_ACL:
+ {
+ struct tomoyo_env_acl *entry =
+ container_of(acl, typeof(*entry), head);
+
+ tomoyo_put_name(entry->env);
+ }
+ break;
}
}
diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c
index 6a4195a4b93..cb7d507b631 100644
--- a/security/tomoyo/util.c
+++ b/security/tomoyo/util.c
@@ -42,6 +42,8 @@ const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
[TOMOYO_MAC_FILE_MOUNT] = TOMOYO_MAC_CATEGORY_FILE,
[TOMOYO_MAC_FILE_UMOUNT] = TOMOYO_MAC_CATEGORY_FILE,
[TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
+ /* CONFIG::misc group */
+ [TOMOYO_MAC_ENVIRON] = TOMOYO_MAC_CATEGORY_MISC,
};
/**
@@ -920,15 +922,17 @@ int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
const u8 index)
{
u8 mode;
- const u8 category = TOMOYO_MAC_CATEGORY_FILE;
+ struct tomoyo_profile *p;
+
if (!tomoyo_policy_loaded)
return TOMOYO_CONFIG_DISABLED;
- mode = tomoyo_profile(ns, profile)->config[index];
+ p = tomoyo_profile(ns, profile);
+ mode = p->config[index];
if (mode == TOMOYO_CONFIG_USE_DEFAULT)
- mode = tomoyo_profile(ns, profile)->config
- [category + TOMOYO_MAX_MAC_INDEX];
+ mode = p->config[tomoyo_index2category[index]
+ + TOMOYO_MAX_MAC_INDEX];
if (mode == TOMOYO_CONFIG_USE_DEFAULT)
- mode = tomoyo_profile(ns, profile)->default_config;
+ mode = p->default_config;
return mode & 3;
}