TOMOYO: Allow using argv[]/envp[] of execve() as conditions.
[deliverable/linux.git] / security / tomoyo / condition.c
index 790b9872cc378938e7a9841ef6e401558cdd181a..8a05f71eaf6744a71116f4afe39f9a4a8fb23074 100644 (file)
 /* List of "struct tomoyo_condition". */
 LIST_HEAD(tomoyo_condition_list);
 
+/**
+ * tomoyo_argv - Check argv[] in "struct linux_binbrm".
+ *
+ * @index:   Index number of @arg_ptr.
+ * @arg_ptr: Contents of argv[@index].
+ * @argc:    Length of @argv.
+ * @argv:    Pointer to "struct tomoyo_argv".
+ * @checked: Set to true if @argv[@index] was found.
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_argv(const unsigned int index, const char *arg_ptr,
+                       const int argc, const struct tomoyo_argv *argv,
+                       u8 *checked)
+{
+       int i;
+       struct tomoyo_path_info arg;
+       arg.name = arg_ptr;
+       for (i = 0; i < argc; argv++, checked++, i++) {
+               bool result;
+               if (index != argv->index)
+                       continue;
+               *checked = 1;
+               tomoyo_fill_path_info(&arg);
+               result = tomoyo_path_matches_pattern(&arg, argv->value);
+               if (argv->is_not)
+                       result = !result;
+               if (!result)
+                       return false;
+       }
+       return true;
+}
+
+/**
+ * tomoyo_envp - Check envp[] in "struct linux_binbrm".
+ *
+ * @env_name:  The name of environment variable.
+ * @env_value: The value of environment variable.
+ * @envc:      Length of @envp.
+ * @envp:      Pointer to "struct tomoyo_envp".
+ * @checked:   Set to true if @envp[@env_name] was found.
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_envp(const char *env_name, const char *env_value,
+                       const int envc, const struct tomoyo_envp *envp,
+                       u8 *checked)
+{
+       int i;
+       struct tomoyo_path_info name;
+       struct tomoyo_path_info value;
+       name.name = env_name;
+       tomoyo_fill_path_info(&name);
+       value.name = env_value;
+       tomoyo_fill_path_info(&value);
+       for (i = 0; i < envc; envp++, checked++, i++) {
+               bool result;
+               if (!tomoyo_path_matches_pattern(&name, envp->name))
+                       continue;
+               *checked = 1;
+               if (envp->value) {
+                       result = tomoyo_path_matches_pattern(&value,
+                                                            envp->value);
+                       if (envp->is_not)
+                               result = !result;
+               } else {
+                       result = true;
+                       if (!envp->is_not)
+                               result = !result;
+               }
+               if (!result)
+                       return false;
+       }
+       return true;
+}
+
+/**
+ * tomoyo_scan_bprm - Scan "struct linux_binprm".
+ *
+ * @ee:   Pointer to "struct tomoyo_execve".
+ * @argc: Length of @argc.
+ * @argv: Pointer to "struct tomoyo_argv".
+ * @envc: Length of @envp.
+ * @envp: Poiner to "struct tomoyo_envp".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_scan_bprm(struct tomoyo_execve *ee,
+                            const u16 argc, const struct tomoyo_argv *argv,
+                            const u16 envc, const struct tomoyo_envp *envp)
+{
+       struct linux_binprm *bprm = ee->bprm;
+       struct tomoyo_page_dump *dump = &ee->dump;
+       char *arg_ptr = ee->tmp;
+       int arg_len = 0;
+       unsigned long pos = bprm->p;
+       int offset = pos % PAGE_SIZE;
+       int argv_count = bprm->argc;
+       int envp_count = bprm->envc;
+       bool result = true;
+       u8 local_checked[32];
+       u8 *checked;
+       if (argc + envc <= sizeof(local_checked)) {
+               checked = local_checked;
+               memset(local_checked, 0, sizeof(local_checked));
+       } else {
+               checked = kzalloc(argc + envc, GFP_NOFS);
+               if (!checked)
+                       return false;
+       }
+       while (argv_count || envp_count) {
+               if (!tomoyo_dump_page(bprm, pos, dump)) {
+                       result = false;
+                       goto out;
+               }
+               pos += PAGE_SIZE - offset;
+               while (offset < PAGE_SIZE) {
+                       /* Read. */
+                       const char *kaddr = dump->data;
+                       const unsigned char c = kaddr[offset++];
+                       if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
+                               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;
+                       /* Check. */
+                       if (argv_count) {
+                               if (!tomoyo_argv(bprm->argc - argv_count,
+                                                arg_ptr, argc, argv,
+                                                checked)) {
+                                       result = false;
+                                       break;
+                               }
+                               argv_count--;
+                       } else if (envp_count) {
+                               char *cp = strchr(arg_ptr, '=');
+                               if (cp) {
+                                       *cp = '\0';
+                                       if (!tomoyo_envp(arg_ptr, cp + 1,
+                                                        envc, envp,
+                                                        checked + argc)) {
+                                               result = false;
+                                               break;
+                                       }
+                               }
+                               envp_count--;
+                       } else {
+                               break;
+                       }
+                       arg_len = 0;
+               }
+               offset = 0;
+               if (!result)
+                       break;
+       }
+out:
+       if (result) {
+               int i;
+               /* Check not-yet-checked entries. */
+               for (i = 0; i < argc; i++) {
+                       if (checked[i])
+                               continue;
+                       /*
+                        * Return true only if all unchecked indexes in
+                        * bprm->argv[] are not matched.
+                        */
+                       if (argv[i].is_not)
+                               continue;
+                       result = false;
+                       break;
+               }
+               for (i = 0; i < envc; envp++, i++) {
+                       if (checked[argc + i])
+                               continue;
+                       /*
+                        * Return true only if all unchecked environ variables
+                        * in bprm->envp[] are either undefined or not matched.
+                        */
+                       if ((!envp->value && !envp->is_not) ||
+                           (envp->value && envp->is_not))
+                               continue;
+                       result = false;
+                       break;
+               }
+       }
+       if (checked != local_checked)
+               kfree(checked);
+       return result;
+}
+
 /**
  * tomoyo_scan_exec_realpath - Check "exec.realpath" parameter of "struct tomoyo_condition".
  *
@@ -72,6 +275,64 @@ static bool tomoyo_parse_name_union_quoted(struct tomoyo_acl_param *param,
        return ptr->filename != NULL;
 }
 
+/**
+ * tomoyo_parse_argv - Parse an argv[] condition part.
+ *
+ * @left:  Lefthand value.
+ * @right: Righthand value.
+ * @argv:  Pointer to "struct tomoyo_argv".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_parse_argv(char *left, char *right,
+                             struct tomoyo_argv *argv)
+{
+       if (tomoyo_parse_ulong(&argv->index, &left) !=
+           TOMOYO_VALUE_TYPE_DECIMAL || *left++ != ']' || *left)
+               return false;
+       argv->value = tomoyo_get_dqword(right);
+       return argv->value != NULL;
+}
+
+/**
+ * tomoyo_parse_envp - Parse an envp[] condition part.
+ *
+ * @left:  Lefthand value.
+ * @right: Righthand value.
+ * @envp:  Pointer to "struct tomoyo_envp".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_parse_envp(char *left, char *right,
+                             struct tomoyo_envp *envp)
+{
+       const struct tomoyo_path_info *name;
+       const struct tomoyo_path_info *value;
+       char *cp = left + strlen(left) - 1;
+       if (*cp-- != ']' || *cp != '"')
+               goto out;
+       *cp = '\0';
+       if (!tomoyo_correct_word(left))
+               goto out;
+       name = tomoyo_get_name(left);
+       if (!name)
+               goto out;
+       if (!strcmp(right, "NULL")) {
+               value = NULL;
+       } else {
+               value = tomoyo_get_dqword(right);
+               if (!value) {
+                       tomoyo_put_name(name);
+                       goto out;
+               }
+       }
+       envp->name = name;
+       envp->value = value;
+       return true;
+out:
+       return false;
+}
+
 /**
  * tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry.
  *
@@ -86,6 +347,7 @@ static inline bool tomoyo_same_condition(const struct tomoyo_condition *a,
        return a->size == b->size && a->condc == b->condc &&
                a->numbers_count == b->numbers_count &&
                a->names_count == b->names_count &&
+               a->argc == b->argc && a->envc == b->envc &&
                !memcmp(a + 1, b + 1, a->size - sizeof(*a));
 }
 
@@ -178,6 +440,8 @@ struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param)
        struct tomoyo_condition_element *condp = NULL;
        struct tomoyo_number_union *numbers_p = NULL;
        struct tomoyo_name_union *names_p = NULL;
+       struct tomoyo_argv *argv = NULL;
+       struct tomoyo_envp *envp = NULL;
        struct tomoyo_condition e = { };
        char * const start_of_string = param->data;
        char * const end_of_string = start_of_string + strlen(start_of_string);
@@ -222,6 +486,36 @@ rerun:
                        goto out;
                dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word,
                        is_not ? "!" : "", right_word);
+               if (!strncmp(left_word, "exec.argv[", 10)) {
+                       if (!argv) {
+                               e.argc++;
+                               e.condc++;
+                       } else {
+                               e.argc--;
+                               e.condc--;
+                               left = TOMOYO_ARGV_ENTRY;
+                               argv->is_not = is_not;
+                               if (!tomoyo_parse_argv(left_word + 10,
+                                                      right_word, argv++))
+                                       goto out;
+                       }
+                       goto store_value;
+               }
+               if (!strncmp(left_word, "exec.envp[\"", 11)) {
+                       if (!envp) {
+                               e.envc++;
+                               e.condc++;
+                       } else {
+                               e.envc--;
+                               e.condc--;
+                               left = TOMOYO_ENVP_ENTRY;
+                               envp->is_not = is_not;
+                               if (!tomoyo_parse_envp(left_word + 11,
+                                                      right_word, envp++))
+                                       goto out;
+                       }
+                       goto store_value;
+               }
                left = tomoyo_condition_type(left_word);
                dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word,
                        left);
@@ -283,16 +577,20 @@ store_value:
                        condp->equals);
                condp++;
        }
-       dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u\n",
-               __LINE__, e.condc, e.numbers_count, e.names_count);
+       dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u ac=%u ec=%u\n",
+               __LINE__, e.condc, e.numbers_count, e.names_count, e.argc,
+               e.envc);
        if (entry) {
-               BUG_ON(e.names_count | e.numbers_count | e.condc);
+               BUG_ON(e.names_count | e.numbers_count | e.argc | e.envc |
+                      e.condc);
                return tomoyo_commit_condition(entry);
        }
        e.size = sizeof(*entry)
                + e.condc * sizeof(struct tomoyo_condition_element)
                + e.numbers_count * sizeof(struct tomoyo_number_union)
-               + e.names_count * sizeof(struct tomoyo_name_union);
+               + e.names_count * sizeof(struct tomoyo_name_union)
+               + e.argc * sizeof(struct tomoyo_argv)
+               + e.envc * sizeof(struct tomoyo_envp);
        entry = kzalloc(e.size, GFP_NOFS);
        if (!entry)
                return NULL;
@@ -300,6 +598,8 @@ store_value:
        condp = (struct tomoyo_condition_element *) (entry + 1);
        numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
        names_p = (struct tomoyo_name_union *) (numbers_p + e.numbers_count);
+       argv = (struct tomoyo_argv *) (names_p + e.names_count);
+       envp = (struct tomoyo_envp *) (argv + e.argc);
        {
                bool flag = false;
                for (pos = start_of_string; pos < end_of_string; pos++) {
@@ -391,16 +691,29 @@ bool tomoyo_condition(struct tomoyo_request_info *r,
        const struct tomoyo_condition_element *condp;
        const struct tomoyo_number_union *numbers_p;
        const struct tomoyo_name_union *names_p;
+       const struct tomoyo_argv *argv;
+       const struct tomoyo_envp *envp;
        struct tomoyo_obj_info *obj;
        u16 condc;
+       u16 argc;
+       u16 envc;
+       struct linux_binprm *bprm = NULL;
        if (!cond)
                return true;
        condc = cond->condc;
+       argc = cond->argc;
+       envc = cond->envc;
        obj = r->obj;
+       if (r->ee)
+               bprm = r->ee->bprm;
+       if (!bprm && (argc || envc))
+               return false;
        condp = (struct tomoyo_condition_element *) (cond + 1);
        numbers_p = (const struct tomoyo_number_union *) (condp + condc);
        names_p = (const struct tomoyo_name_union *)
                (numbers_p + cond->numbers_count);
+       argv = (const struct tomoyo_argv *) (names_p + cond->names_count);
+       envp = (const struct tomoyo_envp *) (argv + argc);
        for (i = 0; i < condc; i++) {
                const bool match = condp->equals;
                const u8 left = condp->left;
@@ -408,6 +721,9 @@ bool tomoyo_condition(struct tomoyo_request_info *r,
                bool is_bitop[2] = { false, false };
                u8 j;
                condp++;
+               /* Check argv[] and envp[] later. */
+               if (left == TOMOYO_ARGV_ENTRY || left == TOMOYO_ENVP_ENTRY)
+                       continue;
                /* Check string expressions. */
                if (right == TOMOYO_NAME_UNION) {
                        const struct tomoyo_name_union *ptr = names_p++;
@@ -524,6 +840,16 @@ bool tomoyo_condition(struct tomoyo_request_info *r,
                        case TOMOYO_MODE_OTHERS_EXECUTE:
                                value = S_IXOTH;
                                break;
+                       case TOMOYO_EXEC_ARGC:
+                               if (!bprm)
+                                       goto out;
+                               value = bprm->argc;
+                               break;
+                       case TOMOYO_EXEC_ENVC:
+                               if (!bprm)
+                                       goto out;
+                               value = bprm->envc;
+                               break;
                        case TOMOYO_NUMBER_UNION:
                                /* Fetch values later. */
                                break;
@@ -702,5 +1028,8 @@ bool tomoyo_condition(struct tomoyo_request_info *r,
 out:
                return false;
        }
+       /* Check argv[] and envp[] now. */
+       if (r->ee && (argc || envc))
+               return tomoyo_scan_bprm(r->ee, argc, argv, envc, envp);
        return true;
 }
This page took 0.034693 seconds and 5 git commands to generate.