TOMOYO: Allow using executable's realpath and symlink's target as conditions.
This patch adds support for permission checks using executable file's realpath
upon execve() and symlink's target upon symlink(). Hooks are in the last patch
of this pathset.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index ec02d2a..69d6b59 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -79,6 +79,8 @@
[TOMOYO_MODE_OTHERS_READ] = "others_read",
[TOMOYO_MODE_OTHERS_WRITE] = "others_write",
[TOMOYO_MODE_OTHERS_EXECUTE] = "others_execute",
+ [TOMOYO_EXEC_REALPATH] = "exec.realpath",
+ [TOMOYO_SYMLINK_TARGET] = "symlink.target",
[TOMOYO_PATH1_UID] = "path1.uid",
[TOMOYO_PATH1_GID] = "path1.gid",
[TOMOYO_PATH1_INO] = "path1.ino",
@@ -353,6 +355,27 @@
}
/**
+ * tomoyo_print_name_union_quoted - Print a tomoyo_name_union with a quote.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ * @ptr: Pointer to "struct tomoyo_name_union".
+ *
+ * Returns nothing.
+ */
+static void tomoyo_print_name_union_quoted(struct tomoyo_io_buffer *head,
+ const struct tomoyo_name_union *ptr)
+{
+ if (ptr->group) {
+ tomoyo_set_string(head, "@");
+ tomoyo_set_string(head, ptr->group->group_name->name);
+ } else {
+ tomoyo_set_string(head, "\"");
+ tomoyo_set_string(head, ptr->filename->name);
+ tomoyo_set_string(head, "\"");
+ }
+}
+
+/**
* tomoyo_print_number_union_nospace - Print a tomoyo_number_union without a space.
*
* @head: Pointer to "struct tomoyo_io_buffer".
@@ -1101,6 +1124,9 @@
(typeof(condp)) (cond + 1);
const struct tomoyo_number_union *numbers_p =
(typeof(numbers_p)) (condp + condc);
+ const struct tomoyo_name_union *names_p =
+ (typeof(names_p))
+ (numbers_p + cond->numbers_count);
u16 skip;
for (skip = 0; skip < head->r.cond_index; skip++) {
const u8 left = condp->left;
@@ -1112,6 +1138,9 @@
break;
}
switch (right) {
+ case TOMOYO_NAME_UNION:
+ names_p++;
+ break;
case TOMOYO_NUMBER_UNION:
numbers_p++;
break;
@@ -1138,6 +1167,10 @@
}
tomoyo_set_string(head, match ? "=" : "!=");
switch (right) {
+ case TOMOYO_NAME_UNION:
+ tomoyo_print_name_union_quoted
+ (head, names_p++);
+ break;
case TOMOYO_NUMBER_UNION:
tomoyo_print_number_union_nospace
(head, numbers_p++);
@@ -1666,6 +1699,22 @@
static atomic_t tomoyo_query_observers = ATOMIC_INIT(0);
/**
+ * tomoyo_truncate - Truncate a line.
+ *
+ * @str: String to truncate.
+ *
+ * Returns length of truncated @str.
+ */
+static int tomoyo_truncate(char *str)
+{
+ char *start = str;
+ while (*(unsigned char *) str > (unsigned char) ' ')
+ str++;
+ *str = '\0';
+ return strlen(start) + 1;
+}
+
+/**
* tomoyo_add_entry - Add an ACL to current thread's domain. Used by learning mode.
*
* @domain: Pointer to "struct tomoyo_domain_info".
@@ -1676,6 +1725,8 @@
static void tomoyo_add_entry(struct tomoyo_domain_info *domain, char *header)
{
char *buffer;
+ char *realpath = NULL;
+ char *symlink = NULL;
char *cp = strchr(header, '\n');
int len;
if (!cp)
@@ -1685,10 +1736,25 @@
return;
*cp++ = '\0';
len = strlen(cp) + 1;
+ /* strstr() will return NULL if ordering is wrong. */
+ if (*cp == 'f') {
+ realpath = strstr(header, " exec={ realpath=\"");
+ if (realpath) {
+ realpath += 8;
+ len += tomoyo_truncate(realpath) + 6;
+ }
+ symlink = strstr(header, " symlink.target=\"");
+ if (symlink)
+ len += tomoyo_truncate(symlink + 1) + 1;
+ }
buffer = kmalloc(len, GFP_NOFS);
if (!buffer)
return;
snprintf(buffer, len - 1, "%s", cp);
+ if (realpath)
+ tomoyo_addprintf(buffer, len, " exec.%s", realpath);
+ if (symlink)
+ tomoyo_addprintf(buffer, len, "%s", symlink);
tomoyo_normalize_line(buffer);
if (!tomoyo_write_domain2(domain->ns, &domain->acl_info_list, buffer,
false))