TOMOYO: Support longer pathname.

Allow pathnames longer than 4000 bytes.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 33 insertions, 39 deletions

diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index 08428bc082df..7b8693e29a13 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -676,47 +676,43 @@ struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
 int tomoyo_find_next_domain(struct linux_binprm *bprm)
 {
         struct tomoyo_request_info r;
-        /*
-         * This function assumes that the size of buffer returned by
-         * tomoyo_realpath() = TOMOYO_MAX_PATHNAME_LEN.
-         */
-        struct tomoyo_page_buffer *tmp = kzalloc(sizeof(*tmp), GFP_NOFS);
+        char *tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
         struct tomoyo_domain_info *old_domain = tomoyo_domain();
         struct tomoyo_domain_info *domain = NULL;
         const char *old_domain_name = old_domain->domainname->name;
         const char *original_name = bprm->filename;
-        char *new_domain_name = NULL;
-        char *real_program_name = NULL;
-        char *symlink_program_name = NULL;
         const u8 mode = tomoyo_check_flags(old_domain, TOMOYO_MAC_FOR_FILE);
         const bool is_enforce = (mode == TOMOYO_CONFIG_ENFORCING);
         int retval = -ENOMEM;
-        struct tomoyo_path_info rn; /* real name */
-        struct tomoyo_path_info sn; /* symlink name */
+        bool need_kfree = false;
+        struct tomoyo_path_info rn = { }; /* real name */
+        struct tomoyo_path_info sn = { }; /* symlink name */
         struct tomoyo_path_info ln; /* last name */
 
+        ln.name = tomoyo_get_last_name(old_domain);
+        tomoyo_fill_path_info(&ln);
         tomoyo_init_request_info(&r, NULL);
         if (!tmp)
                 goto out;
 
  retry:
+        if (need_kfree) {
+                kfree(rn.name);
+                need_kfree = false;
+        }
         /* Get tomoyo_realpath of program. */
         retval = -ENOENT;
-        /* I hope tomoyo_realpath() won't fail with -ENOMEM. */
-        real_program_name = tomoyo_realpath(original_name);
-        if (!real_program_name)
+        rn.name = tomoyo_realpath(original_name);
+        if (!rn.name)
                 goto out;
+        tomoyo_fill_path_info(&rn);
+        need_kfree = true;
+
         /* Get tomoyo_realpath of symbolic link. */
-        symlink_program_name = tomoyo_realpath_nofollow(original_name);
-        if (!symlink_program_name)
+        sn.name = tomoyo_realpath_nofollow(original_name);
+        if (!sn.name)
                 goto out;
-
-        rn.name = real_program_name;
-        tomoyo_fill_path_info(&rn);
-        sn.name = symlink_program_name;
         tomoyo_fill_path_info(&sn);
-        ln.name = tomoyo_get_last_name(old_domain);
-        tomoyo_fill_path_info(&ln);
 
         /* Check 'alias' directive. */
         if (tomoyo_pathcmp(&rn, &sn)) {
@@ -727,10 +723,10 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
                             tomoyo_pathcmp(&rn, ptr->original_name) ||
                             tomoyo_pathcmp(&sn, ptr->aliased_name))
                                 continue;
-                        memset(real_program_name, 0, TOMOYO_MAX_PATHNAME_LEN);
-                        strncpy(real_program_name, ptr->aliased_name->name,
-                                TOMOYO_MAX_PATHNAME_LEN - 1);
-                        tomoyo_fill_path_info(&rn);
+                        kfree(rn.name);
+                        need_kfree = false;
+                        /* This is OK because it is read only. */
+                        rn = *ptr->aliased_name;
                         break;
                 }
         }
@@ -742,11 +738,10 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
         if (retval < 0)
                 goto out;
 
-        new_domain_name = tmp->buffer;
         if (tomoyo_is_domain_initializer(old_domain->domainname, &rn, &ln)) {
                 /* Transit to the child of tomoyo_kernel_domain domain. */
-                snprintf(new_domain_name, TOMOYO_MAX_PATHNAME_LEN + 1,
-                         TOMOYO_ROOT_NAME " " "%s", real_program_name);
+                snprintf(tmp, TOMOYO_EXEC_TMPSIZE - 1,
+                         TOMOYO_ROOT_NAME " " "%s", rn.name);
         } else if (old_domain == &tomoyo_kernel_domain &&
                    !tomoyo_policy_loaded) {
                 /*
@@ -760,29 +755,27 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
                 domain = old_domain;
         } else {
                 /* Normal domain transition. */
-                snprintf(new_domain_name, TOMOYO_MAX_PATHNAME_LEN + 1,
-                         "%s %s", old_domain_name, real_program_name);
+                snprintf(tmp, TOMOYO_EXEC_TMPSIZE - 1,
+                         "%s %s", old_domain_name, rn.name);
         }
-        if (domain || strlen(new_domain_name) >= TOMOYO_MAX_PATHNAME_LEN)
+        if (domain || strlen(tmp) >= TOMOYO_EXEC_TMPSIZE - 10)
                 goto done;
-        domain = tomoyo_find_domain(new_domain_name);
+        domain = tomoyo_find_domain(tmp);
         if (domain)
                 goto done;
         if (is_enforce) {
                 int error = tomoyo_supervisor(&r, "# wants to create domain\n"
-                                              "%s\n", new_domain_name);
+                                              "%s\n", tmp);
                 if (error == TOMOYO_RETRY_REQUEST)
                         goto retry;
                 if (error < 0)
                         goto done;
         }
-        domain = tomoyo_find_or_assign_new_domain(new_domain_name,
-                                                  old_domain->profile);
+        domain = tomoyo_find_or_assign_new_domain(tmp, old_domain->profile);
  done:
         if (domain)
                 goto out;
-        printk(KERN_WARNING "TOMOYO-ERROR: Domain '%s' not defined.\n",
-               new_domain_name);
+        printk(KERN_WARNING "TOMOYO-ERROR: Domain '%s' not defined.\n", tmp);
         if (is_enforce)
                 retval = -EPERM;
         else
@@ -793,8 +786,9 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
         /* Update reference count on "struct tomoyo_domain_info". */
         atomic_inc(&domain->users);
         bprm->cred->security = domain;
-        kfree(real_program_name);
-        kfree(symlink_program_name);
+        if (need_kfree)
+                kfree(rn.name);
+        kfree(sn.name);
         kfree(tmp);
         return retval;
 }