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, 58 insertions, 78 deletions

diff --git a/security/tomoyo/file.c b/security/tomoyo/file.c
index c13806937dc6..cef685415df1 100644
--- a/security/tomoyo/file.c
+++ b/security/tomoyo/file.c
@@ -148,6 +148,17 @@ const char *tomoyo_path_number2keyword(const u8 operation)
                 ? tomoyo_path_number_keyword[operation] : NULL;
 }
 
+static void tomoyo_add_slash(struct tomoyo_path_info *buf)
+{
+        if (buf->is_dir)
+                return;
+        /*
+         * This is OK because tomoyo_encode() reserves space for appending "/".
+         */
+        strcat((char *) buf->name, "/");
+        tomoyo_fill_path_info(buf);
+}
+
 /**
  * tomoyo_strendswith - Check whether the token ends with the given token.
  *
@@ -167,30 +178,21 @@ static bool tomoyo_strendswith(const char *name, const char *tail)
 }
 
 /**
- * tomoyo_get_path - Get realpath.
+ * tomoyo_get_realpath - Get realpath.
  *
+ * @buf:  Pointer to "struct tomoyo_path_info".
  * @path: Pointer to "struct path".
  *
- * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
+ * Returns true on success, false otherwise.
  */
-static struct tomoyo_path_info *tomoyo_get_path(struct path *path)
+static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, struct path *path)
 {
-        int error;
-        struct tomoyo_path_info_with_data *buf = kzalloc(sizeof(*buf),
-                                                         GFP_NOFS);
-
-        if (!buf)
-                return NULL;
-        /* Reserve one byte for appending "/". */
-        error = tomoyo_realpath_from_path2(path, buf->body,
-                                           sizeof(buf->body) - 2);
-        if (!error) {
-                buf->head.name = buf->body;
-                tomoyo_fill_path_info(&buf->head);
-                return &buf->head;
+        buf->name = tomoyo_realpath_from_path(path);
+        if (buf->name) {
+                tomoyo_fill_path_info(buf);
+                return true;
         }
-        kfree(buf);
-        return NULL;
+        return false;
 }
 
 static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
@@ -1259,26 +1261,20 @@ int tomoyo_path_number_perm(const u8 type, struct path *path,
 {
         struct tomoyo_request_info r;
         int error = -ENOMEM;
-        struct tomoyo_path_info *buf;
+        struct tomoyo_path_info buf;
         int idx;
 
         if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED ||
             !path->mnt || !path->dentry)
                 return 0;
         idx = tomoyo_read_lock();
-        buf = tomoyo_get_path(path);
-        if (!buf)
+        if (!tomoyo_get_realpath(&buf, path))
                 goto out;
-        if (type == TOMOYO_TYPE_MKDIR && !buf->is_dir) {
-                /*
-                 * tomoyo_get_path() reserves space for appending "/."
-                 */
-                strcat((char *) buf->name, "/");
-                tomoyo_fill_path_info(buf);
-        }
-        error = tomoyo_path_number_perm2(&r, type, buf, number);
+        if (type == TOMOYO_TYPE_MKDIR)
+                tomoyo_add_slash(&buf);
+        error = tomoyo_path_number_perm2(&r, type, &buf, number);
  out:
-        kfree(buf);
+        kfree(buf.name);
         tomoyo_read_unlock(idx);
         if (r.mode != TOMOYO_CONFIG_ENFORCING)
                 error = 0;
@@ -1319,7 +1315,7 @@ int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
 {
         const u8 acc_mode = ACC_MODE(flag);
         int error = -ENOMEM;
-        struct tomoyo_path_info *buf;
+        struct tomoyo_path_info buf;
         struct tomoyo_request_info r;
         int idx;
 
@@ -1335,8 +1331,7 @@ int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
                  */
                 return 0;
         idx = tomoyo_read_lock();
-        buf = tomoyo_get_path(path);
-        if (!buf)
+        if (!tomoyo_get_realpath(&buf, path))
                 goto out;
         error = 0;
         /*
@@ -1346,15 +1341,15 @@ int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
          */
         if ((acc_mode & MAY_WRITE) &&
             ((flag & O_TRUNC) || !(flag & O_APPEND)) &&
-            (tomoyo_is_no_rewrite_file(buf))) {
-                error = tomoyo_path_permission(&r, TOMOYO_TYPE_REWRITE, buf);
+            (tomoyo_is_no_rewrite_file(&buf))) {
+                error = tomoyo_path_permission(&r, TOMOYO_TYPE_REWRITE, &buf);
         }
         if (!error)
-                error = tomoyo_file_perm(&r, buf, acc_mode);
+                error = tomoyo_file_perm(&r, &buf, acc_mode);
         if (!error && (flag & O_TRUNC))
-                error = tomoyo_path_permission(&r, TOMOYO_TYPE_TRUNCATE, buf);
+                error = tomoyo_path_permission(&r, TOMOYO_TYPE_TRUNCATE, &buf);
  out:
-        kfree(buf);
+        kfree(buf.name);
         tomoyo_read_unlock(idx);
         if (r.mode != TOMOYO_CONFIG_ENFORCING)
                 error = 0;
@@ -1372,7 +1367,7 @@ int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
 int tomoyo_path_perm(const u8 operation, struct path *path)
 {
         int error = -ENOMEM;
-        struct tomoyo_path_info *buf;
+        struct tomoyo_path_info buf;
         struct tomoyo_request_info r;
         int idx;
 
@@ -1380,29 +1375,23 @@ int tomoyo_path_perm(const u8 operation, struct path *path)
             !path->mnt)
                 return 0;
         idx = tomoyo_read_lock();
-        buf = tomoyo_get_path(path);
-        if (!buf)
+        if (!tomoyo_get_realpath(&buf, path))
                 goto out;
         switch (operation) {
         case TOMOYO_TYPE_REWRITE:
-                if (!tomoyo_is_no_rewrite_file(buf)) {
+                if (!tomoyo_is_no_rewrite_file(&buf)) {
                         error = 0;
                         goto out;
                 }
                 break;
         case TOMOYO_TYPE_RMDIR:
         case TOMOYO_TYPE_CHROOT:
-                if (!buf->is_dir) {
-                        /*
-                         * tomoyo_get_path() reserves space for appending "/."
-                         */
-                        strcat((char *) buf->name, "/");
-                        tomoyo_fill_path_info(buf);
-                }
+                tomoyo_add_slash(&buf);
+                break;
         }
-        error = tomoyo_path_permission(&r, operation, buf);
+        error = tomoyo_path_permission(&r, operation, &buf);
  out:
-        kfree(buf);
+        kfree(buf.name);
         tomoyo_read_unlock(idx);
         if (r.mode != TOMOYO_CONFIG_ENFORCING)
                 error = 0;
@@ -1465,7 +1454,7 @@ int tomoyo_path_number3_perm(const u8 operation, struct path *path,
 {
         struct tomoyo_request_info r;
         int error = -ENOMEM;
-        struct tomoyo_path_info *buf;
+        struct tomoyo_path_info buf;
         int idx;
 
         if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED ||
@@ -1473,11 +1462,10 @@ int tomoyo_path_number3_perm(const u8 operation, struct path *path,
                 return 0;
         idx = tomoyo_read_lock();
         error = -ENOMEM;
-        buf = tomoyo_get_path(path);
-        if (buf) {
-                error = tomoyo_path_number3_perm2(&r, operation, buf, mode,
+        if (tomoyo_get_realpath(&buf, path)) {
+                error = tomoyo_path_number3_perm2(&r, operation, &buf, mode,
                                                   new_decode_dev(dev));
-                kfree(buf);
+                kfree(buf.name);
         }
         tomoyo_read_unlock(idx);
         if (r.mode != TOMOYO_CONFIG_ENFORCING)
@@ -1499,48 +1487,40 @@ int tomoyo_path2_perm(const u8 operation, struct path *path1,
 {
         int error = -ENOMEM;
         const char *msg;
-        struct tomoyo_path_info *buf1;
-        struct tomoyo_path_info *buf2;
+        struct tomoyo_path_info buf1;
+        struct tomoyo_path_info buf2;
         struct tomoyo_request_info r;
         int idx;
 
         if (tomoyo_init_request_info(&r, NULL) == TOMOYO_CONFIG_DISABLED ||
             !path1->mnt || !path2->mnt)
                 return 0;
+        buf1.name = NULL;
+        buf2.name = NULL;
         idx = tomoyo_read_lock();
-        buf1 = tomoyo_get_path(path1);
-        buf2 = tomoyo_get_path(path2);
-        if (!buf1 || !buf2)
+        if (!tomoyo_get_realpath(&buf1, path1) ||
+            !tomoyo_get_realpath(&buf2, path2))
                 goto out;
         {
                 struct dentry *dentry = path1->dentry;
                 if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
-                        /*
-                         * tomoyo_get_path() reserves space for appending "/."
-                         */
-                        if (!buf1->is_dir) {
-                                strcat((char *) buf1->name, "/");
-                                tomoyo_fill_path_info(buf1);
-                        }
-                        if (!buf2->is_dir) {
-                                strcat((char *) buf2->name, "/");
-                                tomoyo_fill_path_info(buf2);
-                        }
+                        tomoyo_add_slash(&buf1);
+                        tomoyo_add_slash(&buf2);
                 }
         }
         do {
-                error = tomoyo_path2_acl(&r, operation, buf1, buf2);
+                error = tomoyo_path2_acl(&r, operation, &buf1, &buf2);
                 if (!error)
                         break;
                 msg = tomoyo_path22keyword(operation);
-                tomoyo_warn_log(&r, "%s %s %s", msg, buf1->name, buf2->name);
+                tomoyo_warn_log(&r, "%s %s %s", msg, buf1.name, buf2.name);
                 error = tomoyo_supervisor(&r, "allow_%s %s %s\n", msg,
-                                          tomoyo_file_pattern(buf1),
-                                          tomoyo_file_pattern(buf2));
+                                          tomoyo_file_pattern(&buf1),
+                                          tomoyo_file_pattern(&buf2));
         } while (error == TOMOYO_RETRY_REQUEST);
  out:
-        kfree(buf1);
-        kfree(buf2);
+        kfree(buf1.name);
+        kfree(buf2.name);
         tomoyo_read_unlock(idx);
         if (r.mode != TOMOYO_CONFIG_ENFORCING)
                 error = 0;