Merge pull request #1517 from sohankunkerkar/fix-trailing-slash

src/libcrun: fix handling of device paths with trailing slashes

src/libcrun/linux.c

@@ -1611,7 +1611,14 @@ libcrun_create_dev (libcrun_container_t *container, int devfd, int srcfd,
   int rootfsfd = get_private_data (container)->rootfsfd;
   const char *rootfs = get_private_data (container)->rootfs;
   size_t rootfs_len = get_private_data (container)->rootfs_len;
-  const char *rel_dev = relative_path_under_dev (device->path);
+  if (is_empty_string (fullname))
+    return crun_make_error (err, EINVAL, "device path is empty");
+  // Normalize the path by removing trailing slashes.
+  cleanup_free char *normalized_path = xstrdup (fullname);
+  consume_trailing_slashes (normalized_path);
+  if (normalized_path[0] == '\0')
+    strcpy (normalized_path, "/");
+  const char *rel_dev = relative_path_under_dev (normalized_path);
 
   if (binds)
     {
@@ -1631,7 +1638,7 @@ libcrun_create_dev (libcrun_container_t *container, int devfd, int srcfd,
         }
       else
         {
-          const char *rel_path = consume_slashes (device->path);
+          const char *rel_path = consume_slashes (normalized_path);
 
           fd = crun_safe_create_and_open_ref_at (false, rootfsfd, rootfs, rootfs_len, rel_path, 0755, err);
           if (UNLIKELY (fd < 0))
@@ -1645,7 +1652,7 @@ libcrun_create_dev (libcrun_container_t *container, int devfd, int srcfd,
             return 0;
         }
 
-      ret = do_mount (container, fullname, fd, device->path, NULL, MS_BIND | MS_PRIVATE | MS_NOEXEC | MS_NOSUID, NULL, LABEL_MOUNT, err);
+      ret = do_mount (container, fullname, fd, normalized_path, NULL, MS_BIND | MS_PRIVATE | MS_NOEXEC | MS_NOSUID, NULL, LABEL_MOUNT, err);
       if (UNLIKELY (ret < 0))
         return ret;
     }
@@ -1684,17 +1691,17 @@ libcrun_create_dev (libcrun_container_t *container, int devfd, int srcfd,
         }
       else
         {
-          char *dirname;
-          cleanup_free char *buffer = NULL;
           cleanup_close int dirfd = -1;
-          char *basename, *tmp;
+          cleanup_free char *dirname = NULL;
+          char *basename, *found;
 
-          buffer = xstrdup (device->path);
-          dirname = buffer;
+          dirname = xstrdup (normalized_path);
 
-          tmp = strrchr (buffer, '/');
-          *tmp = '\0';
-          basename = tmp + 1;
+          found = strrchr (dirname, '/');
+          if (found)
+            *found = '\0';
+
+          basename = found ? found + 1 : dirname;
 
           if (dirname[0] == '\0')
             dirfd = dup (rootfsfd);

src/libcrun/utils.c

@@ -2507,3 +2507,17 @@ get_overflow_gid (void)
     }
   return gid;
 }
+
+void
+consume_trailing_slashes (char *path)
+{
+  if (! path || path[0] == '\0')
+    return;
+
+  char *last = path + strlen (path);
+
+  while (last > path && *(last - 1) == '/')
+    last--;
+
+  *last = '\0';
+}

src/libcrun/utils.h

@@ -225,6 +225,8 @@ xstrdup (const char *str)
   return ret;
 }
 
+void consume_trailing_slashes (char *path);
+
 static inline const char *
 consume_slashes (const char *t)
 {

tests/test_devices.py

@@ -214,6 +214,19 @@ def test_mknod_device():
         return -1
     return 0
 
+def test_trailing_slash_mknod_device():
+    if is_rootless():
+        return 77
+
+    conf = base_config()
+    add_all_namespaces(conf)
+    conf['process']['args'] = ['/init', 'true']
+    conf['linux']['devices'] = [{"path": "/mnt/", "type": "b", "major": 10, "minor": 229}]
+    try:
+        run_and_get_output(conf)
+    except Exception as e:
+        return -1
+    return 0
 
 all_tests = {
     "owner-device" : test_owner_device,
@@ -223,6 +236,7 @@ def test_mknod_device():
     "mknod-device" : test_mknod_device,
     "mode-device"  : test_mode_device,
     "create-or-bind-mount-device" : test_create_or_bind_mount_device,
+    "handle-device-trailing-slash" : test_trailing_slash_mknod_device,
 }
 
 if __name__ == "__main__":