udev-builtin-btrfs: refuse to call for irrelevant device node

If btrfs builtin command is called, then check if the specified device
node is owned by the device.
This also allows the command is called specifying any device node.

diff --git a/src/udev/udev-builtin-btrfs.c b/src/udev/udev-builtin-btrfs.c
index 200b069efa6fbc036e0bf24da7dbbebea88c1b8f..a1238f1e1b3b873c57ca24342c04536bc7222dc6 100644 (file)
--- a/src/udev/udev-builtin-btrfs.c
+++ b/src/udev/udev-builtin-btrfs.c
@@ -16,11 +16,19 @@ static int builtin_btrfs(UdevEvent *event, int argc, char *argv[]) {
         sd_device *dev = ASSERT_PTR(ASSERT_PTR(event)->dev);
         int r;
 
-        if (argc != 3 || !streq(argv[1], "ready"))
-                return log_device_error_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Invalid arguments");
+        if (!IN_SET(argc, 2, 3) || !streq(argv[1], "ready"))
+                return log_device_error_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Invalid arguments.");
 
-        if (strlen(argv[2]) >= sizeof_field(struct btrfs_ioctl_vol_args, name))
-                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Device name too long for BTRFS_IOC_DEVICES_READY call: %s", argv[2]);
+        const char *node;
+        r = sd_device_get_devname(dev, &node);
+        if (r < 0)
+                return log_device_error_errno(dev, r, "Failed to get device node: %m");
+
+        if (argc == 3 && !streq(argv[2], node))
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Device node '%s' is not owned by the device, it must be '%s'.", argv[2], node);
+
+        if (strlen(node) >= sizeof_field(struct btrfs_ioctl_vol_args, name))
+                return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Device name too long for BTRFS_IOC_DEVICES_READY call: %s", node);
 
         if (event->event_mode != EVENT_UDEV_WORKER) {
                 log_device_debug(dev, "Running in test mode, skipping execution of 'btrfs' builtin command.");
@@ -41,7 +49,7 @@ static int builtin_btrfs(UdevEvent *event, int argc, char *argv[]) {
         }
 
         struct btrfs_ioctl_vol_args args = {};
-        strncpy(args.name, argv[2], sizeof(args.name)-1);
+        strncpy(args.name, node, sizeof(args.name)-1);
         r = ioctl(fd, BTRFS_IOC_DEVICES_READY, &args);
         if (r < 0)
                 return log_device_debug_errno(dev, errno, "Failed to call BTRFS_IOC_DEVICES_READY: %m");