diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index f77f6b3d24b9..f7c65ca056f8 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2271,10 +2271,7 @@ static noinline int btrfs_ioctl_ino_lookup(struct file *file, { struct btrfs_ioctl_ino_lookup_args *args; struct inode *inode; - int ret; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; + int ret = 0; args = memdup_user(argp, sizeof(*args)); if (IS_ERR(args)) @@ -2282,13 +2279,28 @@ static noinline int btrfs_ioctl_ino_lookup(struct file *file, inode = file_inode(file); + /* + * Unprivileged query to obtain the containing subvolume root id. The + * path is reset so it's consistent with btrfs_search_path_in_tree. + */ if (args->treeid == 0) args->treeid = BTRFS_I(inode)->root->root_key.objectid; + if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) { + args->name[0] = 0; + goto out; + } + + if (!capable(CAP_SYS_ADMIN)) { + ret = -EPERM; + goto out; + } + ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info, args->treeid, args->objectid, args->name); +out: if (ret == 0 && copy_to_user(argp, args, sizeof(*args))) ret = -EFAULT;