From patchwork Mon Dec 10 17:13:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vivek Goyal X-Patchwork-Id: 10721915 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8578514E2 for ; Mon, 10 Dec 2018 17:18:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 69BCC2AF3D for ; Mon, 10 Dec 2018 17:18:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5D82E2AF42; Mon, 10 Dec 2018 17:18:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0309F2AF3D for ; Mon, 10 Dec 2018 17:18:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727912AbeLJRRu (ORCPT ); Mon, 10 Dec 2018 12:17:50 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50526 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728401AbeLJRNf (ORCPT ); Mon, 10 Dec 2018 12:13:35 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C0D1930001DF; Mon, 10 Dec 2018 17:13:35 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.234]) by smtp.corp.redhat.com (Postfix) with ESMTP id 787AA605C5; Mon, 10 Dec 2018 17:13:35 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id B170C224278; Mon, 10 Dec 2018 12:13:30 -0500 (EST) From: Vivek Goyal To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: vgoyal@redhat.com, miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com, sweil@redhat.com, swhiteho@redhat.com Subject: [PATCH 44/52] fuse: Clear setuid bit even in direct I/O path Date: Mon, 10 Dec 2018 12:13:10 -0500 Message-Id: <20181210171318.16998-45-vgoyal@redhat.com> In-Reply-To: <20181210171318.16998-1-vgoyal@redhat.com> References: <20181210171318.16998-1-vgoyal@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Mon, 10 Dec 2018 17:13:35 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP With cache=never, we fall back to direct IO. pjdfstest chmod test 12.t was failing because if a file has setuid bit, it should be cleared if an unpriviledged user opens it for write and writes to it. Call fuse_remove_privs() even for direct I/O path. Signed-off-by: Vivek Goyal --- fs/fuse/file.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index cb28cf26a6e7..0be5a7380b3c 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1679,13 +1679,25 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from) /* Don't allow parallel writes to the same file */ inode_lock(inode); res = generic_write_checks(iocb, from); - if (res > 0) - res = fuse_direct_io(&io, from, &iocb->ki_pos, FUSE_DIO_WRITE); + if (res < 0) + goto out_invalidate; + + res = file_remove_privs(iocb->ki_filp); + if (res) + goto out_invalidate; + + res = fuse_direct_io(&io, from, &iocb->ki_pos, FUSE_DIO_WRITE); + if (res < 0) + goto out_invalidate; + fuse_invalidate_attr(inode); - if (res > 0) - fuse_write_update_size(inode, iocb->ki_pos); + fuse_write_update_size(inode, iocb->ki_pos); inode_unlock(inode); + return res; +out_invalidate: + fuse_invalidate_attr(inode); + inode_unlock(inode); return res; }