From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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; } -- 2.13.6