From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp2130.oracle.com ([141.146.126.79]:51160 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728555AbfAGRwm (ORCPT ); Mon, 7 Jan 2019 12:52:42 -0500 Date: Mon, 7 Jan 2019 09:52:29 -0800 From: "Darrick J. Wong" Subject: Re: [PATCH] xfs: correct statx's result_mask value Message-ID: <20190107175229.GJ12689@magnolia> References: <1546854790-5233-1-git-send-email-suyj.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1546854790-5233-1-git-send-email-suyj.fnst@cn.fujitsu.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Su Yanjun Cc: linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, suyanjun218@gmail.com On Mon, Jan 07, 2019 at 04:53:10AM -0500, Su Yanjun wrote: > For statx syscall, xfs return the wrong result_mask. > > Signed-off-by: Su Yanjun > --- > fs/xfs/xfs_iops.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c > index f48ffd7..3811457 100644 > --- a/fs/xfs/xfs_iops.c > +++ b/fs/xfs/xfs_iops.c > @@ -521,6 +521,9 @@ xfs_vn_getattr( > stat->btime.tv_nsec = ip->i_d.di_crtime.t_nsec; > } > } > + > + /* Only return mask that we care */ > + stat->result_mask &= request_mask; Why not just: stat->result_mask = STATX_BASIC_STATS; at the top of the function? I don't see the need to mask off result_mask at all, since we could some day elect to return more than what's in request_mask... ...waitaminute, are you seeing garbage in the result_mask that's returned to userspace? I also noticed the vfs stat functions declare "struct kstat stat;" without explicitly zeroing the structure fields, which means (I think) that we can leak stack information if the kernel isn't built with the stackleak plugin? --D > > if (ip->i_d.di_flags & XFS_DIFLAG_IMMUTABLE) > stat->attributes |= STATX_ATTR_IMMUTABLE; > -- > 2.7.4 > > >