Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Nikolaus Rath <Nikolaus@rath.org>
To:     Miklos Szeredi <miklos@szeredi.hu>
Cc:     Vivek Goyal <vgoyal@redhat.com>, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        linux-nvdimm@lists.01.org, stefanha@redhat.com,
        dgilbert@redhat.com, swhiteho@redhat.com
Subject: Re: [PATCH v2 02/30] fuse: Clear setuid bit even in cache=never path
References: <20190515192715.18000-1-vgoyal@redhat.com>
        <20190515192715.18000-3-vgoyal@redhat.com>
        <20190520144137.GA24093@localhost.localdomain>
        <20190520144437.GB24093@localhost.localdomain>
Mail-Copies-To: never
Mail-Followup-To: Miklos Szeredi <miklos@szeredi.hu>, Vivek Goyal
        <vgoyal@redhat.com>, linux-fsdevel@vger.kernel.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        linux-nvdimm@lists.01.org, stefanha@redhat.com, dgilbert@redhat.com,
        swhiteho@redhat.com
Date:   Mon, 20 May 2019 21:25:49 +0100
In-Reply-To: <20190520144437.GB24093@localhost.localdomain> (Miklos Szeredi's
        message of "Mon, 20 May 2019 16:44:37 +0200")
Message-ID: <87k1ekub3m.fsf@vostro.rath.org>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On May 20 2019, Miklos Szeredi <miklos@szeredi.hu> wrote:
> On Mon, May 20, 2019 at 04:41:37PM +0200, Miklos Szeredi wrote:
>> On Wed, May 15, 2019 at 03:26:47PM -0400, Vivek Goyal wrote:
>> > If fuse daemon is started with cache=3Dnever, fuse falls back to direc=
t IO.
>> > In that write path we don't call file_remove_privs() and that means se=
tuid
>> > bit is not cleared if unpriviliged user writes to a file with setuid b=
it set.
>> >=20
>> > pjdfstest chmod test 12.t tests this and fails.
>>=20
>> I think better sulution is to tell the server if the suid bit needs to be
>> removed, so it can do so in a race free way.
>>=20
>> Here's the kernel patch, and I'll reply with the libfuse patch.
>
> Here are the patches for libfuse and passthrough_ll.

Could you also submit them as pull requests at https://github.com/libfuse/l=
ibfuse/pulls?

Best,
-Nikolaus

--=20
GPG Fingerprint: ED31 791B 2C5C 1613 AF38 8B8A D113 FCAC 3C4E 599F

             =C2=BBTime flies like an arrow, fruit flies like a Banana.=C2=
=AB