linux-kernel - Re: [PATCH v7 0/7] Add O_DENY* support for VFS and CIFS/NFS

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <E1W5C8U-000ozD-Ku@intern.SerNet.DE>
Date:	Mon, 20 Jan 2014 11:31:13 +0100
From:	Volker Lendecke <Volker.Lendecke@...Net.DE>
To:	Pavel Shilovsky <piastry@...rsoft.ru>
Cc:	Kernel Mailing List <linux-kernel@...r.kernel.org>,
	linux-cifs <linux-cifs@...r.kernel.org>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	Linux NFS Mailing list <linux-nfs@...r.kernel.org>,
	wine-devel@...ehq.org
Subject: Re: [PATCH v7 0/7] Add O_DENY* support for VFS and CIFS/NFS

On Mon, Jan 20, 2014 at 02:20:43PM +0400, Pavel Shilovsky wrote:
> > One question: If Samba wants to open a file for delete
> > access, there's no corresponding flag in the open
> > permissions. There can be the case where Samba wants to open
> > *just* for future unlink, no read or write access required.
> > Is there a way to achieve this atomically correct?
> 
> You can try to use O_PATH flag. It doesn't give you a delete access
> but should be ok because further deleting will be done without file
> descriptor -- through unlink syscall.

Ok, I did not know about O_PATH. Thanks for that!

So I do an open with O_PATH. How do I then make sure that
nobody else has a O_DENYDELETE set without doing the unlink
itself?

Thanks,

Volker

-- 
SerNet GmbH, Bahnhofsallee 1b, 37081 Göttingen
phone: +49-551-370000-0, fax: +49-551-370000-9
AG Göttingen, HRB 2816, GF: Dr. Johannes Loxen
http://www.sernet.de, mailto:kontakt@...net.de
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/