From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:38078 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727405AbeI3CQc (ORCPT ); Sat, 29 Sep 2018 22:16:32 -0400 Date: Sat, 29 Sep 2018 12:44:29 -0700 From: Matthew Wilcox Subject: Re: [PATCH 0/3] namei: implement various scoping AT_* flags Message-ID: <20180929194429.GA1702@bombadil.infradead.org> References: <20180929103453.12025-1-cyphar@cyphar.com> <1EE20CA2-4C8B-4A80-B613-0277D92B376D@amacapital.net> <20180929154551.jsi6dt3xjxdxoqeh@ryuk> <9D01A225-05BE-4B4A-873A-94168D17F687@amacapital.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9D01A225-05BE-4B4A-873A-94168D17F687@amacapital.net> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Andy Lutomirski Cc: Aleksa Sarai , Jeff Layton , "J. Bruce Fields" , Al Viro , Arnd Bergmann , Shuah Khan , David Howells , Andy Lutomirski , Christian Brauner , Eric Biederman , Tycho Andersen , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, dev@opencontainers.org, containers@lists.linux-foundation.org Message-ID: <20180929194429.h5Xxq29AjqpYw1IaCjhkaV8l8Go_zn433_TpWymTO4I@z> On Sat, Sep 29, 2018 at 09:34:24AM -0700, Andy Lutomirski wrote: > Also, as a perhaps-silly suggestion: if you end up adding a new > syscall, I can see a use for a mode that does the path walk but, rather > than failing on a disallowed link, stops early and indicates where it > stopped. Then web servers, samba, etc can more efficiently implement > custom behavior when links are encountered. And it may also be useful > to have a variant of AT_THIS_ROOT where trying to escape is an error > instead of having it just get stuck at the root. AT_USER_LINKS indicating that userspace wants to resolve symlinks themselves?