Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755109Ab3JLBkG (ORCPT ); Fri, 11 Oct 2013 21:40:06 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:36486 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752599Ab3JLBkE (ORCPT ); Fri, 11 Oct 2013 21:40:04 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Miklos Szeredi Cc: Andy Lutomirski , "Serge E. Hallyn" , Al Viro , Linux-Fsdevel , Kernel Mailing List , Rob Landley , Linus Torvalds References: <8761v7h2pt.fsf@tw-ebiederman.twitter.com> <87li281wx6.fsf_-_@xmission.com> <87a9ioo37a.fsf_-_@xmission.com> <20131007043919.GB10284@mail.hallyn.com> <87vc191sf2.fsf@xmission.com> <87d2ngyb02.fsf@xmission.com> <20131008160601.GJ14242@tucsk.piliscsaba.szeredi.hu> <20131008161135.GK14242@tucsk.piliscsaba.szeredi.hu> <87li23trll.fsf@tw-ebiederman.twitter.com> <87vc15mjuw.fsf@xmission.com> <87iox38fkv.fsf@xmission.com> Date: Fri, 11 Oct 2013 18:39:53 -0700 In-Reply-To: <87iox38fkv.fsf@xmission.com> (Eric W. Biederman's message of "Fri, 11 Oct 2013 18:04:32 -0700") Message-ID: <87d2nb8dxy.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX18WtyBMlTRTojrRFnqpwc5905xp0CYyhcQ= X-SA-Exim-Connect-IP: 98.207.154.105 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * 1.5 TR_Symld_Words too many words that have symbols inside * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0002] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] X-Spam-DCC: XMission; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Miklos Szeredi X-Spam-Relay-Country: Subject: Re: [RFC][PATCH 4/3] vfs: Allow rmdir to remove mounts in all but the current mount namespace X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 14 Nov 2012 14:26:46 -0700) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1046 Lines: 32 ebiederm@xmission.com (Eric W. Biederman) writes: > Miklos Szeredi writes: > >> On Thu, Oct 10, 2013 at 1:43 PM, Eric W. Biederman >>> Miklos if you as the fuse maintainer aren't worried about network >>> filesystems, and multiple namespaces I won't worry either. Especially >>> since modern versions of fuse aren't affected. >> >> I think the above conditions (local mount blocks unlink/rename) are >> enough to prevent most of the problems, of which there aren't many in >> any case. > > Dumb question. > > What prevents someone setting up a race between the fusermount > permission checks and replacing the destination with a symlink, perhaps > to /etc/shadow? > > Do we need a MS_NOFOLLOW? Doh! mount(".",...) works just fine.. My apologies for the silly question. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/