From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1a6Q5D-0005E4-8s for user-mode-linux-devel@lists.sourceforge.net; Tue, 08 Dec 2015 21:46:03 +0000 Received: from a.ns.miles-group.at ([95.130.255.143] helo=radon.swed.at) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1a6Q5C-0007MP-BJ for user-mode-linux-devel@lists.sourceforge.net; Tue, 08 Dec 2015 21:46:03 +0000 References: <1448805802-12156-1-git-send-email-mic@digikod.net> <1448805802-12156-2-git-send-email-mic@digikod.net> <56641CEA.5080202@digikod.net> <566449A3.6030504@digikod.net> From: Richard Weinberger Message-ID: <56674F91.8050108@nod.at> Date: Tue, 8 Dec 2015 22:45:53 +0100 MIME-Version: 1.0 In-Reply-To: List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net Subject: Re: [uml-devel] [PATCH v2 1/2] um: Set secure access mode for temporary file To: Tristan Schmelcher , =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= Cc: user-mode-linux-user@lists.sourceforge.net, Greg Kroah-Hartman , Jeff Dike , linux-kernel@vger.kernel.org, user-mode-linux-devel QW0gMDguMTIuMjAxNSB1bSAyMTozNyBzY2hyaWViIFRyaXN0YW4gU2NobWVsY2hlcjoKPiBPbiA2 IERlY2VtYmVyIDIwMTUgYXQgMDk6NDMsIE1pY2thw6tsIFNhbGHDvG4gPG1pY0BkaWdpa29kLm5l dD4gd3JvdGU6Cj4+IFdlbGwsIEknbSBjb25jZXJuZWQgdG8gdXNlIHVtYXNrIGJlY2F1c2UgaXQg aXMgbm90IHRocmVhZC1zYWZlIGFuZCBkcml2ZXJzIG1heSB1c2UgY3JlYXRlX21lbV9maWxlKCkg aW4gYSBtdWx0aS10aGVhZGVkIGNvbnRleHQuCj4gCj4gWW91IGFyZSByaWdodC4gV2Ugc2hvdWxk IHBlcmhhcHMgc2V0IHRoZSB1bWFzayB0byAwNzAwIHBlcm1hbmVudGx5Cj4gZHVyaW5nIHByb2Nl c3Mgc3RhcnQuIEJ1dCBJIGFtIG5vdCBzdXJlIGlmIHRoaXMgd2lsbCBpbnRlcmZlcmUgd2l0aAo+ IG90aGVyIFVNTCBjb2RlLgoKSXQgKnNob3VsZCogbm90IGh1cnQuIExldCdzIHNlZSB3aGF0IGV4 cGxvZGVzLiA6KQoKPj4gSSBwcmVmZXIgdG8gc3RpY2sgdG8gZmNobW9kIGFuZCBoYW5kbGUgdGhl IHJhY2UtY29uZGl0aW9uIHdpdGggT19UTVBGSUxFIHVuc2VsbCBzb21lb25lIGlzIHN1cmUgdGhh dCB0aGlzIHdpbGwgbm90IGNyZWF0ZSBidWdzIDopCj4gCj4gVGhlIGZjaG1vZCBjYWxsIGlzIGJh c2ljYWxseSB1c2VsZXNzIGFuZCBzaG91bGQgcHJvYmFibHkgYmUgcmVtb3ZlZC4KCkkgYWdyZWUu CgpUaGFua3MsCi8vcmljaGFyZAoKLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tCl9fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClVzZXItbW9kZS1saW51eC1kZXZlbCBt YWlsaW5nIGxpc3QKVXNlci1tb2RlLWxpbnV4LWRldmVsQGxpc3RzLnNvdXJjZWZvcmdlLm5ldApo dHRwczovL2xpc3RzLnNvdXJjZWZvcmdlLm5ldC9saXN0cy9saXN0aW5mby91c2VyLW1vZGUtbGlu dXgtZGV2ZWwK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750983AbbLHVqK (ORCPT ); Tue, 8 Dec 2015 16:46:10 -0500 Received: from a.ns.miles-group.at ([95.130.255.143]:11949 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750737AbbLHVp4 (ORCPT ); Tue, 8 Dec 2015 16:45:56 -0500 Subject: Re: [PATCH v2 1/2] um: Set secure access mode for temporary file To: Tristan Schmelcher , =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= References: <1448805802-12156-1-git-send-email-mic@digikod.net> <1448805802-12156-2-git-send-email-mic@digikod.net> <56641CEA.5080202@digikod.net> <566449A3.6030504@digikod.net> Cc: linux-kernel@vger.kernel.org, Jeff Dike , Greg Kroah-Hartman , user-mode-linux-devel , user-mode-linux-user@lists.sourceforge.net From: Richard Weinberger Message-ID: <56674F91.8050108@nod.at> Date: Tue, 8 Dec 2015 22:45:53 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 08.12.2015 um 21:37 schrieb Tristan Schmelcher: > On 6 December 2015 at 09:43, Mickaël Salaün wrote: >> Well, I'm concerned to use umask because it is not thread-safe and drivers may use create_mem_file() in a multi-theaded context. > > You are right. We should perhaps set the umask to 0700 permanently > during process start. But I am not sure if this will interfere with > other UML code. It *should* not hurt. Let's see what explodes. :) >> I prefer to stick to fchmod and handle the race-condition with O_TMPFILE unsell someone is sure that this will not create bugs :) > > The fchmod call is basically useless and should probably be removed. I agree. Thanks, //richard