From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B0CBC433B4 for ; Sat, 17 Apr 2021 08:40:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3012F6113D for ; Sat, 17 Apr 2021 08:40:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229972AbhDQIkn (ORCPT ); Sat, 17 Apr 2021 04:40:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:34010 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229631AbhDQIkn (ORCPT ); Sat, 17 Apr 2021 04:40:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7D9AF61007; Sat, 17 Apr 2021 08:40:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1618648817; bh=MZpm1e0oUW6USsAyZ0mf1APVCyK3fJEOWX9uCb6poD8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DtsFPx4YMEvtVrxmBt6y6zbhAlY48jCMDkjT7Ftnr3aEmDbwLXOxvr2jQK2fw5g/E MonTJcWYX7TyG0NGr+K6BMfp59JrYVzxZayX7w/Lo1CX4FOjJFRDXrcAFaQvKwdo5U T9/XJRTi2MXH74KnKnk+V6syy2S27A8UIDwYNztQ= Date: Sat, 17 Apr 2021 10:40:14 +0200 From: Greg Kroah-Hartman To: Salvatore Bonaccorso Cc: stable , Sasha Levin , Miklos Szeredi , James Morris , Steve Beattie Subject: Re: Please apply commit 7c03e2cda4a5 ("vfs: move cap_convert_nscap() call into vfs_setxattr()") to stable series from 5.10.y back to 4.19.y Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Apr 16, 2021 at 09:56:08PM +0200, Salvatore Bonaccorso wrote: > Hi Greg, hi Sasha > > Please consider to apply commit 7c03e2cda4a5 ("vfs: move > cap_convert_nscap() call into vfs_setxattr()") to stable series at > least back to 4.19.y. It applies to there (but have not tested older > series) and could test a build on top of 5.10.y with the commit. > > The commit was applied in 5.11-rc1 and from the commit message: > > vfs: move cap_convert_nscap() call into vfs_setxattr() > > cap_convert_nscap() does permission checking as well as conversion of the > xattr value conditionally based on fs's user-ns. > > This is needed by overlayfs and probably other layered fs (ecryptfs) and is > what vfs_foo() is supposed to do anyway. Does this actually solve an in-kernel problem, or is only an issue for out-of-tree filesystems? > Additionally, in fact additionally for distribtuions kernels which do > allow unprivileged overlayfs mounts this as as well broader > consequences, as explained in > https://www.openwall.com/lists/oss-security/2021/04/16/1 . That's an out-of-tree issue from what I can tell, what in-kernel issue does the above commit resolve? Or am I reading that report incorrectly? thanks, greg k-h