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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7560C43217 for ; Wed, 19 Oct 2022 11:59:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231923AbiJSL7W (ORCPT ); Wed, 19 Oct 2022 07:59:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232071AbiJSL6N (ORCPT ); Wed, 19 Oct 2022 07:58:13 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C6B4180266; Wed, 19 Oct 2022 04:36:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 481A06066C; Wed, 19 Oct 2022 11:35:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F1B9C433C1; Wed, 19 Oct 2022 11:35:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666179323; bh=n7vNTP5zyuyxqJmFthkSvw7yT6JUrhOimlpkmNcxnlM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=W1xyFPgYyAnp+F3vS7hBYIoNbSJ6DN+3CKQl4PGuUKQ6Rzjj+mG2WfG/EF3fs02I8 2NZ9R2Jg8bKfIwrqVJ/X8BXehopAKMTV2teSNR2fwaLWcRSFS9lnLPTipqw9glOjRO jdlwO1k0ogHiVCDFywatCWyE5F3net8AE+d+hU5TQgAVxYjCWUYlOJB6y/0o4cf5/h 6a6knnlr1fgcuZcd3Zd6LFGL0YHosdc74s1PdoJy9pj2GKrGAUMRFR85A1X0RSgmjM 4rnjwIDDjU/jUIJ2gZFk3sJzoYdttksPQMdVvS6ZeMOq0vHhmI/cMs5pS0dGuQcDyZ g1gkhT48IQEhQ== Date: Wed, 19 Oct 2022 13:35:18 +0200 From: Christian Brauner To: Kees Cook Cc: Eric Biederman , linux-fsdevel@vger.kernel.org, Jann Horn , Andy Lutomirski , David Laight , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH] exec: Add comments on check_unsafe_exec() fs counting Message-ID: <20221019113518.tmbuflcinmcy5uk2@wittgenstein> References: <20221018071537.never.662-kees@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20221018071537.never.662-kees@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 18, 2022 at 12:17:24AM -0700, Kees Cook wrote: > Add some comments about what the fs counting is doing in > check_unsafe_exec() and how it relates to the call graph. > Specifically, we can't force an unshare of the fs because > of at least Chrome: > https://lore.kernel.org/lkml/86CE201B-5632-4BB7-BCF6-7CB2C2895409@chromium.org/ > > Cc: Eric Biederman > Cc: linux-fsdevel@vger.kernel.org > Signed-off-by: Kees Cook > --- Acked-by: Christian Brauner (Microsoft)