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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B4A51C54FD3 for ; Wed, 25 Mar 2020 15:42:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 89F902073E for ; Wed, 25 Mar 2020 15:42:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 89F902073E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ubuntu.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 34FC66B0010; Wed, 25 Mar 2020 11:42:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2FFF36B0032; Wed, 25 Mar 2020 11:42:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1C7596B0036; Wed, 25 Mar 2020 11:42:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0048.hostedemail.com [216.40.44.48]) by kanga.kvack.org (Postfix) with ESMTP id F0C376B0010 for ; Wed, 25 Mar 2020 11:42:11 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id D963D805DE for ; Wed, 25 Mar 2020 15:42:11 +0000 (UTC) X-FDA: 76634300862.25.jar70_87885efeb4b54 X-HE-Tag: jar70_87885efeb4b54 X-Filterd-Recvd-Size: 3051 Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by imf09.hostedemail.com (Postfix) with ESMTP for ; Wed, 25 Mar 2020 15:42:11 +0000 (UTC) Received: from ip5f5bf7ec.dynamic.kabel-deutschland.de ([95.91.247.236] helo=wittgenstein) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jH89x-0002aK-CF; Wed, 25 Mar 2020 15:41:37 +0000 Date: Wed, 25 Mar 2020 16:41:33 +0100 From: Christian Brauner To: Bernd Edlinger Cc: Greg Kroah-Hartman , Kirill Tkhai , "Eric W. Biederman" , Kees Cook , Jann Horn , Jonathan Corbet , Alexander Viro , Andrew Morton , Alexey Dobriyan , Thomas Gleixner , Oleg Nesterov , Frederic Weisbecker , Andrei Vagin , Ingo Molnar , "Peter Zijlstra (Intel)" , Yuyang Du , David Hildenbrand , Sebastian Andrzej Siewior , Anshuman Khandual , David Howells , James Morris , Shakeel Butt , Jason Gunthorpe , Christian Kellner , Andrea Arcangeli , Aleksa Sarai , "Dmitry V. Levin" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "stable@vger.kernel.org" , "linux-api@vger.kernel.org" Subject: Re: [PATCH v6 10/16] kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve Message-ID: <20200325154133.5gcxkpnnbyasqvl6@wittgenstein> References: <077b63b7-6f5e-aa8e-bf96-a586b481cc46@hotmail.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Mar 20, 2020 at 09:27:05PM +0100, Bernd Edlinger wrote: > This changes kcmp_epoll_target to use the new exec_update_mutex > instead of cred_guard_mutex. > > This should be safe, as the credentials are only used for reading, > and furthermore ->mm and ->sighand are updated on execve, > but only under the new exec_update_mutex. > > Signed-off-by: Bernd Edlinger Acked-by: Christian Brauner