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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 E35F7C47253 for ; Fri, 1 May 2020 11:16:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A128620787 for ; Fri, 1 May 2020 11:16:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A128620787 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3A2918E0017; Fri, 1 May 2020 07:16:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 353D18E0001; Fri, 1 May 2020 07:16:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 268BC8E0017; Fri, 1 May 2020 07:16:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0175.hostedemail.com [216.40.44.175]) by kanga.kvack.org (Postfix) with ESMTP id 0F71D8E0001 for ; Fri, 1 May 2020 07:16:51 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C188B180AD80F for ; Fri, 1 May 2020 11:16:50 +0000 (UTC) X-FDA: 76767897780.08.wheel66_75e83bbbd7c35 X-HE-Tag: wheel66_75e83bbbd7c35 X-Filterd-Recvd-Size: 6377 Received: from out03.mta.xmission.com (out03.mta.xmission.com [166.70.13.233]) by imf13.hostedemail.com (Postfix) with ESMTP for ; Fri, 1 May 2020 11:16:50 +0000 (UTC) Received: from in02.mta.xmission.com ([166.70.13.52]) by out03.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jUTeu-0007G0-HZ; Fri, 01 May 2020 05:16:44 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1jUTet-0006Wp-Mr; Fri, 01 May 2020 05:16:44 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Greg Ungerer Cc: Linus Torvalds , Russell King - ARM Linux admin , Jann Horn , Nicolas Pitre , Andrew Morton , Christoph Hellwig , Linux Kernel Mailing List , Linux-MM , linux-fsdevel , Alexander Viro , Oleg Nesterov , Linux ARM , Mark Salter , Aurelien Jacquiot , linux-c6x-dev@linux-c6x.org, Yoshinori Sato , Rich Felker , Linux-sh list References: <20200429214954.44866-1-jannh@google.com> <20200429215620.GM1551@shell.armlinux.org.uk> <31196268-2ff4-7a1d-e9df-6116e92d2190@linux-m68k.org> <87imhgyeqt.fsf@x220.int.ebiederm.org> <9dd76936-0009-31e4-d869-f64d01886642@linux-m68k.org> Date: Fri, 01 May 2020 06:13:24 -0500 In-Reply-To: <9dd76936-0009-31e4-d869-f64d01886642@linux-m68k.org> (Greg Ungerer's message of "Fri, 1 May 2020 15:44:03 +1000") Message-ID: <87wo5vx60b.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1jUTet-0006Wp-Mr;;;mid=<87wo5vx60b.fsf@x220.int.ebiederm.org>;;;hst=in02.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18Ja6ZhJX6gmVl5+uqwyRJT9MkgBLIzECc= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH v2 0/5] Fix ELF / FDPIC ELF core dumping, and use mmap_sem properly in there X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) 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: Greg Ungerer writes: > On 1/5/20 5:07 am, Eric W. Biederman wrote: >> Linus Torvalds writes: >> >>> On Thu, Apr 30, 2020 at 7:10 AM Greg Ungerer wrote: >> >>>>> Most of that file goes back to pre-git days. And most of the commits >>>>> since are not so much about binfmt_flat, as they are about cleanups or >>>>> changes elsewhere where binfmt_flat was just a victim. >>>> >>>> I'll have a look at this. >>> >>> Thanks. >>> >>>> Quick hack test shows moving setup_new_exec(bprm) to be just before >>>> install_exec_creds(bprm) works fine for the static binaries case. >>>> Doing the flush_old_exec(bprm) there too crashed out - I'll need to >>>> dig into that to see why. >>> >>> Just moving setup_new_exec() would at least allow us to then join the >>> two together, and just say "setup_new_exec() does the credential >>> installation too". >> >> But it is only half a help if we allow failure points between >> flush_old_exec and install_exec_creds. >> >> Greg do things work acceptably if install_exec_creds is moved to right >> after setup_new_exec? (patch below) > > Yes, confirmed. Worked fine with that patch applied. Good. Thank you. That is what we need for other cleanups. All three of those together. >> This is what I was thinking about applying. >> >> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c >> index 831a2b25ba79..1a1d1fcb893f 100644 >> --- a/fs/binfmt_flat.c >> +++ b/fs/binfmt_flat.c >> @@ -541,6 +541,7 @@ static int load_flat_file(struct linux_binprm *bprm, >> /* OK, This is the point of no return */ >> set_personality(PER_LINUX_32BIT); >> setup_new_exec(bprm); >> + install_exec_creds(bprm); >> } >> /* >> @@ -963,8 +964,6 @@ static int load_flat_binary(struct linux_binprm *bprm) >> } >> } >> - install_exec_creds(bprm); >> - >> set_binfmt(&flat_format); >> #ifdef CONFIG_MMU Eric