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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 4543EC433B4 for ; Wed, 7 Apr 2021 16:33:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D45646128D for ; Wed, 7 Apr 2021 16:33:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D45646128D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E4A566B0072; Wed, 7 Apr 2021 12:33:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DFAB66B0073; Wed, 7 Apr 2021 12:33:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C766E6B007D; Wed, 7 Apr 2021 12:33:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0240.hostedemail.com [216.40.44.240]) by kanga.kvack.org (Postfix) with ESMTP id A7EE06B0072 for ; Wed, 7 Apr 2021 12:33:51 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 636D44DC3 for ; Wed, 7 Apr 2021 16:33:51 +0000 (UTC) X-FDA: 78006117462.18.8A92524 Received: from mail-yb1-f176.google.com (mail-yb1-f176.google.com [209.85.219.176]) by imf15.hostedemail.com (Postfix) with ESMTP id 18C32A0003A2 for ; Wed, 7 Apr 2021 16:33:49 +0000 (UTC) Received: by mail-yb1-f176.google.com with SMTP id i144so20793495ybg.1 for ; Wed, 07 Apr 2021 09:33:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=0lwsn0u8IqnICGvyAtiBlcyUYYkzwv4EZu9XbSKhZrg=; b=TWEJp7OutTUnO1JIFD74hY9u3yciqYCtgTdf56knITi6CkAmDtCZZXDMRNzmbxnwrh bLHAUsZyRk7YcRxxvH0CTDeN94hfbeaxsbuMc3jFOmszMsXYQ6t7s+4XYsSSQoYD0XMm g0xESiZe/ihc/ZUZhY1zfewcJSN5cKnL5I05FBSo4ZfGoR6AO9Fbk6mSYP5PU7/ek/WR /2DTrzU+zBKENUWBy14uNSqqlSy3Bj83K+hkINV0y2/4b3cQXOJasAoO0gzC31WUmfgX sK/EqdltijimdWmmrGTeeKImYGQK5Mukh16EitOpxY/MQh11Uz77zdL7q/9GmnfUQp66 gw+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=0lwsn0u8IqnICGvyAtiBlcyUYYkzwv4EZu9XbSKhZrg=; b=UJqbDU7A2VX0hzzQjZFsXe93eIdBSSqgRFfSINbRUrEzSmgmEriSfG/7vDGQ61sy3K swFXZ3oI8KoqaxlhFTjRGvm3NAtacUJj9F6c1XbUytAbD8yJOUaqhniHH3sp9dIFKfft 5CMa4suFG9mRtmWKZlAdQRM5hRN2TzFsbjRqj9trgIm9LM7/1edpbdi5aN2MHN4Haykf yQsbcawp66enEb61sYFUh6l+/5pga26v6tINKyHjXO0uEvvS0Pn9tsmqd54TnkelEral CV9PvgPPzlfeoV3P1NO7uEaxIp+bM/m/qQv5axmtTrM9Fdd1U+5xxsq3/GExZCYsLcfI fp6w== X-Gm-Message-State: AOAM533QewSlI/15jVK6LxaH0OCZQhS/zUpWFPbkznZSe4MgOJQcQS1k ZbVckKLjJjkygLfOrRPBuNYA5FsP2IG8oGnNhC6YlQ== X-Google-Smtp-Source: ABdhPJxMcZIjSk5SxemHmmgHhUXGk613blsBNSxX/7m9hmiZI2uoGUA/6Ddd825mHLMNN1EViUgxwXpkg1G7eOH3h+0= X-Received: by 2002:a25:c801:: with SMTP id y1mr5843563ybf.250.1617813224849; Wed, 07 Apr 2021 09:33:44 -0700 (PDT) MIME-Version: 1.0 References: <20210401181741.168763-1-surenb@google.com> In-Reply-To: From: Suren Baghdasaryan Date: Wed, 7 Apr 2021 09:33:34 -0700 Message-ID: Subject: Re: [PATCH 0/5] 4.14 backports of fixes for "CoW after fork() issue" To: Linus Torvalds Cc: Vlastimil Babka , Peter Xu , stable , Greg Kroah-Hartman , Jann Horn , Kirill Tkhai , Shaohua Li , Nadav Amit , Linux-MM , Linux Kernel Mailing List , Android Kernel Team , Andrea Arcangeli , David Hildenbrand , Jason Gunthorpe Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 18C32A0003A2 X-Stat-Signature: wdcifq8kx8wu8k9jqtc7dmupbu9yqse5 Received-SPF: none (google.com>: No applicable sender policy available) receiver=imf15; identity=mailfrom; envelope-from=""; helo=mail-yb1-f176.google.com; client-ip=209.85.219.176 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617813229-395764 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Apr 7, 2021 at 9:07 AM Linus Torvalds wrote: > > On Wed, Apr 7, 2021 at 6:22 AM Vlastimil Babka wrote: > > > > 1) Ignore the issue (outside of Android at least). The security model of zygote > > is unusual. Where else a parent of fork() doesn't trust the child, which is the > > same binary? > > Agreed. I think this is basically an android-only issue (with > _possibly_ some impact on crazy "pin-and-fork" loads), and doesn't > necessarily merit a backport at all. > > If Android people insist on using very old kernels, knowing that they > do things that are questionable with those old kernels, at some point > it's just _their_ problem. We don't really insist on using old kernels but rather we are stuck with them for some time. Trying my hand at backporting the patchsets Peter mentioned proved this to be far from easy with many dependencies. Let me look into Vlastimil's suggestion to backport only 17839856fd58 and it sounds like 5.4 already followed that path. Thanks for all the information! Suren. > > Linus > > -- > To unsubscribe from this group and stop receiving emails from it, send an email to kernel-team+unsubscribe@android.com. >