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=-15.1 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL autolearn=ham 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 45A11C18DF5 for ; Tue, 20 Nov 2018 13:23:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08D7120851 for ; Tue, 20 Nov 2018 13:23:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="hIInteTa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08D7120851 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727586AbeKTXwa (ORCPT ); Tue, 20 Nov 2018 18:52:30 -0500 Received: from mail-it1-f194.google.com ([209.85.166.194]:35741 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725843AbeKTXw3 (ORCPT ); Tue, 20 Nov 2018 18:52:29 -0500 Received: by mail-it1-f194.google.com with SMTP id v11so3453854itj.0 for ; Tue, 20 Nov 2018 05:23:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=L/LJKDb9qV1jIIWGz4LuixjhEUZ2sxe7NOqkJbx6PBg=; b=hIInteTaCMZJk5WLIa8KABCK/nWUf3iSRGXl1ktYDwta8BSYbHLXICFZ8uqSm0Hpuw ReBCJiuMHIhwi+AhOy7syqidRg5+VZJP//spln7lNEHVRrmWiChmC13gA6uM0/HcJVRc FUmcOYO3pElKoVX3ZBgx2LxVVEIjzzHCZ7FOX+pjV0anXSQAVoYkcqFJPAHrPX1mX6CG eziaIPMxgPNIm2970Gd/jN8PxwhYqn9xXuwmYyiPSMikCF8JCeh0037kEBqoL6YXPjoZ 7WSD+Byh/uYWpTXBtlNiTArLE1cWSe1BcApsfy1JN4soe5E4c/j6u1VTrFa1m01E8Jse fDlw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=L/LJKDb9qV1jIIWGz4LuixjhEUZ2sxe7NOqkJbx6PBg=; b=lUImzSsLk+4MCl8tTfhP815K8iLmL4Lf5p9iXSK0GAlYCcKIVuyakb3RG/uxegrzkO 5gwYR2CJZ0lf0QXPHkrY4yy2wXf2Y/X5Qv8LOpjdyCXVg6kkBInbhIHKSADL3FFlVu9E xBmJGDUof3f5wTwqNk8Xot83FplUwu5In764c7W+i6RrX4qhnywqNuQA9GfKuHEIazxt Lt9ETLvcpcyD6a/OV4boqs19/7rr5FvWu3DOAEQPHtUi7vmTmCUh1gB49WVX1yS6b6OJ xxuHeKxvFIik6W+EK5ayxgyWBh2ZTN+7Unydr7WeW55kZxGitdGh1vWRCjjB/mfpqH9S 9quw== X-Gm-Message-State: AGRZ1gI4umTKtH+ub8vWUC3udRLnBqh6LLdrkbPaNLgIyWkkylCQ+PgE NTy1DnJYBw/H/wjpm50zTZJsccnEgvVW6JGbpAwZDA== X-Google-Smtp-Source: AFSGD/XywZkyW34t2+fMIxYmnSZqHtVDXwVqgoDigHQLIzgwf/bii5aN0YOnU9Z3u/zifx6UCryKKxwpZEgP10ZGGQs= X-Received: by 2002:a05:660c:f94:: with SMTP id x20mr1869575itl.144.1542720201161; Tue, 20 Nov 2018 05:23:21 -0800 (PST) MIME-Version: 1.0 Received: by 2002:a02:b003:0:0:0:0:0 with HTTP; Tue, 20 Nov 2018 05:23:00 -0800 (PST) In-Reply-To: References: <000000000000222b58057a7d9f39@google.com> <9d9ad7f2781bf15af4bd6ccc9feee35c7cd17979.camel@kernel.org> <87bm6svhhl.fsf@notabene.neil.brown.name> <87bm6pewnm.fsf@notabene.neil.brown.name> <20181117140356.GA29895@fieldses.org> From: Dmitry Vyukov Date: Tue, 20 Nov 2018 14:23:00 +0100 Message-ID: Subject: Re: KASAN: use-after-free Read in locks_delete_block To: Jeff Layton Cc: Bruce Fields , NeilBrown , syzbot , linux-fsdevel , LKML , syzkaller-bugs , Al Viro Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 20, 2018 at 12:08 PM, Jeff Layton wrote: > On Tue, 2018-11-20 at 07:57 +0100, Dmitry Vyukov wrote: >> On Sat, Nov 17, 2018 at 3:03 PM, Bruce Fields wrote: >> > On Sat, Nov 17, 2018 at 08:33:27AM -0500, Jeff Layton wrote: >> > > Thanks for the explanation, Dmitry. I've added the tag to the patch in >> > > my tree. It should show up in linux-next soon. >> > > >> > > I still find it a little misleading to say that syzbot reported a bug >> > > when it actually found a bug inside an earlier version of the patch, but >> > > I'll just learn to get over it. >> > >> > The usual tag for someone that found a bug in an earlier version of a >> > patch would be Reviewed-by:. Is there any reason we can't use that >> > here? The "syzbot+..." email should be enough on its own, I can't see a >> > reason why their scripts would need to require a particular tag. Or >> > maybe we could use Tested-by:, or some other tag made up for this case? >> > >> > I do worry that someone who sees "Reported-by:..." might for example >> > mistakenly assume that it would help to backport that patch if they see >> > a similar-looking oops. >> >> I see. It may also be picked by scripts that detects patches that need >> to be backported to stable because of the "Reported-by: syzbot" tag. >> This is somewhat unfortunate. >> >> There is no problem parsing another tag on syzbot side. Does Tested-by >> look good to you? If it found a bug in the patch and then it was >> fixed, Tested-by looks reasonable. And we also detect >> Reported-and-tested-by already because that's what syzbot suggests >> after it tested a proposed fix for a bug. >> >> I am somewhat concerned how to spread this information across all >> kernel developers. There is effectively no way to do this. We can't >> expect people to read docs, they generally don't. I guess I just >> document this at "See https://goo.gl/tpsmEJ for more information" and >> then we can point other people there if/when this concern pops up >> again. > > Tested-by sounds like it might be a reasonable fit. I'll change the > patch in my tree to read that way. Turns out this already works (we did not check exact tag, just search for the right email with a hash). So I added a test for Tested-by tag and extended the docs: https://github.com/google/syzkaller/commit/9aca6b5240809308d9078a0a0f0707512c5b0220