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=-7.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 4FC65C43441 for ; Sat, 24 Nov 2018 21:20:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 09C0A20820 for ; Sat, 24 Nov 2018 21:20:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 09C0A20820 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=vmware.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 S1726464AbeKYIJn (ORCPT ); Sun, 25 Nov 2018 03:09:43 -0500 Received: from mail-wr1-f66.google.com ([209.85.221.66]:43226 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726119AbeKYIJn (ORCPT ); Sun, 25 Nov 2018 03:09:43 -0500 Received: by mail-wr1-f66.google.com with SMTP id r10so15230638wrs.10; Sat, 24 Nov 2018 13:20:23 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=9K8bOxJv3ckrE+VIJSJ0LJjb71TbkrvWZ4pLGxtphHc=; b=Cbe6dkarU+O/cua6ilKuyR+rOURdSi1DvAL4Tr1W5BAdgeZhsga+m4wSTRLNdmn93Z FDUkaiT7svA1NfC7IM42VnbXwFcWrFymtqXYS7S9k14AsPfZtRKc1pF6K1FVOmU/ZsLJ qj9Fyt9QiHT4rbG5l3+G/BqGYc/1YB792HPKDgNAQY2UQWe74ZgnN14cVOvmgR+yD5yY MCSmtr/RWrweNkqL5BvqQKf66sXJXeAFbNZ9IBgpC7vxkxsZoF5F56MvaNqDRsI1OmxB jfQSN4iwkqILvlL3Xh1CYmjYBFsfbj167+D0sqVLFNIhO3RbUT6s+Lw1EPUgzC/1ZPMd K33g== X-Gm-Message-State: AA+aEWaB8Nfxhor0XEmOQLg3r1FNYjiR+1uUbe0tw5e6cTgIVADxZLc0 UrGwUYNPt5Szr+GzK/SK/A== X-Google-Smtp-Source: AFSGD/WqNkFtbOH7y/HzalMZe7Yvam1dugRV4ZQxlS1S0fd6UngnKujNzFqq90ZwWyoPxE8SSJU/bA== X-Received: by 2002:a5d:5351:: with SMTP id t17mr18209302wrv.288.1543094422717; Sat, 24 Nov 2018 13:20:22 -0800 (PST) Received: from box ([213.145.108.55]) by smtp.gmail.com with ESMTPSA id a12sm22244650wrm.45.2018.11.24.13.20.21 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 24 Nov 2018 13:20:21 -0800 (PST) Date: Sat, 24 Nov 2018 23:20:14 +0200 From: Slavomir Kaslev To: Al Viro Cc: syzbot , davem@davemloft.net, gregkh@linuxfoundation.org, kgraul@linux.ibm.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, stranche@codeaurora.org, syzkaller-bugs@googlegroups.com Subject: Re: WARNING in csum_and_copy_to_iter Message-ID: <20181124211918.GA20435@box> References: <0000000000001ecaa1057b6e4489@google.com> <20181124200357.GC2217@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181124200357.GC2217@ZenIV.linux.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 24, 2018 at 08:03:57PM +0000, Al Viro wrote: > On Sat, Nov 24, 2018 at 11:40:03AM -0800, syzbot wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: edeca3a769ad Merge tag 'sound-4.20-rc4' of git://git.kerne.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=12bee26d400000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=73e2bc0cb6463446 > > dashboard link: https://syzkaller.appspot.com/bug?extid=ce18da013d76d837144d > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15ccd1f5400000 > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+ce18da013d76d837144d@syzkaller.appspotmail.com > > Caused by commit 95506588d2c1d72ca29adef8ae9bf771bcfb4ced > Author: Slavomir Kaslev > Date: Fri Nov 16 11:27:53 2018 +0200 > > socket: do a generic_file_splice_read when proto_ops has no splice_read > > exposing all ->recvmsg() instances to pipe-backed iov_iter as possible destination. > It's not all that hard to fix (I'll probably have a candidate patch by tonight, > it's just a matter of adding the only missing primitive), but... shouldn't that > patch have sat in -next for at least some testing first? Because it's very > easy to reproduce - splice from e.g. UDP socket will step into it. Sure, the > sky is not falling (unless you set panic-on-WARN, that is); the damn thing > would've failed anyway, but... My bad for not sending the patch tagged as net-next, feel free to revert it.