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=-8.3 required=3.0 tests=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 295D4C2D0BF for ; Fri, 13 Dec 2019 09:05:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 001D5206D8 for ; Fri, 13 Dec 2019 09:05:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="B7sZGUc8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726735AbfLMJFZ (ORCPT ); Fri, 13 Dec 2019 04:05:25 -0500 Received: from mail-qk1-f194.google.com ([209.85.222.194]:42093 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726313AbfLMJFY (ORCPT ); Fri, 13 Dec 2019 04:05:24 -0500 Received: by mail-qk1-f194.google.com with SMTP id z14so1122899qkg.9 for ; Fri, 13 Dec 2019 01:05:23 -0800 (PST) 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=h8q9Wm8aWVtXxqEWvO1buQUPSO+i3sBYZTuEX4LXTnk=; b=B7sZGUc8JMAembbK0ltQ8ygFW5+jdF27WXh6jv4xGx0+SQH8pPq60FfC1rxPPNFSWM ynlfSsLwdeE44UAoRgY5Wx9AdrNkg6MAI+FNvmEjDg5BNR10MCd4Hmh/jdZg6Y8Uxjqg iKcCDOf3npPlr60ooocTqEfv2KvAicMmKNyP6kZEhZ12i3gnz7yBR881B8lImFTrNiC+ jGkt+YX8msoEdB9UzmMCcQ6/1jXSFAtsj3Y3fgwEPt+oPfu4WbMR4KoJmdKkTYxbt10Z zVx5EYTTNftyuxVnD1xxZi9Lclm/Ka5x1XOXojG35QNi51E25KSUGsdkeKK9W5K9103I pswQ== 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=h8q9Wm8aWVtXxqEWvO1buQUPSO+i3sBYZTuEX4LXTnk=; b=qIY1Y1Nttvr3wUZlJ37Wzo4Coekgea7JfEbPNotUAzjsH6X2F+6OFFEi9GVooq4aoZ 9VfYOlYUXWw/B2ryCd3jgYT3DdhGI8WtjL3RBj0Rh/BJhoPV9/vuJjsgloxvc//bsgpj a9ckpNdJpzcv+9SKJrchrElkkxBF9tVF039FQy5QmhAFjDc8h9gDyqV4pAEPS5htRzeK fNtPx5lMgpLzs2Ts6fdyw1Z5JlK5s/CeBD1njxVd78kvIe7iHiq/HsqoLuISVfOttD5w jQSEr/K+kOzx/T2N8D0rOo9jW11lqdAFxILQEpVvJTkqXitVv2ratZE56rRYXNGP7HWp FYhQ== X-Gm-Message-State: APjAAAUqxq56StYHjI5wenOHfaX5vi1Rej7cvR5gRnM4EVK3kzqBzvLN 5w2Ji2IY5/E+ynbtU727n9DfoKAx/hoGEJ6z55mCfQ== X-Google-Smtp-Source: APXvYqwucBZ+KePWjNxfbIQ0iGzvUQbCnGpqVbIzovLpVsu/xVnANjMnnkecD2sqjMx92nOXSoJwmkoHly3Hn7ULSJo= X-Received: by 2002:a37:e312:: with SMTP id y18mr12834178qki.250.1576227922838; Fri, 13 Dec 2019 01:05:22 -0800 (PST) MIME-Version: 1.0 References: <00000000000044a65205994a7e13@google.com> <00000000000003cc8505994f9036@google.com> <20191212105754.GC1476206@kroah.com> In-Reply-To: <20191212105754.GC1476206@kroah.com> From: Dmitry Vyukov Date: Fri, 13 Dec 2019 10:05:11 +0100 Message-ID: Subject: Re: BUG: unable to handle kernel NULL pointer dereference in mem16_serial_out To: Greg KH Cc: syzbot , Andy Shevchenko , asierra@xes-inc.com, Jonathan Corbet , ext-kimmo.rautkoski@vaisala.com, Jiri Slaby , kai heng feng , Linux API , "open list:DOCUMENTATION" , LKML , linux-serial , mika.westerberg@linux.intel.com, paulburton@kernel.org, Peter Hurley , sr@denx.de, syzkaller-bugs , Masahiro Yamada , yegorslists@googlemail.com 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 Thu, Dec 12, 2019 at 11:57 AM Greg KH wrote: > > On Mon, Dec 09, 2019 at 05:38:01PM -0800, syzbot wrote: > > syzbot has bisected this bug to: > > > > commit bd94c4077a0b2ecc35562c294f80f3659ecd8499 > > Author: Masahiro Yamada > > Date: Wed Oct 28 03:46:05 2015 +0000 > > > > serial: support 16-bit register interface for console > > That would be because that is when this function was added to the kernel > :) > > Again, you are asking the kernel to write to a bad place in memory, and > then crash when that happens. That sounds like the correct > functionality to me... This looks like: #syz dup: BUG: unable to handle kernel NULL pointer dereference in mem_serial_out Let's continue in that thread.