Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753089AbeADONY (ORCPT + 1 other); Thu, 4 Jan 2018 09:13:24 -0500 Received: from mail-pf0-f194.google.com ([209.85.192.194]:43373 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752741AbeADONX (ORCPT ); Thu, 4 Jan 2018 09:13:23 -0500 X-Google-Smtp-Source: ACJfBosvMKIlVC63USRW7JoBQRcpMVY5WwbJ9ml6Im7Xeks6GLthwoUG0q1Tk8QIgNxiK45DKkLmbo7f4YkKRYtVM9o= MIME-Version: 1.0 In-Reply-To: <20180104140627.GB17490@kroah.com> References: <20180104140627.GB17490@kroah.com> From: Dmitry Vyukov Date: Thu, 4 Jan 2018 15:13:01 +0100 Message-ID: Subject: Re: WARNING in ion_ioctl To: Greg KH Cc: syzbot , arve@android.com, devel@driverdev.osuosl.org, Laura Abbott , LKML , maco@android.com, sumit.semwal@linaro.org, syzkaller-bugs@googlegroups.com, tkjos@android.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Thu, Jan 4, 2018 at 3:06 PM, Greg KH wrote: > On Thu, Jan 04, 2018 at 05:57:01AM -0800, syzbot wrote: >> Hello, >> >> syzkaller hit the following crash on >> 71ee203389f7cb1c1927eab22b95baa01405791c >> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master >> compiler: gcc (GCC) 7.1.1 20170620 >> .config is attached >> Raw console output is attached. >> C reproducer is attached >> syzkaller reproducer is attached. See https://goo.gl/kgGztJ >> for information about syzkaller reproducers >> >> >> IMPORTANT: if you fix the bug, please add the following tag to the commit: >> Reported-by: syzbot+fa2d5f63ee5904a0115a@syzkaller.appspotmail.com >> It will help syzbot understand when the bug is fixed. See footer for >> details. >> If you forward the report, please keep this part and the footer. >> >> audit: type=1400 audit(1514734723.062:7): avc: denied { map } for >> pid=3502 comm="syzkaller809746" path="/root/syzkaller809746698" dev="sda1" >> ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 >> tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 >> WARNING: CPU: 0 PID: 3502 at drivers/staging/android/ion/ion-ioctl.c:73 >> ion_ioctl+0x2db/0x380 drivers/staging/android/ion/ion-ioctl.c:73 >> Kernel panic - not syncing: panic_on_warn set ... > > This is to be expected when you pass in a crappy ion ioctl structure. > > So don't do that :) > > Yeah, it's a harsh warning, but I think the userspace developers like it > to ensure they got their implementation correct. > > After the warning is thrown, all keeps working just fine. Hi Greg, Or, don't do WARNINGs on EINVAL and do pr_warn instead, as useful but also enables automated kernel testing with non-tainted reports, which is kinda a useful property.