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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 8F242C433ED for ; Sat, 17 Apr 2021 03:19:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7395F6101E for ; Sat, 17 Apr 2021 03:19:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235671AbhDQDUW (ORCPT ); Fri, 16 Apr 2021 23:20:22 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:57035 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234999AbhDQDUQ (ORCPT ); Fri, 16 Apr 2021 23:20:16 -0400 Received: from fsav103.sakura.ne.jp (fsav103.sakura.ne.jp [27.133.134.230]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 13H3J5UU012332; Sat, 17 Apr 2021 12:19:05 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav103.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav103.sakura.ne.jp); Sat, 17 Apr 2021 12:19:05 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav103.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 13H3J55V012327 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Sat, 17 Apr 2021 12:19:05 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: [syzbot] unexpected kernel reboot (4) To: Andrey Konovalov , Dmitry Vyukov Cc: syzbot , LKML , syzkaller-bugs , "open list:HID CORE LAYER" References: <000000000000301a4d05bfe14b8f@google.com> From: Tetsuo Handa Message-ID: <55f68dce-77e8-b142-0822-fca14b13d4bd@i-love.sakura.ne.jp> Date: Sat, 17 Apr 2021 12:19:06 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On 2021/04/15 0:39, Andrey Konovalov wrote: > On Wed, Apr 14, 2021 at 7:45 AM Dmitry Vyukov wrote: >> The reproducer connects some USB HID device and communicates with the driver. >> Previously we observed reboots because HID devices can trigger reboot >> SYSRQ, but we disable it with "CONFIG_MAGIC_SYSRQ is not set". >> How else can a USB device reboot the machine? Is it possible to disable it? >> I don't see any direct includes of in drivers/usb/* > > This happens when a keyboard sends the Ctrl+Alt+Del sequence, see > fn_boot_it()->ctrl_alt_del() in drivers/tty/vt/keyboard.c. > Regarding ctrl_alt_del() problem, doing sh -c 'echo 0 > /proc/sys/kernel/ctrl-alt-del; echo $$ > /proc/sys/kernel/cad_pid' as root before start fuzzing might help. Also, with the command above, reproducer still triggers suspend operation which freezes userspace processes. This could possibly be one of causes for no output / lost connections. Try disabling freeze/suspend related configs? [ 60.881255][ T6280] usb 5-1: new high-speed USB device number 2 using dummy_hcd [ 61.260648][ T6280] usb 5-1: config 0 interface 0 altsetting 0 endpoint 0x81 has an invalid bInterval 0, changing to 7 [ 61.274056][ T6280] usb 5-1: New USB device found, idVendor=0926, idProduct=3333, bcdDevice= 0.40 [ 61.284700][ T6280] usb 5-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 [ 61.289556][ T6280] usb 5-1: config 0 descriptor?? [ 61.780871][ T6280] keytouch 0003:0926:3333.0002: fixing up Keytouch IEC report descriptor [ 61.792015][ T6280] input: HID 0926:3333 as /devices/platform/dummy_hcd.0/usb5/5-1/5-1:0.0/0003:0926:3333.0002/input/input5 [ 61.871612][ T6280] keytouch 0003:0926:3333.0002: input,hidraw1: USB HID v0.00 Keyboard [HID 0926:3333] on usb-dummy_hcd.0-1/input0 [ 62.137706][ T6847] PM: suspend entry (s2idle) [ 62.147914][ T6847] Filesystems sync: 0.007 seconds [ 62.152031][ T6847] Freezing user space processes ... (elapsed 0.003 seconds) done. [ 62.158369][ T6847] OOM killer disabled. [ 62.159673][ T6847] Freezing remaining freezable tasks ... (elapsed 0.003 seconds) done. [ 62.167440][ T6847] vhci_hcd vhci_hcd.15: suspend vhci_hcd [ 62.169569][ T6847] vhci_hcd vhci_hcd.14: suspend vhci_hcd [ 62.171562][ T6847] vhci_hcd vhci_hcd.13: suspend vhci_hcd [ 62.173500][ T6847] vhci_hcd vhci_hcd.12: suspend vhci_hcd [ 62.175740][ T6847] vhci_hcd vhci_hcd.11: suspend vhci_hcd [ 62.177677][ T6847] vhci_hcd vhci_hcd.10: suspend vhci_hcd [ 62.179725][ T6847] vhci_hcd vhci_hcd.9: suspend vhci_hcd [ 62.181602][ T6847] vhci_hcd vhci_hcd.8: suspend vhci_hcd [ 62.183681][ T6847] vhci_hcd vhci_hcd.7: suspend vhci_hcd [ 62.185594][ T6847] vhci_hcd vhci_hcd.6: suspend vhci_hcd [ 62.187552][ T6847] vhci_hcd vhci_hcd.5: suspend vhci_hcd [ 62.189566][ T6847] vhci_hcd vhci_hcd.4: suspend vhci_hcd [ 62.191767][ T6847] vhci_hcd vhci_hcd.3: suspend vhci_hcd [ 62.193657][ T6847] vhci_hcd vhci_hcd.2: suspend vhci_hcd [ 62.195634][ T6847] vhci_hcd vhci_hcd.1: suspend vhci_hcd [ 62.197430][ T6847] vhci_hcd vhci_hcd.0: suspend vhci_hcd [ 62.249881][ T8] mptbase: ioc0: pci-suspend: pdev=0xffff888005495000, slot=0000:00:10.0, Entering operating state [D0]