From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f43.google.com (mail-lf1-f43.google.com [209.85.167.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2EB92C80 for ; Thu, 9 Dec 2021 18:22:33 +0000 (UTC) Received: by mail-lf1-f43.google.com with SMTP id b1so13556097lfs.13 for ; Thu, 09 Dec 2021 10:22:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :references:from:in-reply-to:content-transfer-encoding; bh=QxWGzwiQK1H9THXhhSK1MS0BSvGH8EGX6peXdw0hns0=; b=O4VpfJBV9bqM4uCF3IFZ9LswiKvtA6fnK9DxckWyYKxCNIrMSW8y8rbDnYNrHlxAOK Mhq8P2Xb8G4zTnv5dn1HrTkdla0a6xhg+iZePUVCKUM8QNBY/gNzJJfUbsYBa/DDaCOj sjSuzKc9JStNjjN3nz8MOwjTt68i3YPRQZJJRcxtB/aQijcI6QInAE8kVvOOdgQgrDa3 nnUGFST9r7CrW32JHiMNxpuMnBqeEU/a1xdep1bOBuGRAzQSUDSvbcDcCrkMTz0b1iGo bgoopPQ+V1L0hW/2ETX4hjay8g+fVhvKZQlnugDZfEWwYTDRMTNwik7cNu5k5OtEnsNn /IxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:references:from:in-reply-to :content-transfer-encoding; bh=QxWGzwiQK1H9THXhhSK1MS0BSvGH8EGX6peXdw0hns0=; b=gpH6cV3No68xhkbfGcq7z68C8RnDpty6s677tEOY7nwwIC5VwXGn5fTEymrvBO1pBD r1S84LW5Kk45iTeshrhFg8HWFF7eX08J1vqag4LPYl9gbR9HCWPa4CmJebuK/tDZXapO qLFKI/Apq53CETVzbwBmCo7/8YM7Hw82uZs3te9zYwGqAKvoiroxsP1jGi87q6XjI4TU NTVNoqKjhD4HTZL8sbyYQ7un11bvPq3r6pXusVDoa54ITnsS/ulxY5s3N/pjBPxHsQQy PEo+Jlr6JXF37osDs8PkplfdeH9x1cK8s1k2hVZY9/6KaarQjOYx5y7QB5R/+qP82IFe 7qeQ== X-Gm-Message-State: AOAM5309VzF95rVBkG4PJ4PO8FDAUjdVSaz5Gs5s9z7hXPhRMLIhtUX4 CVYRYEULEvM5s+26gnS7Xh4= X-Google-Smtp-Source: ABdhPJxdnwXbD+UJp67OF+eJClo0r5F/dqDG4cmKZ1p7TKeK+wLIx2/o6A+8ucS2M3od9a+BtNKtLQ== X-Received: by 2002:a05:6512:3f27:: with SMTP id y39mr7531588lfa.675.1639074152039; Thu, 09 Dec 2021 10:22:32 -0800 (PST) Received: from [192.168.1.11] ([94.103.229.236]) by smtp.gmail.com with ESMTPSA id n12sm58025lfq.3.2021.12.09.10.22.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 09 Dec 2021 10:22:31 -0800 (PST) Message-ID: <0c116de3-1e55-f888-2b4f-285484082085@gmail.com> Date: Thu, 9 Dec 2021 21:22:29 +0300 Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.2 Subject: Re: [syzbot] INFO: task hung in r871xu_dev_remove Content-Language: en-US To: syzbot , Larry.Finger@lwfinger.net, florian.c.schilhabel@googlemail.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com References: <00000000000042e11e05d2b0b39b@google.com> From: Pavel Skripkin In-Reply-To: <00000000000042e11e05d2b0b39b@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/9/21 09:27, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: d598c3c46ea6 Merge 5.16-rc4 into usb-next > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > console output: https://syzkaller.appspot.com/x/log.txt?x=14cf0e55b00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c6df5f09a0b9c823 > dashboard link: https://syzkaller.appspot.com/bug?extid=f39c1dad0b7db49ca4a8 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+f39c1dad0b7db49ca4a8@syzkaller.appspotmail.com > > INFO: task kworker/0:6:4133 blocked for more than 143 seconds. > Not tainted 5.16.0-rc4-syzkaller #0 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > task:kworker/0:6 state:D stack:21848 pid: 4133 ppid: 2 flags:0x00004000 > Workqueue: usb_hub_wq hub_event > Call Trace: > > context_switch kernel/sched/core.c:4972 [inline] > __schedule+0x931/0x2320 kernel/sched/core.c:6253 > schedule+0xd2/0x260 kernel/sched/core.c:6326 > schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6385 > __mutex_lock_common kernel/locking/mutex.c:680 [inline] > __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:740 > unregister_netdev+0xe/0x20 net/core/dev.c:11138 > r871xu_dev_remove+0x24f/0x2c0 drivers/staging/rtl8712/usb_intf.c:599 Seems like syz-executor ddosed the kernel. unregister_netdev() tries to lock rtnl and there are 8 mentions of rtnl_mutex in "Showing all locks held in the system" section. Looks false-positive to me With regards, Pavel Skripkin