From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) (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 0638B13A878 for ; Thu, 19 Sep 2024 20:29:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726777762; cv=none; b=Zzhv5bl9BGlR1z1trjFvpmJLewIt3KxoFIGfBU8N58I0jI7R8W/Sb/QG0IdcGF0LWTXCaQpVMCwvg/92McGPwaVoPwOd+b30JbHs2p+QFcNqzgWa46aqb6xO04gikC1Cb4j+6piot/7vzb9rkp0D2/RUVs77FnLFnU3PpwzmzdM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726777762; c=relaxed/simple; bh=DAJqHls5Z0Gh1+rOswdQCFx5R8rtot6DM8V0KKD9u4k=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=dcPDcIlGg/u1HXleLZuhylcq7uo/GyuX9IPMWroCQTesnTTjozTeyhzJPCw01Yb89B8DlNm2DCBWNzYzWkWiZfrchQfur7TKX8Dhc+P13ZHxh8gxC4bozSz+swLTvUq6c5QmwLcswnOUojZW1geLvl40MH1j7fAP/unKF2R2VQA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-il1-f198.google.com with SMTP id e9e14a558f8ab-3a08d4ada12so15327455ab.3 for ; Thu, 19 Sep 2024 13:29:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726777760; x=1727382560; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6DN2914apgWymUOCk6lZsIDS6FL9SL9oIBlj62IVcVU=; b=M7zXBim7mLPd0SZAVzeKvhBoGTmk9qnYrF9byold0GeiMpPhDcdbEjhet8tQWqrAC6 42UZoKA+HmNgU9z+A3di0vTpISzpy/h/F2Uv1KRzfBoWbdIOnbYmtbmlezV3r1vTP669 dRWaEfFYOTB+4K8IoFoPQv6q/m8bwnDyZGAB1g9htG9uN/Z25Yx2/dwyrSIgAUbDxuho RbeoInsflx8TDcrMwrVE8lX+CoSsX9X1D+3dyWrqnTX8m3frotg6HLvpY2g6SWPldhZK 1AgCLM4Uc8Ar6HJ080eFN8t0iy/DO/4VLE7D9faJC/ZxPBQxtqhpw4b6hvD3AYcwLqZO RG/g== X-Forwarded-Encrypted: i=1; AJvYcCXHVmCtU/2iqULUmZqx9idQo+wBrVZH0UgLC8qchjCEKA0NqCTJznQQC0oy21x3coYNdJjoPfZPsU4qnfs=@vger.kernel.org X-Gm-Message-State: AOJu0Yz0MFb5GB3OeYU3gRaW8oehGPivfIff864fUAZ6oGUoMGj9jLby 9poJzBE81zL3oAXQv/kwNF4tmpNZAbJ8kmcMBliH9FYAv8i6Ex0PSa1cz6UqlFCJLegn4X3Iz+5 FBj0Otkpus24T7029pFA8AQkKwwVv5fVzGEaHHboVjEtswOH/yook4T0= X-Google-Smtp-Source: AGHT+IHt8Wj47NWZOei2ttjIMadLl4DpZswtTAYAvyIz4+slOz8Scr0KIqmTQb5pCEQRNc5yaXG/eW3K7MTQipobsj3PtnrqluoZ Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:180d:b0:3a0:8c83:91fb with SMTP id e9e14a558f8ab-3a0c8d09198mr8524195ab.20.1726777760081; Thu, 19 Sep 2024 13:29:20 -0700 (PDT) Date: Thu, 19 Sep 2024 13:29:20 -0700 In-Reply-To: <000000000000aefb4d061e34a346@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <66ec89a0.050a0220.29194.0044.GAE@google.com> Subject: Re: [syzbot] [net?] INFO: task hung in linkwatch_event (4) From: syzbot To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 932d2d1fcb2b Merge tag 'dlm-6.12' of git://git.kernel.org/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=120d6607980000 kernel config: https://syzkaller.appspot.com/x/.config?x=c208b3605ba9ec44 dashboard link: https://syzkaller.appspot.com/bug?extid=2ba2d70f288cf61174e4 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1069b69f980000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-932d2d1f.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/fbcb7198214b/vmlinux-932d2d1f.xz kernel image: https://storage.googleapis.com/syzbot-assets/418eaebf4817/bzImage-932d2d1f.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2ba2d70f288cf61174e4@syzkaller.appspotmail.com INFO: task kworker/u4:3:5245 blocked for more than 143 seconds. Not tainted 6.11.0-syzkaller-05442-g932d2d1fcb2b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:23120 pid:5245 tgid:5245 ppid:2 flags:0x00004000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 linkwatch_event+0xe/0x60 net/core/link_watch.c:276 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 3 locks held by kworker/0:1/9: #0: ffff88801ac75948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac75948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900003b7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900003b7d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc4d08 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x99/0xfd0 net/wireless/reg.c:2480 2 locks held by kworker/u4:0/11: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900003d7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900003d7d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 1 lock held by khungtaskd/25: #0: ffffffff8e938b60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e938b60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e938b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6701 2 locks held by kworker/u4:10/2886: 2 locks held by dhcpcd/4810: #0: ffff88801ca91c40 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:700 [inline] #0: ffff88801ca91c40 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:6015 #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 1 lock held by dhcpcd/4811: #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 2 locks held by getty/4894: #0: ffff88801dfa10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000039b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz-execprog/5124: #0: ffff88803fe4bc40 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:700 [inline] #0: ffff88803fe4bc40 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:6015 #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 1 lock held by syz-executor/5122: #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 3 locks held by kworker/u4:1/5157: #0: ffff888035d58948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff888035d58948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90002ddfd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90002ddfd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc4d08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4736 3 locks held by kworker/u4:3/5245: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000246fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000246fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc4d08 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 2 locks held by kworker/u4:5/5250: #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac79148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc9000249fd00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000249fd00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 2 locks held by kworker/u4:7/5252: #0: ffff88801fe3e998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:560 #1: ffff88801fe28948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:989 2 locks held by syz-executor/5732: #0: ffff888035e21070 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:700 [inline] #0: ffff888035e21070 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:6015 #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 2 locks held by udevd/5760: #0: ffff8880119e8658 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:700 [inline] #0: ffff8880119e8658 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:6015 #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 8 locks held by syz-executor/5784: #0: ffff88801ed72420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2930 [inline] #0: ffff88801ed72420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff888046575888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff8880354e4968 (kn->active#59){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f561ca8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x1b4/0x890 drivers/net/netdevsim/bus.c:166 #4: ffff8880441160e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff8880441160e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1004 #5: ffff888044110250 (&devlink->lock_key#23){+.+.}-{3:3}, at: nsim_drv_probe+0xcb/0xb80 drivers/net/netdevsim/dev.c:1534 #6: ffffffff8fcc4d08 (rtnl_mutex){+.+.}-{3:3}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:678 [inline] #6: ffffffff8fcc4d08 (rtnl_mutex){+.+.}-{3:3}, at: nsim_create+0x408/0x890 drivers/net/netdevsim/netdev.c:750 #7: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #7: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #7: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 2 locks held by udevd/5785: #0: ffff8880122dd148 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:700 [inline] #0: ffff8880122dd148 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:6015 #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 2 locks held by udevd/5788: #0: ffff888011dcd8e0 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:700 [inline] #0: ffff888011dcd8e0 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:6015 #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 1 lock held by modprobe/5813: #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #0: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 2 locks held by modprobe/5814: #0: ffff88804c225df0 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:700 [inline] #0: ffff88804c225df0 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x2f9/0x6e0 mm/memory.c:6015 #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:3898 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:3923 [inline] #1: ffffffff8ea300e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0xcfb/0x2390 mm/page_alloc.c:4329 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 25 Comm: khungtaskd Not tainted 6.11.0-syzkaller-05442-g932d2d1fcb2b #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.