From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f207.google.com (mail-il1-f207.google.com [209.85.166.207]) (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 82CFA30C364 for ; Mon, 24 Nov 2025 13:57:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763992654; cv=none; b=Byl3F0wxpX9L0dHvUjyWi2Pklj+g72Uz+Z6o6VHHwByVTL3XKAIt2beFEMgUQzOTHvt3mdi9xcENe7LoHm8ekJABo067xMjpyvU+0p7wWR16Ub+F3UDl9Y8gK9Mm3yLWPrdJ0e0fT/ArhbmA5eyAr+WDkjl5A7n3Ux//VAfYHZU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763992654; c=relaxed/simple; bh=7u1rcJSzAVPEO6iJQOpHGAGzZqukkBE3lT1r4EtHZRk=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=QA30t6ZiCEgV+E1iB8z9xzKsr9sfo5MBWcBJFefJjgD3D23NMZIXI1p4v05Tp/MeArMPvl9IItkaMABo/C48n0e2Z0ASRzF+2YmEs26gaDOYcgZF14OoSnexI11kP9VF6V3StUMwlcXjrrPEro+LBsQxTfwyelHXHf2iPPtle/Q= 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=209.85.166.207 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-f207.google.com with SMTP id e9e14a558f8ab-433689014feso47694415ab.1 for ; Mon, 24 Nov 2025 05:57:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763992651; x=1764597451; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=KDg6EKj7SaQSDp3ekiM2QxLRUQ7A/jBw0qAYjumEdjs=; b=u3ff2EFYQXFwgt5M9qDnCxmuYDHJTNJMw2fb2iEX5TjfHxtBtJcEzRjBYx5pYn+FW2 RSR2mnrIqPHXlKYhr6yROORHhfB8LXB46OiKUy22awpX2yhHB1w66Dh+rcycX4AGeFWc eOONJI9UzE6ZhgFASh0U4FAjHDr7882g1QLrFbvfqHkTfrx7MO//oaNglccrjnx/Wojr jYNnD5ZksEcIuOBz8AWwnABi+KB9NdiuRCcUGPGlRsV84JynjzMsQ1psT3Hg/WiYwxN8 06YH1YdTLwSloX5Rg4VlZOdUX93/nD2m9ag0+HTpHleaZABAP1/HATXxg/sV13Sogkbq LDlQ== X-Forwarded-Encrypted: i=1; AJvYcCUvIiAURnSKDVE1B431Jvplwj8nraBwyVbZGAw2TEQfKKadwEygh1eoAlM2C/b/edho5zzNoO+oOiFb+oo=@vger.kernel.org X-Gm-Message-State: AOJu0YwZJMndn9FbO7GJEMhQkv8uBLXVW2yBtwERUC80DgbTbwt6aaaE fO8rBpc5PmXe6xwQ1SposTM64TYcaI2H7PMGOq9zBSaMOcEPqSMc0pkqNttGO1+e7A1vzgRGSaw sBQ+sY2oe832aeSJK+E7ORC1MLLhPepR5jtscchSvktIAOa0E42vPldJIbw0= X-Google-Smtp-Source: AGHT+IGHegIS/FJ6IOSE5Z8unu6OeaAFouYrkM4NI8HufSewwwxpt33mdqPJ+ry16+Ya9W8rNlLaXqNQL/+wn/G0cvPJ8Xepg0It Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1b08:b0:433:3315:e9ee with SMTP id e9e14a558f8ab-435b985af0emr86836845ab.10.1763992651452; Mon, 24 Nov 2025 05:57:31 -0800 (PST) Date: Mon, 24 Nov 2025 05:57:31 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6924644b.a70a0220.d98e3.008d.GAE@google.com> Subject: [syzbot] [kernel?] possible deadlock in device_create (2) From: syzbot To: dakr@kernel.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, rafael@kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 88cbd8ac379c Add linux-next specific files for 20251120 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=12cbba12580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a8c4b5c6816f227d dashboard link: https://syzkaller.appspot.com/bug?extid=e93eea510a0fc08f6805 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/caaf2a62c9c1/disk-88cbd8ac.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4172ec8ca062/vmlinux-88cbd8ac.xz kernel image: https://storage.googleapis.com/syzbot-assets/bee849e7df9a/bzImage-88cbd8ac.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e93eea510a0fc08f6805@syzkaller.appspotmail.com cdc_mbim 1-1:1.0: setting tx_max = 184 cdc_mbim 1-1:1.0: cdc-wdm0: USB WDM device ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/1:6/5950 is trying to acquire lock: ffffffff8e448520 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline] ffffffff8e448520 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4899 [inline] ffffffff8e448520 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:5234 [inline] ffffffff8e448520 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_cache_noprof+0x40/0x700 mm/slub.c:5766 but task is already holding lock: ffffffff8ecda808 (gdp_mutex){+.+.}-{4:4}, at: get_device_parent+0x16f/0x3a0 drivers/base/core.c:3322 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (gdp_mutex){+.+.}-{4:4}: lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:770 get_device_parent+0x16f/0x3a0 drivers/base/core.c:3322 device_add+0x2e1/0xb80 drivers/base/core.c:3669 device_create_groups_vargs drivers/base/core.c:4427 [inline] device_create+0x25b/0x2f0 drivers/base/core.c:4466 msr_device_create+0x33/0x50 arch/x86/kernel/msr.c:251 cpuhp_invoke_callback+0x445/0x860 kernel/cpu.c:195 cpuhp_thread_fun+0x3f4/0x850 kernel/cpu.c:1105 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 -> #6 (cpuhp_state-up){+.+.}-{0:0}: lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 cpuhp_lock_acquire kernel/cpu.c:104 [inline] cpuhp_thread_fun+0x182/0x850 kernel/cpu.c:1082 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 -> #5 (cpu_hotplug_lock){++++}-{0:0}: lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] cpus_read_lock+0x42/0x160 kernel/cpu.c:491 static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190 nbd_reconnect_socket drivers/block/nbd.c:1342 [inline] nbd_genl_reconfigure+0x10d8/0x1a50 drivers/block/nbd.c:2431 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:746 ____sys_sendmsg+0x505/0x870 net/socket.c:2634 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2688 __sys_sendmsg net/socket.c:2720 [inline] __do_sys_sendmsg net/socket.c:2725 [inline] __se_sys_sendmsg net/socket.c:2723 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2723 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&nsock->tx_lock){+.+.}-{4:4}: lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:770 nbd_handle_cmd drivers/block/nbd.c:1143 [inline] nbd_queue_rq+0x257/0xf10 drivers/block/nbd.c:1207 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2137 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xdac/0x1570 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2375 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2986 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225 blk_finish_plug block/blk-core.c:1252 [inline] __submit_bio+0x2d3/0x5a0 block/blk-core.c:651 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2eb/0xa50 block/blk-core.c:755 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2447 filemap_read_folio+0x117/0x380 mm/filemap.c:2496 do_read_cache_folio+0x358/0x590 mm/filemap.c:4095 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:765 bdev_open+0x31e/0xd30 block/bdev.c:974 blkdev_open+0x457/0x600 block/fops.c:703 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4597 [inline] path_openat+0x33ce/0x3d90 fs/namei.c:4756 do_filp_open+0x1fa/0x410 fs/namei.c:4783 do_sys_openat2+0x121/0x1c0 fs/open.c:1432 do_sys_open fs/open.c:1447 [inline] __do_sys_openat fs/open.c:1463 [inline] __se_sys_openat fs/open.c:1458 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1458 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&cmd->lock){+.+.}-{4:4}: lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:770 nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1199 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2137 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xdac/0x1570 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2375 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2986 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225 blk_finish_plug block/blk-core.c:1252 [inline] __submit_bio+0x2d3/0x5a0 block/blk-core.c:651 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2eb/0xa50 block/blk-core.c:755 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2447 filemap_read_folio+0x117/0x380 mm/filemap.c:2496 do_read_cache_folio+0x358/0x590 mm/filemap.c:4095 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:765 bdev_open+0x31e/0xd30 block/bdev.c:974 blkdev_open+0x457/0x600 block/fops.c:703 do_dentry_open+0x7ce/0x1420 fs/open.c:962 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4597 [inline] path_openat+0x33ce/0x3d90 fs/namei.c:4756 do_filp_open+0x1fa/0x410 fs/namei.c:4783 do_sys_openat2+0x121/0x1c0 fs/open.c:1432 do_sys_open fs/open.c:1447 [inline] __do_sys_openat fs/open.c:1463 [inline] __se_sys_openat fs/open.c:1458 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1458 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (set->srcu){.+.?}-{0:0}: lock_sync+0xba/0x160 kernel/locking/lockdep.c:5916 srcu_lock_sync include/linux/srcu.h:197 [inline] __synchronize_srcu+0x96/0x3a0 kernel/rcu/srcutree.c:1503 blk_throtl_init+0x298/0x410 block/blk-throttle.c:1324 tg_set_conf+0x1c6/0x4b0 block/blk-throttle.c:1359 cgroup_file_write+0x3a1/0x740 kernel/cgroup/cgroup.c:4312 kernfs_fop_write_iter+0x3af/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->q_usage_counter(io)#17){++++}-{0:0}: lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 blk_alloc_queue+0x538/0x620 block/blk-core.c:461 blk_mq_alloc_queue block/blk-mq.c:4410 [inline] __blk_mq_alloc_disk+0x15c/0x340 block/blk-mq.c:4457 loop_add+0x411/0xad0 drivers/block/loop.c:2202 loop_init+0xd9/0x170 drivers/block/loop.c:2437 do_one_initcall+0x1fb/0x870 init/main.c:1378 do_initcall_level+0x104/0x190 init/main.c:1440 do_initcalls+0x59/0xa0 init/main.c:1456 kernel_init_freeable+0x334/0x4b0 init/main.c:1688 kernel_init+0x1d/0x1d0 init/main.c:1578 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2130 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4301 [inline] fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4315 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4899 [inline] slab_alloc_node mm/slub.c:5234 [inline] __kmalloc_cache_noprof+0x40/0x700 mm/slub.c:5766 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] class_dir_create_and_add drivers/base/core.c:3279 [inline] get_device_parent+0x255/0x3a0 drivers/base/core.c:3339 device_add+0x2e1/0xb80 drivers/base/core.c:3669 wwan_create_dev+0x15a/0x1f0 drivers/net/wwan/wwan_core.c:249 wwan_create_port+0xe0/0xa20 drivers/net/wwan/wwan_core.c:462 wdm_wwan_init+0x80/0x180 drivers/usb/class/cdc-wdm.c:938 wdm_create+0x12be/0x1720 drivers/usb/class/cdc-wdm.c:1125 usb_cdc_wdm_register+0x33/0x60 drivers/usb/class/cdc-wdm.c:1205 cdc_mbim_bind+0x3e1/0x640 drivers/net/usb/cdc_mbim.c:169 usbnet_probe+0xab5/0x28f0 drivers/net/usb/usbnet.c:1802 usb_probe_interface+0x668/0xc90 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0xad0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:575 device_add+0x7b6/0xb80 drivers/base/core.c:3745 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x3c0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0xad0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:575 device_add+0x7b6/0xb80 drivers/base/core.c:3745 usb_new_device+0xa39/0x1720 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x29b1/0x4ef0 drivers/usb/core/hub.c:5953 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 other info that might help us debug this: Chain exists of: fs_reclaim --> cpuhp_state-up --> gdp_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(gdp_mutex); lock(cpuhp_state-up); lock(gdp_mutex); lock(fs_reclaim); *** DEADLOCK *** 7 locks held by kworker/1:6/5950: #0: ffff8880202a3d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x841/0x15e0 kernel/workqueue.c:3236 #1: ffffc900046bfb80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x868/0x15e0 kernel/workqueue.c:3237 #2: ffff88802896d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff88802896d198 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4ef0 drivers/usb/core/hub.c:5899 #3: ffff88807f14d198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff88807f14d198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #4: ffff88806b989160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff88806b989160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #5: ffffffff8ef587e8 (wwan_register_lock){+.+.}-{4:4}, at: wwan_create_dev+0x1c/0x1f0 drivers/net/wwan/wwan_core.c:223 #6: ffffffff8ecda808 (gdp_mutex){+.+.}-{4:4}, at: get_device_parent+0x16f/0x3a0 drivers/base/core.c:3322 stack backtrace: CPU: 1 UID: 0 PID: 5950 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2130 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4301 [inline] fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4315 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4899 [inline] slab_alloc_node mm/slub.c:5234 [inline] __kmalloc_cache_noprof+0x40/0x700 mm/slub.c:5766 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] class_dir_create_and_add drivers/base/core.c:3279 [inline] get_device_parent+0x255/0x3a0 drivers/base/core.c:3339 device_add+0x2e1/0xb80 drivers/base/core.c:3669 wwan_create_dev+0x15a/0x1f0 drivers/net/wwan/wwan_core.c:249 wwan_create_port+0xe0/0xa20 drivers/net/wwan/wwan_core.c:462 wdm_wwan_init+0x80/0x180 drivers/usb/class/cdc-wdm.c:938 wdm_create+0x12be/0x1720 drivers/usb/class/cdc-wdm.c:1125 usb_cdc_wdm_register+0x33/0x60 drivers/usb/class/cdc-wdm.c:1205 cdc_mbim_bind+0x3e1/0x640 drivers/net/usb/cdc_mbim.c:169 usbnet_probe+0xab5/0x28f0 drivers/net/usb/usbnet.c:1802 usb_probe_interface+0x668/0xc90 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0xad0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:575 device_add+0x7b6/0xb80 drivers/base/core.c:3745 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c4/0x3c0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0xad0 drivers/base/dd.c:659 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:801 driver_probe_device+0x4f/0x240 drivers/base/dd.c:831 __device_attach_driver+0x279/0x430 drivers/base/dd.c:959 bus_for_each_drv+0x251/0x2e0 drivers/base/bus.c:500 __device_attach+0x2b8/0x430 drivers/base/dd.c:1031 bus_probe_device+0x185/0x260 drivers/base/bus.c:575 device_add+0x7b6/0xb80 drivers/base/core.c:3745 usb_new_device+0xa39/0x1720 drivers/usb/core/hub.c:2695 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x29b1/0x4ef0 drivers/usb/core/hub.c:5953 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 wwan wwan0: port wwan0mbim0 attached cdc_mbim 1-1:1.0 wwan0: register 'cdc_mbim' at usb-dummy_hcd.0-1, CDC MBIM, b6:b8:b8:38:29:fc usb 1-1: USB disconnect, device number 89 cdc_mbim 1-1:1.0 wwan0: unregister 'cdc_mbim' usb-dummy_hcd.0-1, CDC MBIM wwan wwan0: port wwan0mbim0 disconnected usb 1-1: new full-speed USB device number 90 using dummy_hcd usb 1-1: New USB device found, idVendor=0ccd, idProduct=00b3, bcdDevice=2d.ea usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 1-1: Product: syz usb 1-1: Manufacturer: syz usb 1-1: SerialNumber: syz usb 1-1: config 0 descriptor?? usb 1-1: dvb_usb_v2: found a 'TerraTec NOXON DAB Stick' in warm state dvb_usb_rtl28xxu 1-1:0.0: probe with driver dvb_usb_rtl28xxu failed with error -71 usb 1-1: USB disconnect, device number 90 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup