INFO: task syz.3.818:9279 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.818 state:D stack:28504 pid:9279 tgid:9276 ppid:5847 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:901 blk_trace_ioctl+0x315/0x740 kernel/trace/blktrace.c:947 blkdev_common_ioctl+0x13a7/0x3250 block/ioctl.c:712 blkdev_ioctl+0x528/0x740 block/ioctl.c:786 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f255b19bf79 RSP: 002b:00007f25593d5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f255b416180 RCX: 00007f255b19bf79 RDX: 0000000000000000 RSI: 0000000000001274 RDI: 000000000000000b RBP: 00007f255b2327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f255b416218 R14: 00007f255b416180 R15: 00007f255b53fa48 INFO: task syz.3.818:9280 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.818 state:D stack:28728 pid:9280 tgid:9276 ppid:5847 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 blk_trace_remove kernel/trace/blktrace.c:562 [inline] blk_trace_ioctl+0x39b/0x740 kernel/trace/blktrace.c:950 blkdev_common_ioctl+0x13a7/0x3250 block/ioctl.c:712 blkdev_ioctl+0x528/0x740 block/ioctl.c:786 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f255b19bf79 RSP: 002b:00007f2558fb2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f255b416270 RCX: 00007f255b19bf79 RDX: 0000000000000000 RSI: 0000000000001276 RDI: 000000000000000b RBP: 00007f255b2327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f255b416308 R14: 00007f255b416270 R15: 00007f255b53fa48 Showing all locks held in the system: 2 locks held by init/1: 6 locks held by kworker/1:0/24: #0: ffff888021aed948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888021aed948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc900001e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900001e7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff888029f90198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888029f90198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff888077110198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888077110198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008 #4: ffff888059df9160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff888059df9160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008 #5: ffffffff8e5fd770 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214 1 lock held by khungtaskd/31: #0: ffffffff8e7603e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7603e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7603e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u9:0/51: #0: ffff888028bcb948 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888028bcb948 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90000bb7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000bb7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff88814e434ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 #3: ffff88814e4340c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190 net/bluetooth/hci_sync.c:5734 3 locks held by udevd/5190: 2 locks held by dhcpcd/5484: 3 locks held by crond/5562: #0: ffff888023580580 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] #0: ffff888023580580 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_fault+0x97c/0x1320 mm/filemap.c:3556 #1: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655 #2: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 2 locks held by getty/5580: #0: ffff8880372c80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by sshd-session/5806: 2 locks held by syz-executor/5807: 3 locks held by syz-executor/5832: 6 locks held by kworker/1:8/5922: 4 locks held by udevd/5942: #0: ffff888053102b08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff888079394488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff88804731a878 (kn->active#29){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88804731a878 (kn->active#29){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff888077110198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff888077110198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 2 locks held by udevd/5957: 2 locks held by syz-executor/6157: 3 locks held by kworker/u8:10/7006: 4 locks held by udevd/8400: #0: ffff88802b207d58 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff888032165888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888153896698 (kn->active#29){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888153896698 (kn->active#29){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff888054965198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff888054965198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 3 locks held by syz.3.818/9277: #0: ffff888026294210 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0x298/0x430 kernel/trace/blktrace.c:788 #1: ffffffff8e7be048 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3b8/0x920 kernel/relay.c:517 #2: ffffffff8e8845c0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4420 [inline] #2: ffffffff8e8845c0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim+0xbd/0x310 mm/page_alloc.c:4445 1 lock held by syz.3.818/9279: #0: ffff888026294210 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0x8f/0x610 kernel/trace/blktrace.c:901 1 lock held by syz.3.818/9280: #0: ffff888026294210 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_remove kernel/trace/blktrace.c:562 [inline] #0: ffff888026294210 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_ioctl+0x39b/0x740 kernel/trace/blktrace.c:950 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5922 Comm: kworker/1:8 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: usb_hub_wq hub_event RIP: 0010:__sanitizer_cov_trace_pc+0x45/0x70 kernel/kcov.c:222 Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 54 16 00 00 00 74 2c 8b 91 30 16 00 00 83 fa 02 75 21 48 8b 91 38 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 34 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 RSP: 0000:ffffc900045d5a40 EFLAGS: 00000246 RAX: ffffffff8ba1f0e2 RBX: 0000000000000021 RCX: ffff888027775ac0 RDX: ffffc90014c17000 RSI: 00000000000fffff RDI: ffffffff8e84f1e0 RBP: ffffc900045d5be8 R08: ffffffff820a4e4f R09: ffffffff8e7603e0 R10: ffffc900045d5b28 R11: fffff520008bab67 R12: 1ffff920008bab5c R13: ffff8880796c3a00 R14: ffffffff8e84f1e0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88812556f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd32b7419a0 CR3: 000000007e13c000 CR4: 00000000003526f0 Call Trace: idr_find+0x12/0x60 lib/idr.c:175 shrink_slab_memcg mm/shrinker.c:537 [inline] shrink_slab+0x594/0x1150 mm/shrinker.c:628 shrink_one+0x2d9/0x710 mm/vmscan.c:4918 shrink_many mm/vmscan.c:4979 [inline] lru_gen_shrink_node mm/vmscan.c:5057 [inline] shrink_node+0x30e2/0x39d0 mm/vmscan.c:6037 shrink_zones mm/vmscan.c:6290 [inline] do_try_to_free_pages+0x6a2/0x1980 mm/vmscan.c:6352 try_to_free_pages+0x8f2/0xe90 mm/vmscan.c:6591 __perform_reclaim mm/page_alloc.c:4423 [inline] __alloc_pages_direct_reclaim+0x148/0x310 mm/page_alloc.c:4445 __alloc_pages_slowpath+0x57d/0xd40 mm/page_alloc.c:4845 __alloc_frozen_pages_noprof+0x322/0x380 mm/page_alloc.c:5262 alloc_slab_page mm/slub.c:3238 [inline] allocate_slab+0x11f/0x660 mm/slub.c:3419 new_slab mm/slub.c:3469 [inline] refill_objects+0x331/0x3c0 mm/slub.c:7091 refill_sheaf mm/slub.c:2787 [inline] __pcs_replace_empty_main+0x2b9/0x620 mm/slub.c:4536 alloc_from_pcs mm/slub.c:4639 [inline] slab_alloc_node mm/slub.c:4773 [inline] __kmalloc_cache_noprof+0x392/0x660 mm/slub.c:5292 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1204 [inline] kobject_uevent_env+0x28c/0x9e0 lib/kobject_uevent.c:540 device_del+0x750/0x8f0 drivers/base/core.c:3896 fw_load_sysfs_fallback drivers/base/firmware_loader/fallback.c:124 [inline] fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:162 [inline] firmware_fallback_sysfs+0x38d/0xa30 drivers/base/firmware_loader/fallback.c:238 _request_firmware+0x1052/0x1780 drivers/base/firmware_loader/main.c:898 request_firmware+0x36/0x50 drivers/base/firmware_loader/main.c:948 dvb_usbv2_download_firmware+0x15c/0x340 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:34 dvb_usbv2_probe+0x291b/0x3d40 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:956 usb_probe_interface+0x668/0xc90 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:661 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:803 driver_probe_device+0x4f/0x240 drivers/base/dd.c:833 __device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c5/0x450 drivers/base/dd.c:1033 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574 device_add+0x7b6/0xb70 drivers/base/core.c:3689 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+0x1c4/0x3b0 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:661 __driver_probe_device+0x18c/0x320 drivers/base/dd.c:803 driver_probe_device+0x4f/0x240 drivers/base/dd.c:833 __device_attach_driver+0x2d4/0x4c0 drivers/base/dd.c:961 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c5/0x450 drivers/base/dd.c:1033 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1088 bus_probe_device+0x12a/0x220 drivers/base/bus.c:574 device_add+0x7b6/0xb70 drivers/base/core.c:3689 usb_new_device+0xa08/0x16f0 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+0x2a1c/0x4f30 drivers/usb/core/hub.c:5953 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245