INFO: task udevd:26102 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25680 pid:26102 ppid:5142 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 io_schedule+0x80/0xd0 kernel/sched/core.c:9023 folio_wait_bit_common+0x714/0xfa0 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7d0 mm/filemap.c:3786 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x340 block/partitions/core.c:718 adfspart_check_POWERTEC+0x93/0xed0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:600 [inline] bdev_disk_changed+0x740/0x1420 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:672 blkdev_get_by_dev+0x279/0x600 block/bdev.c:814 blkdev_open+0x152/0x360 block/fops.c:589 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3640 [inline] path_openat+0x27f1/0x3230 fs/namei.c:3797 do_filp_open+0x1f5/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fabc34a7407 RSP: 002b:00007ffce51c4410 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fabc3b55880 RCX: 00007fabc34a7407 RDX: 00000000000a0800 RSI: 00005591d5ff0a30 RDI: ffffffffffffff9c RBP: 00005591d5fd7910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005591d5fefe00 R13: 00005591d5fef410 R14: 0000000000000000 R15: 00005591d5fefe00 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by pvrusb2-context/2321: #0: ffff88805d5a4188 (&hdw->big_lock_mutex){+.+.}-{3:3}, at: pvr2_hdw_initialize+0xe5/0x3c30 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2326 #1: ffffffff8cfdc690 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xfd/0x2b0 kernel/umh.c:215 3 locks held by udevd/5142: 2 locks held by getty/5533: #0: ffff88814c5760a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 6 locks held by kworker/1:7/10888: #0: ffff888147e7b938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888147e7b938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc900038ffd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc900038ffd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffff8880254b9190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline] #2: ffff8880254b9190 (&dev->mutex){....}-{3:3}, at: hub_event+0x180/0x49f0 drivers/usb/core/hub.c:5861 #3: ffff888047b32190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline] #3: ffff888047b32190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x10b/0x8a0 drivers/usb/core/hub.c:2306 #4: ffff888047b37160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:995 [inline] #4: ffff888047b37160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff888047b37160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb6/0x7a0 drivers/base/dd.c:1292 #5: ffff88805d5a4188 (&hdw->big_lock_mutex){+.+.}-{3:3}, at: pvr2_hdw_disconnect+0x6d/0x500 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2710 3 locks held by kworker/1:0/21664: 2 locks held by kworker/u4:0/24102: #0: ffff888018f63138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888018f63138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc9000c907d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000c907d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 1 lock held by udevd/26102: #0: ffff888021e224c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 4 locks held by udevd/26130: #0: ffff888063f6a8b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb1/0xd50 fs/seq_file.c:182 #1: ffff88805bd6f488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x5c/0x410 fs/kernfs/file.c:172 #2: ffff888060dfe8c0 (kn->active#18){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888060dfe8c0 (kn->active#18){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x410 fs/kernfs/file.c:173 #3: ffff888047b32190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:1000 [inline] #3: ffff888047b32190 (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 21664 Comm: kworker/1:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_power_efficient gc_worker RIP: 0010:check_preemption_disabled+0x3/0x110 lib/smp_processor_id.c:13 Code: ff ff ff cc cc cc cc f3 0f 1e fa 48 c7 c7 40 89 1c 8b 48 c7 c6 80 89 1c 8b eb 0c 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 41 57 <41> 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 RSP: 0018:ffffc900044af948 EFLAGS: 00000083 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff818d9178 RDX: 0000000000000000 RSI: ffffffff8b1c8980 RDI: ffffffff8b1c8940 RBP: ffffc900044afa50 R08: ffffffff8e8b02af R09: 1ffffffff1d16055 R10: dffffc0000000000 R11: fffffbfff1d16056 R12: 0000000000000200 R13: dffffc0000000000 R14: 1ffff92000895f34 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9e5cbe92f8 CR3: 000000002f263000 CR4: 00000000003506e0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:700 trace_irq_enable+0x37/0xe0 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:56 seqcount_lockdep_reader_access+0x12b/0x1d0 include/linux/seqlock.h:-1 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:350 [inline] gc_worker+0x317/0x1490 net/netfilter/nf_conntrack_core.c:1504 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 vkms_vblank_simulate: vblank timer overrun