INFO: task udevd:21935 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:25752 pid:21935 ppid:5139 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6701 schedule+0xbd/0x170 kernel/sched/core.c:6775 io_schedule+0x80/0xd0 kernel/sched/core.c:9024 folio_wait_bit_common+0x881/0xfa0 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7f0 mm/filemap.c:3791 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x350 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+0x755/0x1450 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:668 blkdev_get_by_dev+0x3a9/0x610 block/bdev.c:810 blkdev_open+0x14e/0x360 block/fops.c:589 do_dentry_open+0x880/0x14b0 fs/open.c:929 do_open fs/namei.c:3640 [inline] path_openat+0x284f/0x3270 fs/namei.c:3801 do_filp_open+0x1f2/0x430 fs/namei.c:3828 do_sys_openat2+0x134/0x1d0 fs/open.c:1422 do_sys_open fs/open.c:1437 [inline] __do_sys_openat fs/open.c:1453 [inline] __se_sys_openat fs/open.c:1448 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1448 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff94d8a7407 RSP: 002b:00007ffd24c176c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ff94e082880 RCX: 00007ff94d8a7407 RDX: 00000000000a0800 RSI: 0000565461c47150 RDI: ffffffffffffff9c RBP: 0000565461c35910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000565461c5c080 R13: 0000565461c4d410 R14: 0000000000000000 R15: 0000565461c5c080 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:6/1082: 2 locks held by getty/5533: #0: ffff88802cbc80a0 (&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+0x428/0x1370 drivers/tty/n_tty.c:2217 1 lock held by udevd/21935: #0: ffff888021f034c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801 3 locks held by kworker/u4:4/26611: #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c71538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc9000b64fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000b64fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #2: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 2 locks held by kworker/0:3/28563: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 #1: ffffc90012f77d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90012f77d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2730 2 locks held by syz.3.6871/29429: #0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8e3d6b08 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3514 #1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 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+0xf59/0xfa0 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8438 Comm: kworker/u4:13 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: bond0 bond_alb_monitor RIP: 0010:mark_lock+0x22/0x320 kernel/locking/lockdep.c:4647 Code: 00 00 00 0f 1f 44 00 00 55 41 57 41 56 41 55 41 54 53 50 89 d5 49 89 f6 48 89 fb 49 bd 00 00 00 00 00 fc ff df 83 fa 08 75 29 <4d> 8d 7e 20 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 74 02 RSP: 0018:ffffc9001050f360 EFLAGS: 00000046 RAX: 00000000000c8000 RBX: ffff88807c8c3c00 RCX: ffffffff8168907b RDX: 0000000000000008 RSI: ffff88807c8c4730 RDI: ffff88807c8c3c00 RBP: 0000000000000008 R08: dffffc0000000000 R09: 1ffffffff223d6a0 R10: dffffc0000000000 R11: fffffbfff223d6a1 R12: 0000000000048000 R13: dffffc0000000000 R14: ffff88807c8c4730 R15: ffff88807c8c4750 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f32071ed2f8 CR3: 0000000075962000 CR4: 00000000003506f0 Call Trace: mark_usage kernel/locking/lockdep.c:4599 [inline] __lock_acquire+0xd3e/0x7d80 kernel/locking/lockdep.c:5091 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 debug_objects_fill_pool+0xab/0x790 lib/debugobjects.c:653 debug_object_assert_init+0x66/0x300 lib/debugobjects.c:940 debug_timer_assert_init kernel/time/timer.c:792 [inline] debug_assert_init kernel/time/timer.c:837 [inline] __mod_timer+0x55/0xd60 kernel/time/timer.c:1020 queue_delayed_work_on+0x131/0x200 kernel/workqueue.c:2006 queue_delayed_work include/linux/workqueue.h:577 [inline] bond_alb_monitor+0x1229/0x17c0 drivers/net/bonding/bond_alb.c:1629 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 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