INFO: task udevd:10568 blocked for more than 143 seconds. Not tainted 6.6.94-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25712 pid:10568 ppid:5140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14e2/0x4580 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+0x6eb/0xf70 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7e0 mm/filemap.c:3771 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x350 block/partitions/core.c:718 adfspart_check_POWERTEC+0x8d/0xf00 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+0x73a/0x1410 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:655 blkdev_get_by_dev+0x279/0x600 block/bdev.c:797 blkdev_open+0x152/0x360 block/fops.c:589 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3632 [inline] path_openat+0x274b/0x3190 fs/namei.c:3789 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419 do_sys_open fs/open.c:1434 [inline] __do_sys_openat fs/open.c:1450 [inline] __se_sys_openat fs/open.c:1445 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1445 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0c028a7407 RSP: 002b:00007ffce1d721f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0c02f73880 RCX: 00007f0c028a7407 RDX: 00000000000a0800 RSI: 0000557494554440 RDI: ffffffffffffff9c RBP: 0000557494553910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000557494567b50 R13: 000055749456daf0 R14: 0000000000000000 R15: 0000557494567b50 Showing all locks held in the system: 1 lock held by khungtaskd/28: #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 1 lock held by klogd/5129: #0: ffff8880b8e3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 2 locks held by getty/5527: #0: ffff888031c680a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/u4:12/6317: #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc9000c06fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000c06fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 2 locks held by kworker/u4:0/30323: 1 lock held by udevd/10568: #0: ffff8880218e34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788 2 locks held by syz.6.13385/14900: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 #1: ffffffff8cd35738 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8cd35738 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 2 locks held by syz.7.13391/14919: #0: ffffffff8e013a50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1074 #1: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:16515 2 locks held by syz.1.13403/14945: #0: ffffffff8e013a50 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1074 #1: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:16515 1 lock held by syz.0.13404/14947: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 1 lock held by syz.0.13404/14948: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 1 lock held by syz.0.13404/14949: #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfaecc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6472 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 30323 Comm: kworker/u4:0 Not tainted 6.6.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: 0x0 (bond5) RIP: 0010:check_preemption_disabled+0x47/0x110 lib/smp_processor_id.c:55 Code: 9d 75 65 8b 0d 62 6d 9d 75 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b <41> 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 RSP: 0018:ffffc900036a7960 EFLAGS: 00000082 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 7ad8bc2ca1015400 RDX: 0000000000000000 RSI: ffffffff8afc68e0 RDI: ffffffff8afc68a0 RBP: ffffc900036a7aa8 R08: ffffffff8e49ab2f R09: 1ffffffff1c93565 R10: dffffc0000000000 R11: fffffbfff1c93566 R12: 1ffff920006d4f40 R13: ffffffff97079a98 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563072e0b000 CR3: 000000000cb30000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 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_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xcb/0x410 kernel/locking/lockdep.c:5725 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 debug_object_deactivate+0x67/0x350 lib/debugobjects.c:764 debug_work_deactivate kernel/workqueue.c:577 [inline] process_one_work kernel/workqueue.c:2562 [inline] process_scheduled_works+0x324/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 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