INFO: task udevd:6217 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23528 pid:6217 ppid:5137 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 __filemap_get_folio+0xbc/0xbb0 mm/filemap.c:1910 truncate_inode_pages_range+0x46b/0xfb0 mm/truncate.c:401 kill_bdev block/bdev.c:76 [inline] blkdev_flush_mapping+0x132/0x290 block/bdev.c:649 blkdev_put_whole block/bdev.c:680 [inline] blkdev_put+0x498/0x760 block/bdev.c:958 blkdev_release+0x84/0x90 block/fops.c:604 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x95a/0x2460 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f082c2a7407 RSP: 002b:00007fff666f8a80 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: 0000000000000008 RBX: 00007f082c945880 RCX: 00007f082c2a7407 RDX: 00000000000a0800 RSI: 000055eb2b5c7800 RDI: ffffffffffffff9c RBP: 000055eb2b5af910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055eb2b5c3ba0 R13: 000055eb2b5c7410 R14: 0000000000000000 R15: 000055eb2b5c3ba0 Showing all locks held in the system: 1 lock held by ksoftirqd/0/16: #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567 1 lock held by khungtaskd/29: #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5532: #0: ffff8880323990a0 (&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 1 lock held by udevd/6217: #0: ffff888021fed4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xff/0x760 block/bdev.c:944 2 locks held by kworker/u4:25/13477: 2 locks held by kworker/1:0/13865: #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+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90003737d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90003737d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 2 locks held by kworker/u4:30/14808: 2 locks held by syz.1.2828/16030: 2 locks held by dhcpcd/16031: #0: ffff88804e1b0e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #0: ffff88804e1b0e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff88804e1b0e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1420 #1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 2 locks held by syz.3.2830/16033: ============================================= 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 03/18/2026 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: 13477 Comm: kworker/u4:25 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline] RIP: 0010:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:699 Code: 84 1d ff ff ff eb 8a e8 1e 65 15 09 48 c7 c7 40 89 13 8d 4c 89 f6 e8 bf 68 ec 02 e9 44 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1e fa 41 57 41 56 53 65 ff 05 d8 d0 92 7e e8 db 7a 15 09 89 RSP: 0018:ffffc90004aeefd8 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8168ad76 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e8b15e8 RBP: ffffc90004aef0f0 R08: ffffffff8e8b15ef R09: 1ffffffff1d162bd R10: dffffc0000000000 R11: fffffbfff1d162be R12: ffffffff81710aa1 R13: dffffc0000000000 R14: ffffffff974b9c78 R15: 1ffff9200095de08 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fae12be92f8 CR3: 000000002555a000 CR4: 00000000003506e0 DR0: fffffffffffffffd DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff13 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0xb5/0x8c0 kernel/locking/lockdep.c:5765 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x71/0x120 kernel/locking/spinlock.c:194 debug_rcu_head_queue kernel/rcu/rcu.h:228 [inline] kvfree_call_rcu+0xb1/0x790 kernel/rcu/tree.c:3443 cfg80211_update_known_bss+0x175/0x930 net/wireless/scan.c:-1 __cfg80211_bss_update+0x144/0x21f0 net/wireless/scan.c:1872 cfg80211_inform_single_bss_frame_data net/wireless/scan.c:2982 [inline] cfg80211_inform_bss_frame_data+0xb42/0x13d0 net/wireless/scan.c:3013 ieee80211_bss_info_update+0x759/0x9b0 net/mac80211/scan.c:211 ieee80211_rx_bss_info net/mac80211/ibss.c:1124 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1613 [inline] ieee80211_ibss_rx_queued_mgmt+0x18ae/0x2c80 net/mac80211/ibss.c:1642 ieee80211_iface_process_skb net/mac80211/iface.c:1655 [inline] ieee80211_iface_work+0x717/0xc70 net/mac80211/iface.c:1709 cfg80211_wiphy_work+0x225/0x260 net/wireless/core.c:437 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