INFO: task udevd:6666 blocked for more than 155 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23248 pid:6666 tgid:6666 ppid:5235 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 inode_lock include/linux/fs.h:980 [inline] open_last_lookups fs/namei.c:3892 [inline] path_openat+0x8da/0x3830 fs/namei.c:4131 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb48f4a7407 RSP: 002b:00007fffb4352700 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb48fc9a880 RCX: 00007fb48f4a7407 RDX: 0000000000080241 RSI: 00007fffb4352c60 RDI: ffffffffffffff9c RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000202 R12: 0000563ada000dfc R13: 0000563ada000dfc R14: 0000000000000001 R15: 0000563ada01b140 Showing all locks held in the system: 1 lock held by kthreadd/2: 4 locks held by kworker/R-kvfre/6: 4 locks held by kworker/0:0/9: 2 locks held by kworker/0:1/10: 3 locks held by kworker/u8:0/12: 3 locks held by kworker/u8:1/13: 2 locks held by kworker/1:0/24: 1 lock held by khungtaskd/31: #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/36: 1 lock held by khugepaged/38: #0: ffffffff8e4043a8 (lock#5){+.+.}-{4:4}, at: __lru_add_drain_all+0x6b/0x5e0 mm/swap.c:840 3 locks held by kworker/1:1/43: #0: ffff88813fe5a148 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe5a148 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000b37ba0 ((work_completion)(&(&sbi->sync_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000b37ba0 ((work_completion)(&(&sbi->sync_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88802a442998 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_sync_fs+0x266/0x770 fs/hfsplus/super.c:211 4 locks held by kworker/u8:3/50: 3 locks held by kworker/u8:4/60: 3 locks held by kworker/0:1H/97: #0: ffff888140ea2d48 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff888140ea2d48 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90002607ba0 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90002607ba0 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8e342db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 3 locks held by kworker/u8:5/198: 3 locks held by kworker/u8:6/1147: 3 locks held by kworker/u8:7/1151: 3 locks held by kworker/u8:8/1169: 4 locks held by kworker/0:2/1213: 3 locks held by kworker/u8:9/1343: 4 locks held by kworker/R-bat_e/3428: 2 locks held by klogd/5224: 2 locks held by udevd/5235: 1 lock held by dhcpcd/5529: 2 locks held by dhcpcd/5530: 2 locks held by crond/5604: 2 locks held by getty/5619: #0: ffff88814d2bc0a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by sshd-session/5847: 1 lock held by syz-executor/5848: 3 locks held by syz-executor/5863: #0: ffff888024b000e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888024b000e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888024b000e0 (&type->s_umount_key#72){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffff88802a442998 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_sync_fs+0x266/0x770 fs/hfsplus/super.c:211 #2: ffff88802a4428f8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_sync_fs+0x279/0x770 fs/hfsplus/super.c:212 3 locks held by syz-executor/5872: 5 locks held by syz-executor/5878: 1 lock held by kworker/R-wg-cr/5904: #0: ffffffff8e1e3c48 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x2e/0x3a0 kernel/workqueue.c:2678 3 locks held by kworker/0:3/5905: 1 lock held by kworker/R-wg-cr/5906: 1 lock held by kworker/R-wg-cr/5907: #0: ffffffff8e1e3c48 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline] #0: ffffffff8e1e3c48 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x88b/0xdd0 kernel/workqueue.c:3556 1 lock held by kworker/R-wg-cr/5908: #0: ffffffff8e1e3c48 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline] #0: ffffffff8e1e3c48 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x88b/0xdd0 kernel/workqueue.c:3556 2 locks held by kworker/1:3/5915: 3 locks held by kworker/0:4/5946: 2 locks held by kworker/1:6/5949: 2 locks held by kworker/0:5/5974: 2 locks held by kworker/0:6/5976: 3 locks held by kworker/0:7/5977: 2 locks held by udevd/6666: #0: ffff88806a16e420 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline] #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4131 2 locks held by udevd/6684: #0: ffff88806a16e420 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3360 [inline] #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: do_renameat2+0x3b9/0xa50 fs/namei.c:5311 2 locks held by udevd/6695: #0: ffff88806a16e420 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3360 [inline] #1: ffff88802ee9b688 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: do_renameat2+0x3b9/0xa50 fs/namei.c:5311 3 locks held by udevd/6697: 3 locks held by kworker/u8:10/7063: 1 lock held by syz.0.367/7613: 4 locks held by kworker/u8:11/7635: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 3428 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: bat_events batadv_tt_purge RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4315 [inline] RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline] RIP: 0010:lockdep_hardirqs_on_prepare+0xfc/0x2a0 kernel/locking/lockdep.c:4410 Code: 8e d1 00 00 00 49 89 de 49 81 c6 30 0b 00 00 45 31 ff 4d 89 f4 eb 13 49 ff c7 48 63 83 28 0b 00 00 49 83 c4 28 49 39 c7 7d 44 <49> 83 ff 31 73 2d 41 8b 44 24 20 a9 00 00 04 00 74 db 25 00 00 03 RSP: 0018:ffffc90000a07940 EFLAGS: 00000097 RAX: 0000000000000006 RBX: ffff888030b7dac0 RCX: ffffffff93718fc0 RDX: 0000000000000002 RSI: ffff888030b7e618 RDI: ffff888030b7dac0 RBP: ffffc90000a07a10 R08: ffffffff8fc35777 R09: 1ffffffff1f86aee R10: dffffc0000000000 R11: fffffbfff1f86aef R12: ffff888030b7e6b8 R13: ffffffff8a3cb4e2 R14: ffff888030b7e5f0 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffec8d745dc CR3: 00000000312d0000 CR4: 00000000003526f0 Call Trace: trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78 __local_bh_enable_ip+0x12d/0x1c0 kernel/softirq.c:455 local_bh_enable include/linux/bottom_half.h:33 [inline] ip6_pol_route+0x7ef/0x1180 net/ipv6/route.c:2307 pol_lookup_func include/net/ip6_fib.h:617 [inline] fib6_rule_lookup+0x52f/0x6f0 net/ipv6/fib6_rules.c:120 ip6_route_input_lookup net/ipv6/route.c:2338 [inline] ip6_route_input+0x6de/0xad0 net/ipv6/route.c:2641 ip6_rcv_finish+0x141/0x2e0 net/ipv6/ip6_input.c:77 ip_sabotage_in+0x1e1/0x270 net/bridge/br_netfilter_hooks.c:990 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x206/0x3a0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6078 [inline] __netif_receive_skb+0xd3/0x380 net/core/dev.c:6191 netif_receive_skb_internal net/core/dev.c:6277 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6336 NF_HOOK+0xa0/0x390 include/linux/netfilter.h:319 br_handle_frame_finish+0x15c6/0x1c50 net/bridge/br_input.c:235 br_nf_hook_thresh+0x3c6/0x4a0 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x999/0xd60 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:442 __netif_receive_skb_core+0x10b9/0x4380 net/core/dev.c:5965 __netif_receive_skb_one_core net/core/dev.c:6076 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6191 process_backlog+0x60e/0x14f0 net/core/dev.c:6543 __napi_poll+0xc7/0x360 net/core/dev.c:7593 napi_poll net/core/dev.c:7656 [inline] net_rx_action+0x707/0xe30 net/core/dev.c:7783 handle_softirqs+0x286/0x870 kernel/softirq.c:622 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x2a7/0x340 net/batman-adv/translation-table.c:1315 batadv_tt_purge+0x35/0x9e0 net/batman-adv/translation-table.c:3509 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 rescuer_thread+0x53c/0xdd0 kernel/workqueue.c:3523 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245