INFO: task syz.7.2891:21601 blocked for more than 143 seconds. Tainted: G U L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.2891 state:D stack:29064 pid:21601 tgid:21593 ppid:10976 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776 fdget_pos+0x2a2/0x370 fs/file.c:1255 class_fd_pos_constructor include/linux/file.h:85 [inline] ksys_write+0x71/0x250 fs/read_write.c:729 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f827ab8f7c9 RSP: 002b:00007f827b9a2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f827ade6180 RCX: 00007f827ab8f7c9 RDX: 00000000000098c7 RSI: 0000200000000440 RDI: 0000000000000004 RBP: 00007f827ac13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f827ade6218 R14: 00007f827ade6180 R15: 00007ffed38a6438 Showing all locks held in the system: 2 locks held by kworker/0:0/9: 4 locks held by kworker/0:1/10: 1 lock held by khungtaskd/31: #0: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c9520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by acpid/5184: #0: ffff888027e42160 (&mousedev->mutex#2){+.+.}-{4:4}, at: mousedev_close_device+0x21/0xd0 drivers/input/mousedev.c:441 #1: ffff888091ca02c0 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #1: ffff888091ca02c0 (&dev->mutex#2){+.+.}-{4:4}, at: input_close_device+0x46/0x2a0 drivers/input/input.c:646 #2: ffffffff8e3d4c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 4 locks held by syz-executor/5815: #0: ffff88801267e808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x117/0x580 mm/mmap_lock.c:259 #1: ffff88814e112518 (sb_pagefaults){.+.+}-{0:0}, at: do_page_mkwrite+0x174/0x380 mm/memory.c:3528 #2: ffff8880461798c0 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #2: ffff8880461798c0 (mapping.invalidate_lock#2){++++}-{4:4}, at: ext4_page_mkwrite+0x353/0x1880 fs/ext4/inode.c:6670 #3: ffff8880461795b0 (&ei->i_data_sem){++++}-{4:4}, at: ext4_da_map_blocks fs/ext4/inode.c:1961 [inline] #3: ffff8880461795b0 (&ei->i_data_sem){++++}-{4:4}, at: ext4_da_get_block_prep+0x6ad/0x1230 fs/ext4/inode.c:2027 2 locks held by kworker/0:9/10942: 3 locks held by kworker/u11:0/11409: 4 locks held by kworker/u10:1/11410: 4 locks held by kworker/u10:2/11411: 4 locks held by kworker/u10:4/11414: 3 locks held by kworker/u10:6/11418: 3 locks held by kworker/u10:7/11425: 3 locks held by kworker/u10:9/11432: 4 locks held by kworker/u11:1/11436: 4 locks held by kworker/u10:18/11673: 3 locks held by kworker/u10:19/11674: 4 locks held by kworker/u10:20/11675: 4 locks held by kworker/u10:21/11678: 3 locks held by kworker/u10:22/11679: 3 locks held by kworker/u10:24/14093: 4 locks held by kworker/u10:27/14096: 3 locks held by kworker/u10:30/14398: 4 locks held by kworker/u10:31/14399: 4 locks held by kworker/u10:32/14400: 4 locks held by kworker/u10:33/14401: 3 locks held by kworker/u10:35/14995: 3 locks held by kworker/u10:36/14996: 4 locks held by kworker/u10:39/15315: 4 locks held by kworker/u10:40/15317: 3 locks held by kworker/u10:41/15318: 2 locks held by getty/18130: #0: ffff88814d5a20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000d7132f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211 3 locks held by kworker/u10:44/20610: 3 locks held by kworker/u10:45/20611: 3 locks held by kworker/u10:46/20612: 3 locks held by kworker/u10:47/20614: 3 locks held by kworker/u10:48/20615: #0: ffff88814c75f148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc90004c4fc90 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734 3 locks held by kworker/u10:49/20616: 2 locks held by syz.0.2899/21592: #0: ffffffff9012eb50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577 #1: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #1: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7e9/0xab0 net/core/net_namespace.c:248 7 locks held by syz.7.2891/21598: #0: ffff8880291ad438 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1255 #1: ffff8880347b0420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738 #2: ffff88807f036088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x570 fs/kernfs/file.c:343 #3: ffff88802adc90f8 (kn->active#138){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #3: ffff88802adc90f8 (kn->active#138){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2ff/0x570 fs/kernfs/file.c:344 #4: ffff88802acce710 (&atkbd->mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline] #4: ffff88802acce710 (&atkbd->mutex){+.+.}-{4:4}, at: atkbd_attr_set_helper.isra.0+0x31/0x260 drivers/input/keyboard/atkbd.c:1463 #5: ffffffff8f966568 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #5: ffffffff8f966568 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x184/0x4d0 drivers/input/input.c:2187 #6: ffffffff8e3d4c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by syz.7.2891/21601: #0: ffff8880291ad438 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1255 3 locks held by kworker/0:8/21606: #0: ffff88813ff56948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000504fc90 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x91/0x1190 net/wireless/reg.c:2453 3 locks held by kworker/u11:3/21636: 3 locks held by kworker/u11:4/21637: #0: ffff88807f3a1148 ((wq_completion)hci11){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc900046dfc90 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88807e610ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open+0x22/0xb0 net/bluetooth/hci_core.c:428 3 locks held by kworker/u11:5/21638: #0: ffff888033d71948 ((wq_completion)hci12){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000b677c90 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff888062d90ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open+0x22/0xb0 net/bluetooth/hci_core.c:428 1 lock held by syz-executor/21641: #0: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 1 lock held by syz-executor/21645: #0: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff90145328 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x1540 net/ipv4/devinet.c:978 2 locks held by kworker/u11:7/21661: 3 locks held by kworker/u11:8/21662: 5 locks held by kworker/u11:9/21673: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 21673 Comm: kworker/u11:9 Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: hci14 hci_rx_work RIP: 0010:__lock_acquire+0x8a/0x2890 kernel/locking/lockdep.c:5106 Code: 89 c8 45 85 db 74 5d 48 3d 10 16 b9 93 74 55 8b 15 3b 5e 28 19 85 d2 0f 94 c0 41 89 c6 83 fd 07 76 08 84 c0 0f 85 19 09 00 00 <83> fd 01 76 3a 31 d2 89 ee 4c 89 ef 44 89 44 24 10 89 4c 24 08 e8 RSP: 0018:ffffc90000006b88 EFLAGS: 00000097 RAX: ffffffff9b0b7c01 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888026630e58 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000001 R12: ffff888034089e80 R13: ffff888026630e58 R14: 000000009b0b7c01 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881248fc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555c0d80aa38 CR3: 000000000e184000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3f/0x70 kernel/locking/spinlock.c:252 ebt_do_table+0xe8/0x2190 net/bridge/netfilter/ebtables.c:211 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623 nf_hook+0x45e/0x780 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] br_forward_finish+0xcd/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167 br_nf_forward_finish+0x66a/0xba0 net/bridge/br_netfilter_hooks.c:662 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_forward_ip.part.0+0x609/0x810 net/bridge/br_netfilter_hooks.c:716 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:676 [inline] br_nf_forward+0xf0f/0x1be0 net/bridge/br_netfilter_hooks.c:773 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623 nf_hook+0x45e/0x780 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] __br_forward+0x1be/0x5b0 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xf1/0x180 net/bridge/br_forward.c:191 br_flood+0x17c/0x650 net/bridge/br_forward.c:238 br_handle_frame_finish+0x1117/0x1f00 net/bridge/br_input.c:229 br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167 br_nf_pre_routing_finish_ipv6+0x76a/0xfc0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0xb28/0x14e0 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0x6b3/0x35b0 net/core/dev.c:6026 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6137 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6252 process_backlog+0x4a2/0x1650 net/core/dev.c:6604 __napi_poll.constprop.0+0xb3/0x540 net/core/dev.c:7668 napi_poll net/core/dev.c:7731 [inline] net_rx_action+0x9f9/0xfa0 net/core/dev.c:7883 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline] RIP: 0010:vprintk_emit+0x556/0x6b0 kernel/printk/printk.c:2425 Code: 00 4d 85 ed 0f 85 19 01 00 00 e8 e5 c2 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 a3 bd 21 00 48 85 ed 0f 85 25 01 00 00 c5 c2 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc90002f17798 EFLAGS: 00000283 RAX: 00000000000155b0 RBX: 0000000000000036 RCX: ffffc9001724a000 RDX: 0000000000100000 RSI: ffffffff819ca935 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: ffff88803408a9b0 R12: 1ffff920005e2ef5 R13: 0000000000000200 R14: ffff88801eeabd00 R15: ffffc90002f17860 _printk+0xc7/0x100 kernel/printk/printk.c:2451 bt_warn+0xe4/0x120 net/bluetooth/lib.c:276 hci_cc_func net/bluetooth/hci_event.c:4229 [inline] hci_cmd_complete_evt+0x2e4/0xa40 net/bluetooth/hci_event.c:4253 hci_event_func net/bluetooth/hci_event.c:7716 [inline] hci_event_packet+0x685/0x1210 net/bluetooth/hci_event.c:7773 hci_rx_work+0x2c9/0x1020 net/bluetooth/hci_core.c:4076 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246