INFO: task syz.0.2370:15538 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2370 state:D stack:28272 pid:15538 tgid:15534 ppid:5594 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x1259/0x6920 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7362 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xcbf/0x1bc0 kernel/locking/mutex.c:821 fdget_pos+0x2aa/0x380 fs/file.c:1259 class_fd_pos_constructor include/linux/file.h:85 [inline] ksys_read+0x71/0x250 fs/read_write.c:707 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f274439e0d9 RSP: 002b:00007f2745305028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f2744626090 RCX: 00007f274439e0d9 RDX: 0000000000002000 RSI: 0000200000004000 RDI: 0000000000000009 RBP: 00007f2744435024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2744626128 R14: 00007f2744626090 R15: 00007ffd2ffc2b98 Showing all locks held in the system: locks held by khungtaskd/30: 1, last CPU#0: #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ede9de0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6793 locks held by getty/5350: 2, on CPU#1: #0: ffff888033c350a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 locks held by kworker/u8:15/8189: 5, on CPU#0: #0: ffff88801d2d8940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc90002fdfd08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffffffff90cabc68 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:677 #3: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: wiphy_unregister+0x13d/0xc80 net/wireless/core.c:1304 #4: ffff8880334007a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: wiphy_lock include/net/cfg80211.h:6890 [inline] #4: ffff8880334007a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: wiphy_unregister+0x147/0xc80 net/wireless/core.c:1305 locks held by kworker/u8:21/14041: 3, on CPU#0: #0: ffff88801c08c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3362 #1: ffffc9000e02fd08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3363 #2: ffffffff90cc4740 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313 locks held by syz.0.2370/15535: 3, last CPU#1: #0: ffff888073e3f5f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 #1: ffff888090150088 (&iter->mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline] #1: ffff888090150088 (&iter->mutex){+.+.}-{4:4}, at: tracing_read_pipe+0x6c/0xd60 kernel/trace/trace.c:5405 #2: ffff88801c08d030 (buffer->reader_lock_key#2){....}-{2:2}, at: tracing_read_pipe+0x4b2/0xd60 kernel/trace/trace.c:5440 locks held by syz.0.2370/15538: 1, on CPU#1: #0: ffff888073e3f5f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259 locks held by syz-executor/15792: 1, on CPU#1: #0: ffff88807e61cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 locks held by syz-executor/16537: 1, on CPU#1: #0: ffffffff8edf5ce8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 locks held by syz.5.2609/16693: 1, on CPU#0: #0: ffff888069234ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 locks held by syz.3.2610/16695: 1, on CPU#1: #0: ffff88807cff0ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500 locks held by dhcpcd-run-hook/16709: 5, last CPU#1: #0: ffff8880b843bf60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:685 [inline] #0: ffff8880b843bf60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:669 #1: ffff8880b8524568 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:218 [inline] #1: ffff8880b8524568 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2e0c/0x6920 kernel/sched/core.c:7264 #2: ffffffff9bbf0768 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x144/0x4b0 lib/debugobjects.c:873 #3: ffff88802673b018 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:594 [inline] #3: ffff88802673b018 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xc1/0x1c90 kernel/sched/core.c:4302 #4: ffff8880b8524568 (psi_seq){-.-.}-{0:0}, at: psi_enqueue kernel/sched/stats.h:159 [inline] (psi_seq){-.-.}-{0:0}, at: enqueue_task+0x1dc/0x4f0 kernel/sched/core.c:2196 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 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: 16537 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 RIP: 0010:__lock_acquire+0x132/0x1ec0 kernel/locking/lockdep.c:5186 Code: 44 24 08 75 20 49 8d b4 0c 80 0b 00 00 0f b7 46 20 25 ff 1f 00 00 39 e8 75 0b 48 83 3c 24 00 0f 85 db 05 00 00 48 8b 44 24 08 <89> ea 66 81 e2 ff 1f 48 8d 1c 08 0f b7 43 20 4c 89 7b 10 66 25 00 RSP: 0018:ffffc90000a08d70 EFLAGS: 00000016 RAX: ffff88807e7956a8 RBX: 0000000000000000 RCX: 0000000000000028 RDX: 0000000000000000 RSI: ffff88807e7956a8 RDI: ffffffff9b982188 RBP: 0000000000000057 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000001 R12: ffff88807e794b00 R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff9b982188 FS: 0000000000000000(0000) GS:ffff888123c79000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560034aa0b11 CR3: 000000000eb94000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5886 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843 seqcount_lockdep_reader_access include/linux/seqlock.h:73 [inline] ktime_get_update_offsets_now+0x8f/0x500 kernel/time/timekeeping.c:2856 hrtimer_update_base kernel/time/hrtimer.c:686 [inline] hrtimer_interrupt+0x1ca/0xaa0 kernel/time/hrtimer.c:2226 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:153 [inline] RIP: 0010:_raw_spin_lock_irqsave+0xa/0x60 kernel/locking/spinlock.c:181 Code: e8 5b bd 44 f6 eb c9 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 53 48 89 fb 9c <5d> fa f7 c5 00 02 00 00 75 39 bf 01 00 00 00 e8 12 6b 07 f6 ff 74 RSP: 0018:ffffc900049f7720 EFLAGS: 00000282 RAX: fffffbfff3768d8c RBX: ffffffff9bb46c68 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffff88805c865000 RDI: ffffffff9bb46c68 RBP: ffffc900049f7870 R08: ffffffff9bb46c60 R09: 0000000000000a00 R10: 0000000000005000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff88805c864000 R14: ffffffff9bb46c60 R15: 0000000000000a00 __debug_check_no_obj_freed lib/debugobjects.c:1160 [inline] debug_check_no_obj_freed+0x1c9/0x630 lib/debugobjects.c:1201 __free_pages_prepare mm/page_alloc.c:1425 [inline] free_pages_prepare+0x3a7/0xe00 mm/page_alloc.c:1463 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:7060 __free_contig_range mm/page_alloc.c:7105 [inline] free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5322 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3462 vfree mm/vmalloc.c:3511 [inline] vfree+0x108/0x730 mm/vmalloc.c:3485 kcov_put kernel/kcov.c:449 [inline] kcov_put kernel/kcov.c:445 [inline] kcov_close+0x34/0x60 kernel/kcov.c:556 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x951/0x2ae0 kernel/exit.c:1008 do_group_exit+0xd5/0x2a0 kernel/exit.c:1151 get_signal+0x1ec7/0x21e0 kernel/signal.c:3039 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x700 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] do_syscall_64+0x661/0x790 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1d6455e90e Code: Unable to access opcode bytes at 0x7f1d6455e8e4. RSP: 002b:00007ffc26d83888 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: 000000000000004c RBX: 0000555571ffb500 RCX: 00007f1d6455e90e RDX: 000000000000004c RSI: 00007f1d65354670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffc26d83904 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f1d65354670 R15: 0000000000000000