INFO: task syz.4.96:4641 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.96 state:D stack:25872 pid: 4641 ppid: 4192 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 perf_pending_task_sync+0x13c/0x1c0 kernel/events/core.c:5127 _free_event+0x34/0xe30 kernel/events/core.c:5133 put_event kernel/events/core.c:5258 [inline] perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5383 perf_release+0x37/0x40 kernel/events/core.c:5393 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x635/0x2110 kernel/exit.c:884 do_group_exit+0x12c/0x2f0 kernel/exit.c:998 get_signal+0x7eb/0x12e0 kernel/signal.c:2901 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3c89dc4e99 RSP: 002b:00007f3c87ffc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f3c8a04d090 RCX: 00007f3c89dc4e99 RDX: 0000200000000080 RSI: 00000000000089f1 RDI: 0000000000000005 RBP: 00007f3c89e5aeaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3c8a04d128 R14: 00007f3c8a04d090 R15: 00007ffe0cf5e218 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/u4:3/155: 2 locks held by getty/3946: #0: ffff88802c3ea098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 3 locks held by kworker/u4:6/4520: #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc9000335fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffffffff8c3238f0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0xa1/0x4c0 kernel/rcu/tree.c:4043 2 locks held by kworker/1:10/5239: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90002e9fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 3 locks held by syz.7.587/7224: 3 locks held by syz-executor/7551: #0: ffff888074ec13f0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1020 net/bluetooth/hci_core.c:1755 #1: ffff888074ec0478 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x408/0x1020 net/bluetooth/hci_core.c:1800 #2: ffffffff8d5933e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1519 [inline] #2: ffffffff8d5933e8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622 2 locks held by syz.2.648/7557: 1 lock held by syz.6.657/7619: #0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 1 lock held by syz.8.661/7646: #0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #0: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 2 locks held by sed/7660: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7224 Comm: syz.7.587 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline] RIP: 0010:write_comp_data kernel/kcov.c:227 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x13/0x80 kernel/kcov.c:300 Code: 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 65 48 8b 0d 54 6a 89 7e 65 8b 15 55 6a 89 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 34 16 00 00 RSP: 0018:ffffc90000007d98 EFLAGS: 00000046 RAX: ffffffff8168f7bf RBX: 0000000000000046 RCX: ffff888024f80000 RDX: 0000000080010001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000007e50 R08: ffffffff8d8b0def R09: 1ffffffff1b161bd R10: dffffc0000000000 R11: fffffbfff1b161be R12: 0000000000000000 R13: dffffc0000000000 R14: 1ffff92000000fb4 R15: dffffc0000000000 FS: 00007fa7869056c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4e97be97e8 CR3: 000000007315b000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:127 [inline] arch_irqs_disabled arch/x86/include/asm/irqflags.h:134 [inline] seqcount_lockdep_reader_access+0x15f/0x1d0 include/linux/seqlock.h:105 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get_update_offsets_now+0x95/0x3e0 kernel/time/timekeeping.c:2303 hrtimer_update_base kernel/time/hrtimer.c:621 [inline] hrtimer_interrupt+0x121/0x8b0 kernel/time/hrtimer.c:1793 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__sanitizer_cov_trace_pc+0x41/0x60 kernel/kcov.c:211 Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 14 16 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 RSP: 0018:ffffc900034bf778 EFLAGS: 00000246 RAX: ffffffff88678b6d RBX: 0000000000000001 RCX: ffff888024f80000 RDX: ffffc9000fbd1000 RSI: 000000000007ffff RDI: 0000000000000000 RBP: ffffc900034bf870 R08: dffffc0000000000 R09: 1ffffffff203dc18 R10: dffffc0000000000 R11: fffffbfff203dc19 R12: dffffc0000000000 R13: dffffc0000000000 R14: 00000000000f01dd R15: ffffffff8d628948 inet_twsk_purge+0x4dd/0x820 net/ipv4/inet_timewait_sock.c:270 ops_exit_list net/core/net_namespace.c:177 [inline] setup_net+0x842/0xa10 net/core/net_namespace.c:365 copy_net_ns+0x33e/0x5b0 net/core/net_namespace.c:503 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110 copy_namespaces+0x378/0x3d0 kernel/nsproxy.c:178 copy_process+0x1844/0x3ec0 kernel/fork.c:2294 kernel_clone+0x23f/0x990 kernel/fork.c:2681 __do_sys_clone kernel/fork.c:2798 [inline] __se_sys_clone kernel/fork.c:2782 [inline] __x64_sys_clone+0x19a/0x210 kernel/fork.c:2782 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa7886ace99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa786904fd8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fa788934fa0 RCX: 00007fa7886ace99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000c2002000 RBP: 00007fa788742eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007fa788935038 R14: 00007fa788934fa0 R15: 00007ffc572dfb68