rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=fad/1/0x4000000000000000 softirq=64240/64241 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3937/1:b..l (detected by 0, t=10502 jiffies, g=94725, q=116) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3633 Comm: syz-executor.3 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data kernel/kcov.c:221 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x15/0x80 kernel/kcov.c:273 Code: 00 48 89 4c 38 f0 4e 89 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 40 70 02 00 <48> 89 ce 4c 8b 54 24 08 e8 4e f7 ff ff 84 c0 74 51 48 8b 81 88 15 RSP: 0018:ffffc900028af478 EFLAGS: 00000046 RAX: 0000000000000005 RBX: ffffffff89accdcc RCX: ffff88807dcc1d00 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000003 RBP: ffffc900028af5a0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8401183b R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff89accdcb R14: 1ffff92000515e94 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f045465d2a0 CR3: 0000000044339000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: format_decode+0x180/0xad0 lib/vsprintf.c:2539 vsnprintf+0x155/0x14f0 lib/vsprintf.c:2757 sprintf+0xc0/0x100 lib/vsprintf.c:3007 print_time kernel/printk/printk.c:1261 [inline] info_print_prefix+0x248/0x340 kernel/printk/printk.c:1287 record_print_text+0x14d/0x3e0 kernel/printk/printk.c:1336 console_unlock+0x2d8/0xb70 kernel/printk/printk.c:2692 vprintk_emit+0x198/0x4f0 kernel/printk/printk.c:2245 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 _printk+0xba/0xed kernel/printk/printk.c:2266 stack_trace_print kernel/stacktrace.c:33 [inline] stack_trace_print.cold+0x3b/0x5a kernel/stacktrace.c:24 ref_tracker_dir_exit.cold+0x84/0x1e3 lib/ref_tracker.c:32 __put_net+0x15/0x70 net/core/net_namespace.c:640 put_net include/net/net_namespace.h:268 [inline] put_net_track include/net/net_namespace.h:342 [inline] __sk_destruct+0x6d2/0x920 net/core/sock.c:2042 sk_destruct+0xbd/0xe0 net/core/sock.c:2058 __sk_free+0xef/0x3d0 net/core/sock.c:2069 sk_free+0x78/0xa0 net/core/sock.c:2080 sock_put include/net/sock.h:1912 [inline] __tun_detach+0xdb4/0x13e0 drivers/net/tun.c:681 tun_detach drivers/net/tun.c:693 [inline] tun_chr_close+0xc4/0x180 drivers/net/tun.c:3405 __fput+0x286/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xc14/0x2b40 kernel/exit.c:832 do_group_exit+0x125/0x310 kernel/exit.c:929 __do_sys_exit_group kernel/exit.c:940 [inline] __se_sys_exit_group kernel/exit.c:938 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:938 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fe3a4e6afe9 Code: Unable to access opcode bytes at RIP 0x7fe3a4e6afbf. RSP: 002b:00007fffd84d7dd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fffd84d7f80 RCX: 00007fe3a4e6afe9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 0000000000000000 R08: 0000000000000025 R09: 00007fffd84d7f80 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe3a4ec505e R13: 000000000000001c R14: 000000000000000d R15: 00007fffd84d7fc0 task:kworker/u4:8 state:R running task stack:26232 pid: 3937 ppid: 2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4900 kernel/sched/core.c:6253 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6668 irqentry_exit+0x31/0x80 kernel/entry/common.c:425 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5605 Code: e7 a5 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90002cbfa58 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000597f4d RCX: dd891d131293d03c RDX: 1ffff11009d2c14b RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ffa2a07 R10: fffffbfff1ff4540 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bb84620 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:688 [inline] inet_twsk_purge+0x117/0x7d0 net/ipv4/inet_timewait_sock.c:268 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:595 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g94725 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=49419 rcu: rcu_preempt kthread starved for 10502 jiffies! g94725 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack:28712 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4900 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 0 CPU: 0 PID: 10 Comm: kworker/u4:1 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline] check_cpu_stall kernel/rcu/tree_stall.h:729 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq+0x1f7c/0x2150 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline] RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:969 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 90 7a 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31 RSP: 0018:ffffc90000cf79f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9d3fca0 RCX: 0000000000000000 RDX: ffff888010e41d00 RSI: ffffffff816bfc60 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816bfc86 R11: 0000000000000000 R12: ffffed10173a7f95 R13: 0000000000000001 R14: ffff8880b9d3fca8 R15: 0000000000000001 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1112 [inline] text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1297 text_poke_flush arch/x86/kernel/alternative.c:1451 [inline] text_poke_flush arch/x86/kernel/alternative.c:1448 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1458 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1da/0x400 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:734 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:726 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 00 48 89 add %cl,-0x77(%rax) 3: 4c 38 f0 rex.WR cmp %r14b,%al 6: 4e 89 54 c8 20 mov %r10,0x20(%rax,%r9,8) b: 48 89 10 mov %rdx,(%rax) e: c3 retq f: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 15: 53 push %rbx 16: 41 89 fb mov %edi,%r11d 19: 41 89 f1 mov %esi,%r9d 1c: bf 03 00 00 00 mov $0x3,%edi 21: 65 48 8b 0c 25 40 70 mov %gs:0x27040,%rcx 28: 02 00 * 2a: 48 89 ce mov %rcx,%rsi <-- trapping instruction 2d: 4c 8b 54 24 08 mov 0x8(%rsp),%r10 32: e8 4e f7 ff ff callq 0xfffff785 37: 84 c0 test %al,%al 39: 74 51 je 0x8c 3b: 48 rex.W 3c: 8b .byte 0x8b 3d: 81 .byte 0x81 3e: 88 .byte 0x88 3f: 15 .byte 0x15