rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=96b/1/0x4000000000000000 softirq=101911/101912 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P27518/1:b..l (detected by 0, t=10502 jiffies, g=146877, q=101) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 32267 Comm: syz-executor.1 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_cmp8+0xc/0x70 kernel/kcov.c:266 Code: 4c 38 f0 48 c7 44 38 e0 04 00 00 00 48 89 74 38 e8 4e 89 54 c8 20 48 89 10 c3 0f 1f 40 00 49 89 f8 bf 03 00 00 00 4c 8b 14 24 <48> 89 f1 65 48 8b 34 25 00 70 02 00 e8 c3 f7 ff ff 84 c0 74 48 48 RSP: 0018:ffffc90000dc0dd0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff888048c9d340 RCX: 0000000000000000 RDX: 1ffff11009193a68 RSI: ffff888048c9d340 RDI: 0000000000000003 RBP: ffff8880b9d2a750 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8402920c R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880b9d2a600 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555562b5708 CR3: 0000000022436000 CR4: 0000000000350ee0 Call Trace: timerqueue_del+0x3c/0x140 lib/timerqueue.c:55 __remove_hrtimer+0xa1/0x2a0 kernel/time/hrtimer.c:1116 __run_hrtimer kernel/time/hrtimer.c:1665 [inline] __hrtimer_run_queues+0x4ea/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:lock_release+0x5e/0x720 kernel/locking/lockdep.c:5647 Code: 03 48 c7 44 24 18 a8 98 39 8b 48 01 e8 48 c7 44 24 20 30 35 5d 81 c7 00 f1 f1 f1 f1 c7 40 04 f1 f1 04 f2 c7 40 08 04 f3 f3 f3 <65> 48 8b 04 25 28 00 00 00 48 89 84 24 88 00 00 00 31 c0 0f 1f 44 RSP: 0018:ffffc900038e76d8 EFLAGS: 00000286 RAX: fffff5200071cedd RBX: 0000000000000000 RCX: ffffffff81c4e3db RDX: 0000000000000000 RSI: ffffffff81c5c18f RDI: ffffffff8bb852e0 RBP: 1ffff9200071cedd R08: 0000000000000000 R09: ffffea0001eb1607 R10: fffff940003d62c0 R11: 0000000000000000 R12: ffffffff8bb852e0 R13: ffff88804d4eb478 R14: dffffc0000000000 R15: 00007f4ec1690000 zap_pte_range mm/memory.c:1380 [inline] zap_pmd_range mm/memory.c:1490 [inline] zap_pud_range mm/memory.c:1519 [inline] zap_p4d_range mm/memory.c:1540 [inline] unmap_page_range+0xf7f/0x2a30 mm/memory.c:1561 unmap_single_vma+0x198/0x310 mm/memory.c:1606 unmap_vmas+0x16b/0x2f0 mm/memory.c:1638 exit_mmap+0x201/0x670 mm/mmap.c:3179 __mmput+0x122/0x4b0 kernel/fork.c:1116 mmput+0x56/0x60 kernel/fork.c:1137 exit_mm kernel/exit.c:507 [inline] do_exit+0xb27/0x2b40 kernel/exit.c:819 do_group_exit+0x125/0x310 kernel/exit.c:929 get_signal+0x47d/0x2220 kernel/signal.c:2852 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4ec1b38fe9 Code: Unable to access opcode bytes at RIP 0x7f4ec1b38fbf. RSP: 002b:00007f4ec04ae218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f4ec1c4bf68 RCX: 00007f4ec1b38fe9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f4ec1c4bf68 RBP: 00007f4ec1c4bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4ec1c4bf6c R13: 00007ffde84ee29f R14: 00007f4ec04ae300 R15: 0000000000022000 task:udevd state:R running task stack:25312 pid:27518 ppid: 2969 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4f00 kernel/sched/core.c:6296 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6462 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x57/0x70 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:404 [inline] __wake_up_common_lock+0xde/0x130 kernel/sched/wait.c:140 sock_def_readable+0xec/0x4e0 net/core/sock.c:3142 unix_dgram_sendmsg+0xf30/0x1a10 net/unix/af_unix.c:2029 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 sock_write_iter+0x289/0x3c0 net/socket.c:1061 call_write_iter include/linux/fs.h:2086 [inline] new_sync_write+0x431/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x1ee/0x250 fs/read_write.c:643 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: 0033:0x7f1e372249a3 RSP: 002b:00007ffeb22245b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1e372249a3 RDX: 0000000000000000 RSI: 00007ffeb222460f RDI: 000000000000000a RBP: 00007ffeb222460f R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000010 R11: 0000000000000246 R12: 000000000000000a R13: 00007f1e370cd6a8 R14: 0000000000000000 R15: 000055b306e38910 rcu: rcu_preempt kthread starved for 10500 jiffies! g146877 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28728 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4f00 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136 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: 4018 Comm: kworker/u4:8 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:458 print_other_cpu_stall kernel/rcu/tree_stall.h:563 [inline] check_cpu_stall kernel/rcu/tree_stall.h:706 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq+0x1f7c/0x2150 kernel/rcu/tree.c:2617 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:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:200 Code: 00 00 e9 76 f0 64 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 c9 23 8a 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 00 70 02 00 a9 00 01 ff 00 74 0e RSP: 0018:ffffc9000283f9f8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffff8880b9d3e9c0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff816ccf90 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff816ccfb6 R11: 0000000000000000 R12: ffffed10173a7d39 R13: 0000000000000001 R14: ffff8880b9d3e9c8 R15: 0000000000000001 rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] csd_lock_wait kernel/smp.c:440 [inline] smp_call_function_many_cond+0x450/0xc20 kernel/smp.c:969 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+0x1b1/0x510 arch/x86/kernel/alternative.c:1300 text_poke_flush arch/x86/kernel/alternative.c:1470 [inline] text_poke_flush arch/x86/kernel/alternative.c:1467 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1477 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+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 4c 38 f0 rex.WR cmp %r14b,%al 3: 48 c7 44 38 e0 04 00 movq $0x4,-0x20(%rax,%rdi,1) a: 00 00 c: 48 89 74 38 e8 mov %rsi,-0x18(%rax,%rdi,1) 11: 4e 89 54 c8 20 mov %r10,0x20(%rax,%r9,8) 16: 48 89 10 mov %rdx,(%rax) 19: c3 retq 1a: 0f 1f 40 00 nopl 0x0(%rax) 1e: 49 89 f8 mov %rdi,%r8 21: bf 03 00 00 00 mov $0x3,%edi 26: 4c 8b 14 24 mov (%rsp),%r10 * 2a: 48 89 f1 mov %rsi,%rcx <-- trapping instruction 2d: 65 48 8b 34 25 00 70 mov %gs:0x27000,%rsi 34: 02 00 36: e8 c3 f7 ff ff callq 0xfffff7fe 3b: 84 c0 test %al,%al 3d: 74 48 je 0x87 3f: 48 rex.W