rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=04d/1/0x4000000000000000 softirq=34718/34718 fqs=37 (t=10501 jiffies g=59629 q=281) rcu: rcu_preempt kthread starved for 10428 jiffies! g59629 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28200 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 13840 Comm: syz-executor.1 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline] RIP: 0010:rcu_lockdep_current_cpu_online kernel/rcu/tree.c:1168 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x21/0x150 kernel/rcu/tree.c:1160 Code: 0f 1f 84 00 00 00 00 00 90 65 8b 15 d9 3f 9f 7e 81 e2 00 00 f0 00 b8 01 00 00 00 75 0a 8b 15 ca fc 2d 0c 85 d2 75 01 c3 55 53 <65> ff 05 b8 3f 9f 7e e8 a3 0c e1 07 48 c7 c3 00 a9 03 00 83 f8 07 RSP: 0018:ffffc90000dc0af8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff815cbf11 RDX: 0000000000000001 RSI: 0000000000010003 RDI: ffffffff8b5628a8 RBP: 1ffff920001b8166 R08: 0000000000000000 R09: ffffffff8d912c17 R10: fffffbfff1b22582 R11: 0000000000000000 R12: 0000000000000001 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b9d2a480 FS: 00007f4b649c6700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555576e848 CR3: 000000007be8f000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:112 [inline] rcu_read_lock_held_common kernel/rcu/update.c:102 [inline] rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:123 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5648 seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get+0x158/0x470 kernel/time/timekeeping.c:829 hrtimer_forward_now include/linux/hrtimer.h:506 [inline] perf_swevent_hrtimer+0x246/0x3f0 kernel/events/core.c:10605 __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:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3ba/0xb40 kernel/locking/qspinlock.c:508 Code: eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 <41> 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 38 d8 7f 08 84 c0 0f RSP: 0018:ffffc90005dd7560 EFLAGS: 00000206 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffffffff1867b70 RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffffff8c33db80 R08: 0000000000000001 R09: ffffffff8ff73a47 R10: 0000000000000001 R11: 0000000000000000 R12: 00000000000021f9 R13: fffffbfff1867b70 R14: 0000000000000001 R15: ffff8880b9d3a880 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:349 [inline] proc_keys_start+0x4d/0x450 security/keys/proc.c:118 seq_read_iter+0x2c7/0x1240 fs/seq_file.c:225 proc_reg_read_iter+0x1fb/0x2d0 fs/proc/inode.c:300 call_read_iter include/linux/fs.h:2156 [inline] io_iter_do_read fs/io_uring.c:3501 [inline] io_read+0x33c/0xff0 fs/io_uring.c:3558 io_issue_sqe+0x800/0x7060 fs/io_uring.c:6671 __io_queue_sqe fs/io_uring.c:7018 [inline] io_queue_sqe fs/io_uring.c:7060 [inline] io_submit_sqe fs/io_uring.c:7263 [inline] io_submit_sqes+0x1bca/0x8a20 fs/io_uring.c:7369 __do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10070 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: 0033:0x7f4b66050e99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4b649c6168 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007f4b66163f60 RCX: 00007f4b66050e99 RDX: 0000000000000000 RSI: 00000000000002ff RDI: 0000000000000004 RBP: 00007f4b660ab031 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4b66697b1f R14: 00007f4b649c6300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 13841 Comm: syz-executor.2 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 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+0x40/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:div_u64_rem include/linux/math64.h:29 [inline] RIP: 0010:div_u64 include/linux/math64.h:128 [inline] RIP: 0010:pie_calculate_probability+0x27d/0x7c0 net/sched/sch_pie.c:348 Code: 89 c6 4c 89 6c 24 38 e8 81 20 1a fa 47 8d 24 a4 31 d2 4c 89 ff 43 8d 0c 24 48 c1 ed 02 48 b8 ff ff ff ff ff ff ff 00 48 f7 f1 <49> 89 c5 48 89 c6 48 c1 eb 02 49 89 cc e8 c1 23 1a fa 4d 39 ef 73 RSP: 0018:ffffc90000007c50 EFLAGS: 00000207 RAX: 00000001ad7f29ab RBX: 0000000000abcc77 RCX: 0000000000989680 RDX: 000000000078f87f RSI: ffffffff875d8a6f RDI: 0000000000000000 RBP: 0000000000044b82 R08: 00000000000f4240 R09: 0000000000000000 R10: ffffffff875d8ab6 R11: 0000000000000000 R12: 00000000004c4b40 R13: 00000010c6f7a0b5 R14: 0000000000000001 R15: 0000000000000000 fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x4c/0x60 kernel/kcov.c:205 Code: 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b 82 80 15 00 00 83 f8 02 75 20 48 8b 8a 88 15 00 00 8b 92 84 15 00 00 48 8b 01 <48> 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 c3 0f 1f 00 41 55 RSP: 0018:ffffc900070072b8 EFLAGS: 00000246 RAX: 000000000003ffff RBX: 0000000000000000 RCX: ffffc90002fe2000 RDX: 0000000000040000 RSI: ffffffff84002a04 RDI: 0000000000000003 RBP: ffffc900070073d8 R08: ffffffff8a08bb20 R09: 0000000000000000 R10: ffffffff840029f6 R11: 0000000000000074 R12: 0000000000000064 R13: ffffffff89fd1e54 R14: 1ffff92000e00e5b R15: 0000000000000035 format_decode+0x444/0xad0 lib/vsprintf.c:2670 vsnprintf+0x157/0x14f0 lib/vsprintf.c:2757 seq_vprintf fs/seq_file.c:391 [inline] seq_printf+0x195/0x240 fs/seq_file.c:406 proc_keys_show+0x792/0xd50 security/keys/proc.c:226 seq_read_iter+0x4f6/0x1240 fs/seq_file.c:230 proc_reg_read_iter+0x1fb/0x2d0 fs/proc/inode.c:300 call_read_iter include/linux/fs.h:2156 [inline] io_iter_do_read fs/io_uring.c:3501 [inline] io_read+0x33c/0xff0 fs/io_uring.c:3558 io_issue_sqe+0x800/0x7060 fs/io_uring.c:6671 __io_queue_sqe fs/io_uring.c:7018 [inline] io_queue_sqe fs/io_uring.c:7060 [inline] io_submit_sqe fs/io_uring.c:7263 [inline] io_submit_sqes+0x1bca/0x8a20 fs/io_uring.c:7369 __do_sys_io_uring_enter+0xf6e/0x1f50 fs/io_uring.c:10070 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: 0033:0x7f98666c6e99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f986503c168 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007f98667d9f60 RCX: 00007f98666c6e99 RDX: 0000000000000000 RSI: 00000000000002ff RDI: 0000000000000004 RBP: 00007f9866721031 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9866d0db1f R14: 00007f986503c300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 7: 00 8: 90 nop 9: 65 8b 15 d9 3f 9f 7e mov %gs:0x7e9f3fd9(%rip),%edx # 0x7e9f3fe9 10: 81 e2 00 00 f0 00 and $0xf00000,%edx 16: b8 01 00 00 00 mov $0x1,%eax 1b: 75 0a jne 0x27 1d: 8b 15 ca fc 2d 0c mov 0xc2dfcca(%rip),%edx # 0xc2dfced 23: 85 d2 test %edx,%edx 25: 75 01 jne 0x28 27: c3 retq 28: 55 push %rbp 29: 53 push %rbx * 2a: 65 ff 05 b8 3f 9f 7e incl %gs:0x7e9f3fb8(%rip) # 0x7e9f3fe9 <-- trapping instruction 31: e8 a3 0c e1 07 callq 0x7e10cd9 36: 48 c7 c3 00 a9 03 00 mov $0x3a900,%rbx 3d: 83 f8 07 cmp $0x7,%eax