rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=176781, q=379) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295054111-4295043609), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g176781 f0x2 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:28896 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x979/0xce0 kernel/sched/core.c:4527 watchdog: BUG: soft lockup - CPU#1 stuck for 123s! [syz-executor.2:23417] Modules linked in: irq event stamp: 51090 hardirqs last enabled at (51089): [] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 hardirqs last disabled at (51090): [] irqentry_enter+0x25/0x40 kernel/entry/common.c:319 softirqs last enabled at (1682): [] asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 softirqs last disabled at (1577): [] asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 CPU: 1 PID: 23417 Comm: syz-executor.2 Not tainted 5.9.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:csd_lock_wait kernel/smp.c:108 [inline] RIP: 0010:smp_call_function_single+0x302/0x450 kernel/smp.c:382 Code: 2f 44 89 ee 83 e6 01 31 ff e8 da 08 0b 00 41 83 e5 01 75 14 e8 bf 04 0b 00 eb 45 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f3 90 <42> 0f b6 04 23 84 c0 75 0d 41 f6 07 01 74 22 e8 9a 04 0b 00 eb e8 RSP: 0018:ffffc90018617da0 EFLAGS: 00000293 RAX: ffffffff8169f386 RBX: 1ffff920030c2fb9 RCX: ffff88800e0c4380 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90018617e38 R08: ffffffff8169f356 R09: ffffed1015d06d11 R10: ffffed1015d06d11 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000001 R14: 0000000000000000 R15: ffffc90018617dc8 FS: 00007fd6aee90700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020010038 CR3: 00000000966a3000 CR4: 00000000001526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: smp_call_function_many kernel/smp.c:577 [inline] smp_call_function kernel/smp.c:599 [inline] on_each_cpu+0x4d/0x1f0 kernel/smp.c:698 clock_was_set+0x18/0x20 kernel/time/hrtimer.c:876 do_settimeofday64+0x477/0x5b0 kernel/time/timekeeping.c:1260 __do_sys_clock_settime kernel/time/posix-timers.c:1079 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1067 [inline] __x64_sys_clock_settime+0x196/0x1c0 kernel/time/posix-timers.c:1067 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd6aee8fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 0000000000001f00 RCX: 000000000045d5b9 RDX: 0000000000000000 RSI: 0000000020000400 RDI: 0000000000000000 RBP: 000000000118cf78 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c R13: 00007fff833b92cf R14: 00007fd6aee909c0 R15: 000000000118cf4c Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1 Comm: systemd Not tainted 5.9.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:196 Code: 00 00 0f 0b 66 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 68 1b 1a 08 48 89 de 5b e9 77 6e 3f 00 cc cc cc cc cc cc cc 48 8b 04 24 <65> 48 8b 0c 25 00 fe 01 00 65 8b 15 d8 05 8d 7e f7 c2 00 01 ff 00 RSP: 0000:ffffc90000c7fcd0 EFLAGS: 00000093 RAX: ffffffff8165a194 RBX: 0000000000000000 RCX: ffff8880a99d4040 RDX: ffff8880a99d4040 RSI: 0000000000000000 RDI: 000000000000003f RBP: 1bc16d674ecbcd3b R08: ffffffff8165a186 R09: fffffbfff17426c2 R10: fffffbfff17426c2 R11: 0000000000000000 R12: ffff888086b04340 R13: ffff8880ae8276d8 R14: ffff888086b04340 R15: ffff8880ae8276c8 FS: 00007f4a33fc1500(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560145917008 CR3: 0000000099bc7000 CR4: 00000000001526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cpu_max_bits_warn include/linux/cpumask.h:137 [inline] cpumask_check include/linux/cpumask.h:144 [inline] cpumask_test_cpu include/linux/cpumask.h:367 [inline] trace_hrtimer_cancel+0x174/0x2b0 include/trace/events/timer.h:290 debug_deactivate kernel/time/hrtimer.c:487 [inline] __run_hrtimer kernel/time/hrtimer.c:1492 [inline] __hrtimer_run_queues+0x291/0x930 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0xd0/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0033:0x5601449aa74c Code: ff 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 48 85 ff 74 2b 83 7f 08 05 75 15 48 63 97 b0 07 00 00 48 8d 05 57 05 05 00 8b 04 90 0f 1f 00 8b 04 25 b0 07 00 00 0f 0b 0f 1f 80 00 00 00 00 48 8d RSP: 002b:00007ffda2682928 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00005601459162c0 RCX: 00000000000000d0 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 00005601457d4b70 RBP: 00005601449f94f8 R08: 0000000000000000 R09: 00005601459164c0 R10: 000000000000003c R11: 00007f4a33da6140 R12: 000056014586b0c0 R13: 00007ffda2682940 R14: 00007ffda2682938 R15: 00005601457cd9a0