rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=d9a/1/0x4000000000000000 softirq=12459/12467 fqs=0 (t=16263 jiffies g=9137 q=1401) rcu: rcu_preempt kthread timer wakeup didn't happen for 16262 jiffies! g9137 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=2652 rcu: rcu_preempt kthread starved for 16263 jiffies! g9137 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28944 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x907/0x26b0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_timeout+0x11d/0x250 kernel/time/timer.c:1881 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 kthread+0x38b/0x460 kernel/kthread.c:319 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: 19 Comm: ksoftirqd/1 Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_smp_processor_id+0xe/0x20 lib/smp_processor_id.c:60 Code: 74 24 20 48 c7 c7 00 0a 20 89 e8 ef 90 c0 ff e8 46 20 cf ff eb af 66 0f 1f 44 00 00 48 c7 c6 40 0a 20 89 48 c7 c7 80 0a 20 89 1d ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 fe 48 RSP: 0018:ffffc90000dc0cd0 EFLAGS: 00000006 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8152f181 RDX: fffffbfff18fa903 RSI: ffffffff89200a40 RDI: ffffffff89200a80 RBP: 1ffff920001b81a2 R08: 0000000000000000 R09: ffffffff8c7d4817 R10: fffffbfff18fa902 R11: 00000000000003d5 R12: 0000000000000001 R13: 000000000000228a R14: ffff8880167c1ae8 R15: ffff888016164580 FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fedd4f90e8 CR3: 0000000032a63000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:339 [inline] rcu_is_watching+0xe/0xc0 kernel/rcu/tree.c:1160 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5636 rcu_lock_release include/linux/rcupdate.h:272 [inline] rcu_read_unlock include/linux/rcupdate.h:720 [inline] advance_sched+0x422/0x920 net/sched/sch_taprio.c:765 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x4d7/0xb00 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x2f9/0x920 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__slab_alloc.constprop.0+0x68/0xf0 mm/slub.c:2846 Code: 5f 8a 4c 89 f9 44 89 f2 44 89 ee 48 89 ef 4d 01 e0 e8 6c f3 ff ff 49 89 c4 9c 58 f6 c4 02 75 53 48 85 db 74 01 fb 48 83 c4 08 <4c> 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 05 31 c9 ff 4c 8b 65 RSP: 0018:ffffc90000d97998 EFLAGS: 00000282 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1dbfef2 RDX: 0000000000000000 RSI: ffffffff88cb28c0 RDI: ffffffff89200ac0 RBP: ffff8880151b1000 R08: 0000000000000001 R09: ffffffff8edd9947 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888047416000 R13: 0000000000000a20 R14: 00000000ffffffff R15: ffffffff8678e0b3 slab_alloc_node mm/slub.c:2925 [inline] kmem_cache_alloc_node+0x12c/0x3e0 mm/slub.c:2995 __alloc_skb+0x153/0x280 net/core/skbuff.c:414 skb_copy+0x10c/0x2c0 net/core/skbuff.c:1585 mac80211_hwsim_tx_frame_no_nl.isra.0+0x916/0x1020 drivers/net/wireless/mac80211_hwsim.c:1565 mac80211_hwsim_tx_frame+0x1a0/0x250 drivers/net/wireless/mac80211_hwsim.c:1784 mac80211_hwsim_beacon_tx+0x3eb/0x7b0 drivers/net/wireless/mac80211_hwsim.c:1838 __iterate_interfaces+0x103/0x360 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x53/0xf0 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xb7/0x160 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x4d7/0xb00 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x340 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 run_ksoftirqd kernel/softirq.c:920 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:912 smpboot_thread_fn+0x548/0x8c0 kernel/smpboot.c:164 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 0 CPU: 0 PID: 4957 Comm: systemd-timesyn Not tainted 5.14.0-rc7-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+0x57/0x7d lib/dump_stack.c:105 nmi_cpu_backtrace.cold+0x30/0x99 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x11f/0x170 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:342 print_cpu_stall kernel/rcu/tree_stall.h:625 [inline] check_cpu_stall kernel/rcu/tree_stall.h:700 [inline] rcu_pending kernel/rcu/tree.c:3922 [inline] rcu_sched_clock_irq.cold+0x9f/0x747 kernel/rcu/tree.c:2641 update_process_times+0x13b/0x1c0 kernel/time/timer.c:1785 tick_sched_handle+0x6f/0x130 kernel/time/tick-sched.c:226 tick_sched_timer+0x132/0x210 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x18a/0xb00 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x2f9/0x920 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 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+0x22e/0x9d0 kernel/smp.c:967 Code: 38 d0 7c 08 84 d2 0f 85 2b 05 00 00 8b 43 08 a8 01 74 2e 48 89 ca 49 89 cf 48 c1 ea 03 41 83 e7 07 4c 01 e2 41 83 c7 03 f3 90 <0f> b6 02 41 38 c7 7c 08 84 c0 0f 85 d4 04 00 00 8b 43 08 a8 01 75 RSP: 0018:ffffc900015efad0 EFLAGS: 00000202 RAX: 0000000000000011 RBX: ffff8880b9f39ba0 RCX: ffff8880b9f39ba8 RDX: ffffed10173e7375 RSI: ffff8880b9e36b08 RDI: ffffffff8a5fd888 RBP: ffff8880b9e36b00 R08: 0000000000000001 R09: 0000000000000001 R10: ffffed10173c4c80 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880b9e36b08 R14: ffffed10173c6d60 R15: 0000000000000003 on_each_cpu_cond_mask+0x3f/0x70 kernel/smp.c:1133 on_each_cpu include/linux/smp.h:71 [inline] clock_was_set+0x1c/0x30 kernel/time/hrtimer.c:889 timekeeping_inject_offset+0x363/0x540 kernel/time/timekeeping.c:1375 do_adjtimex+0x1ad/0x730 kernel/time/timekeeping.c:2406 do_clock_adjtime kernel/time/posix-timers.c:1109 [inline] __do_sys_clock_adjtime+0x11a/0x1f0 kernel/time/posix-timers.c:1121 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: 0033:0x7f0ccf94c1b7 Code: 73 01 c3 48 8b 0d e1 fc 2a 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 31 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b1 fc 2a 00 f7 d8 64 89 01 48 RSP: 002b:00007ffee8669d08 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 000055bc0571d630 RCX: 00007f0ccf94c1b7 RDX: fffffffffffffff9 RSI: 00007ffee8669dd0 RDI: 0000000000000000 RBP: 00007ffee8669dd0 R08: 0000000000000020 R09: 000000000000000d R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00007ffee8669ec0 R14: 0000000000000002 R15: 0000000000000001 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 5.14.0-rc7-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:1207 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x21/0x150 kernel/rcu/tree.c:1199 Code: e9 4b fe ff ff 0f 1f 40 00 65 8b 15 a9 5d a9 7e 81 e2 00 00 f0 00 b8 01 00 00 00 75 0a 8b 15 96 b6 24 0b 85 d2 75 01 c3 55 53 <65> ff 05 88 5d a9 7e e8 13 fd 0a 07 48 c7 c3 80 68 03 00 83 f8 07 RSP: 0018:ffffc90000dc0e10 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff8880167c1b40 RCX: ffffffff815c18ba RDX: 0000000000000001 RSI: ffffffff89200a40 RDI: ffff8880b9f369c8 RBP: ffff8880b9f26600 R08: 0000000000000000 R09: ffffffff8c7d4817 R10: fffffbfff18fa902 R11: 00000000000003d5 R12: 0000000000000001 R13: ffff8880b9f26648 R14: 0000000000000001 R15: ffff8880b9f26400 FS: 0000000000000000(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fedd4f90e8 CR3: 0000000032a63000 CR4: 00000000001506e0 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_hrtimer_cancel include/trace/events/timer.h:290 [inline] debug_deactivate kernel/time/hrtimer.c:482 [inline] __run_hrtimer kernel/time/hrtimer.c:1505 [inline] __hrtimer_run_queues+0x831/0xb00 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x2f9/0x920 kernel/time/hrtimer.c:1663 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__slab_alloc.constprop.0+0x68/0xf0 mm/slub.c:2846 Code: 5f 8a 4c 89 f9 44 89 f2 44 89 ee 48 89 ef 4d 01 e0 e8 6c f3 ff ff 49 89 c4 9c 58 f6 c4 02 75 53 48 85 db 74 01 fb 48 83 c4 08 <4c> 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 05 31 c9 ff 4c 8b 65 RSP: 0018:ffffc90000d97998 EFLAGS: 00000282 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1dbfef2 RDX: 0000000000000000 RSI: ffffffff88cb28c0 RDI: ffffffff89200ac0 RBP: ffff8880151b1000 R08: 0000000000000001 R09: ffffffff8edd9947 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888047416000 R13: 0000000000000a20 R14: 00000000ffffffff R15: ffffffff8678e0b3 slab_alloc_node mm/slub.c:2925 [inline] kmem_cache_alloc_node+0x12c/0x3e0 mm/slub.c:2995 __alloc_skb+0x153/0x280 net/core/skbuff.c:414 skb_copy+0x10c/0x2c0 net/core/skbuff.c:1585 mac80211_hwsim_tx_frame_no_nl.isra.0+0x916/0x1020 drivers/net/wireless/mac80211_hwsim.c:1565 mac80211_hwsim_tx_frame+0x1a0/0x250 drivers/net/wireless/mac80211_hwsim.c:1784 mac80211_hwsim_beacon_tx+0x3eb/0x7b0 drivers/net/wireless/mac80211_hwsim.c:1838 __iterate_interfaces+0x103/0x360 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x53/0xf0 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xb7/0x160 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x4d7/0xb00 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x176/0x340 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 run_ksoftirqd kernel/softirq.c:920 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:912 smpboot_thread_fn+0x548/0x8c0 kernel/smpboot.c:164 kthread+0x38b/0x460 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 24 20 and $0x20,%al 2: 48 c7 c7 00 0a 20 89 mov $0xffffffff89200a00,%rdi 9: e8 ef 90 c0 ff callq 0xffc090fd e: e8 46 20 cf ff callq 0xffcf2059 13: eb af jmp 0xffffffc4 15: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 1b: 48 c7 c6 40 0a 20 89 mov $0xffffffff89200a40,%rsi 22: 48 c7 c7 80 0a 20 89 mov $0xffffffff89200a80,%rdi * 29: e9 1d ff ff ff jmpq 0xffffff4b <-- trapping instruction 2e: 66 66 2e 0f 1f 84 00 data16 nopw %cs:0x0(%rax,%rax,1) 35: 00 00 00 00 39: 66 90 xchg %ax,%ax 3b: 48 89 fe mov %rdi,%rsi 3e: 48 rex.W