rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (4461 ticks this GP) idle=a5a/1/0x4000000000000000 softirq=11087/11087 fqs=241 (t=10501 jiffies g=8613 q=73) rcu: rcu_preempt kthread starved for 3113 jiffies! g8613 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:29176 pid: 11 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3779 [inline] __schedule+0x893/0x2130 kernel/sched/core.c:4528 schedule+0xcf/0x270 kernel/sched/core.c:4606 schedule_timeout+0x148/0x250 kernel/time/timer.c:1871 rcu_gp_fqs_loop kernel/rcu/tree.c:1925 [inline] rcu_gp_kthread+0xb4c/0x1c90 kernel/rcu/tree.c:2099 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 NMI backtrace for cpu 1 CPU: 1 PID: 8858 Comm: syz-executor864 Not tainted 5.10.0-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:77 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 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+0x1e3/0x21e kernel/rcu/tree_stall.h:331 print_cpu_stall kernel/rcu/tree_stall.h:563 [inline] check_cpu_stall kernel/rcu/tree_stall.h:637 [inline] rcu_pending kernel/rcu/tree.c:3694 [inline] rcu_sched_clock_irq.cold+0x472/0xee8 kernel/rcu/tree.c:2567 update_process_times+0x77/0xd0 kernel/time/timer.c:1709 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x1ce/0xea0 kernel/time/hrtimer.c:1583 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1097 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline] sysvec_apic_timer_interrupt+0x48/0x100 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:rcu_read_lock_sched_held+0x0/0x70 kernel/rcu/update.c:118 Code: 41 5c 49 c1 ec 09 49 83 f4 01 41 83 e4 01 44 89 e0 41 5c c3 45 31 e4 44 89 e0 41 5c c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 <41> 54 41 bc 01 00 00 00 e8 03 7b 89 07 85 c0 75 06 44 89 e0 41 5c RSP: 0018:ffffc90000d90aa8 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000082a20 RCX: 0000000000000400 RDX: 0000000000000200 RSI: ffff88802364e000 RDI: ffffffff86ecd587 RBP: 0000000000082a20 R08: 0000000000082a20 R09: 00000000ffffffff R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000200 R13: 00000000ffffffff R14: ffff888010041280 R15: ffff88802364e000 trace_kmalloc_node include/trace/events/kmem.h:100 [inline] trace_kmalloc_node+0xc1/0xf0 include/trace/events/kmem.h:100 __kmalloc_node_track_caller+0x21a/0x3e0 mm/slub.c:4498 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0xae/0x550 net/core/skbuff.c:210 skb_copy+0x137/0x2f0 net/core/skbuff.c:1507 mac80211_hwsim_tx_frame_no_nl.isra.0+0xb17/0x1330 drivers/net/wireless/mac80211_hwsim.c:1493 mac80211_hwsim_tx_frame+0x14f/0x1e0 drivers/net/wireless/mac80211_hwsim.c:1705 mac80211_hwsim_beacon_tx+0x4ba/0x910 drivers/net/wireless/mac80211_hwsim.c:1759 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:792 ieee80211_iterate_active_interfaces_atomic+0x8d/0x170 net/mac80211/util.c:828 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1782 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x693/0xea0 kernel/time/hrtimer.c:1583 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1600 __do_softirq+0x2a0/0x9f6 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x132/0x200 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:unwind_next_frame+0x99f/0x1f90 arch/x86/kernel/unwind_orc.c:470 Code: 40 0f 95 c7 41 84 fb 0f 85 17 13 00 00 83 e0 07 40 38 c6 40 0f 9e c7 40 84 f6 0f 95 c0 40 84 c7 0f 85 fe 12 00 00 49 0f bf 00 <48> 01 d0 48 89 44 24 60 e9 1c fd ff ff 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc9000267f418 EFLAGS: 00000246 RAX: 0000000000000050 RBX: 1ffff920004cfe8b RCX: ffffffff8d6c9043 RDX: ffffc9000267f9e8 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8d6c903e R09: ffffffff8d6c9042 R10: 0000000000082081 R11: 0000000000000001 R12: ffffc9000267f538 R13: ffffc9000267f525 R14: ffffc9000267f540 R15: ffffc9000267f4f0 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3142 [inline] kmem_cache_free+0x82/0x350 mm/slub.c:3158 pgtable_pte_page_dtor include/linux/mm.h:2212 [inline] ___pte_free_tlb+0x19/0x100 arch/x86/mm/pgtable.c:55 __pte_free_tlb arch/x86/include/asm/pgalloc.h:61 [inline] free_pte_range mm/memory.c:220 [inline] free_pmd_range mm/memory.c:238 [inline] free_pud_range mm/memory.c:272 [inline] free_p4d_range mm/memory.c:306 [inline] free_pgd_range+0x498/0xc00 mm/memory.c:386 free_pgtables+0x230/0x2f0 mm/memory.c:418 exit_mmap+0x2c0/0x530 mm/mmap.c:3221 __mmput+0x122/0x470 kernel/fork.c:1079 mmput+0x53/0x60 kernel/fork.c:1100 exit_mm kernel/exit.c:486 [inline] do_exit+0xa72/0x29b0 kernel/exit.c:796 do_group_exit+0x125/0x310 kernel/exit.c:906 get_signal+0x42a/0x1f10 kernel/signal.c:2758 arch_do_signal+0x82/0x2390 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:161 [inline] exit_to_user_mode_prepare+0x100/0x1a0 kernel/entry/common.c:191 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:266 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x4488e9 Code: Unable to access opcode bytes at RIP 0x4488bf. RSP: 002b:00007f8a0a2f3cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00000000006ddc58 RCX: 00000000004488e9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006ddc58 RBP: 00000000006ddc50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006ddc5c R13: 00007ffcdde4c72f R14: 00007f8a0a2f49c0 R15: 00000000006ddc5c