rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10494 ticks this GP) idle=196/1/0x4000000000000000 softirq=21100/21110 fqs=180 (t=10501 jiffies g=24033 q=1593) rcu: rcu_preempt kthread starved for 858 jiffies! g24033 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:29280 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4683 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5940 schedule+0xd3/0x270 kernel/sched/core.c:6019 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1878 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 kthread+0x3e5/0x4d0 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: 15613 Comm: syz-executor.3 Tainted: G W 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197 Code: 01 f0 4d 89 03 e9 63 fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 <65> 8b 05 09 67 8c 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc90000dc0cc8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000100 RDX: ffff88806c4f1c40 RSI: ffffffff8165e1cf RDI: 0000000000000003 RBP: 000000000000caea R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8165e1c5 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8b99ae08 R15: ffff88806ca47050 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd206dcfb8 CR3: 0000000064057000 CR4: 0000000000350ee0 Call Trace: __seqprop_raw_spinlock_sequence include/linux/seqlock.h:276 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get_with_offset+0x1f5/0x500 kernel/time/timekeeping.c:872 ktime_get_real include/linux/timekeeping.h:79 [inline] mac80211_hwsim_get_tsf_raw drivers/net/wireless/mac80211_hwsim.c:977 [inline] mac80211_hwsim_beacon_tx+0x2e6/0x930 drivers/net/wireless/mac80211_hwsim.c:1823 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x70/0x180 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__kasan_check_read+0x4/0x10 mm/kasan/shadow.c:31 Code: 2c 07 48 85 db 0f 85 71 cf 2d 07 48 83 c4 60 5b 5d 41 5c 41 5d c3 c3 e9 71 d0 2d 07 cc cc cc cc cc cc cc cc cc cc 48 8b 0c 24 <89> f6 31 d2 e9 03 f9 ff ff 0f 1f 00 48 8b 0c 24 89 f6 ba 01 00 00 RSP: 0018:ffffc900031d7638 EFLAGS: 00000256 RAX: 0000000000000000 RBX: 1ffff9200063aeca RCX: ffffffff815b0bc8 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8d6c4bd0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81af1dfc R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8b97b900 R15: 0000000000000000 instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] cpumask_test_cpu include/linux/cpumask.h:344 [inline] cpu_online include/linux/cpumask.h:895 [inline] trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0xb8/0x510 kernel/locking/lockdep.c:5596 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:687 [inline] __mod_lruvec_page_state+0xbe/0x2c0 mm/memcontrol.c:745 page_remove_file_rmap mm/rmap.c:1286 [inline] page_remove_rmap+0x71f/0x1480 mm/rmap.c:1348 zap_pte_range mm/memory.c:1362 [inline] zap_pmd_range mm/memory.c:1481 [inline] zap_pud_range mm/memory.c:1510 [inline] zap_p4d_range mm/memory.c:1531 [inline] unmap_page_range+0xed5/0x2a10 mm/memory.c:1552 unmap_single_vma+0x198/0x300 mm/memory.c:1597 unmap_vmas+0x16d/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x620 mm/mmap.c:3201 __mmput+0x122/0x470 kernel/fork.c:1101 mmput+0x58/0x60 kernel/fork.c:1122 exit_mm kernel/exit.c:501 [inline] do_exit+0xae2/0x2a60 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2808 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 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:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 Code: Unable to access opcode bytes at RIP 0x4665af. RSP: 002b:00007f46e8e24218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000056c040 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056c040 RBP: 000000000056c038 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c044 R13: 00007ffe981866af R14: 00007f46e8e24300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 15585 Comm: syz-executor.2 Tainted: G W 5.14.0-rc1-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:105 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+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+0x16d/0x200 kernel/time/timer.c:1782 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1421 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1601 hrtimer_interrupt+0x330/0xa00 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+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:ipv6_addr_equal include/net/ipv6.h:580 [inline] RIP: 0010:ipv6_chk_mcast_addr+0x158/0x8b0 net/ipv6/mcast.c:1020 Code: 9e 70 98 f9 48 85 db 0f 84 19 01 00 00 e8 90 70 98 f9 48 89 d8 48 c1 e8 03 80 3c 28 00 0f 85 73 06 00 00 41 80 3e 00 4c 8b 3b <0f> 85 59 06 00 00 48 8d 7b 08 4d 33 3c 24 48 89 f8 48 c1 e8 03 80 RSP: 0018:ffffc90000007b88 EFLAGS: 00000246 RAX: 1ffff1100574d380 RBX: ffff88802ba69c00 RCX: 0000000000000100 RDX: ffff8880186e0000 RSI: ffffffff87dd1820 RDI: 0000000000000003 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff87dd18b0 R11: 0000000000000000 R12: ffff88805a862028 R13: ffffed100b50c406 R14: ffffed100b50c405 R15: 00000000000002ff ip6_mc_input+0x30f/0xeb0 net/ipv6/ip6_input.c:503 dst_input include/net/dst.h:458 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ipv6_rcv+0x28c/0x3c0 net/ipv6/ip6_input.c:297 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5486 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5600 process_backlog+0x2a5/0x6c0 net/core/dev.c:6464 __napi_poll+0xaf/0x440 net/core/dev.c:7019 napi_poll net/core/dev.c:7086 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7173 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:preempt_schedule_irq+0x49/0x90 kernel/sched/core.c:6328 Code: 55 53 65 48 8b 1c 25 00 f0 01 00 48 89 dd 48 c1 ed 03 48 01 c5 bf 01 00 00 00 e8 12 21 24 f8 e8 6d 68 50 f8 fb bf 01 00 00 00 d2 cd ff ff 9c 58 fa f6 c4 02 75 27 bf 01 00 00 00 e8 20 10 24 RSP: 0018:ffffc9000309f678 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffff8880186e0000 RCX: 1ffffffff1ad8fdd RDX: 0000000000000000 RSI: ffffffff817bac21 RDI: 0000000000000001 RBP: ffffed10030dc000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff817bac08 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 irqentry_exit+0x31/0x80 kernel/entry/common.c:427 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:do_select+0x9b7/0x16a0 fs/select.c:553 Code: a9 ff 48 85 db 74 1e e8 67 22 a9 ff 4c 09 b4 24 80 00 00 00 48 c7 84 24 58 01 00 00 00 00 00 00 83 44 24 28 01 e8 49 22 a9 ff <8b> 5c 24 28 31 ff 89 de e8 7c 29 a9 ff 85 db 0f 85 7d 04 00 00 e8 RSP: 0018:ffffc9000309f740 EFLAGS: 00000216 RAX: 0000000000022f82 RBX: 0000000000000000 RCX: ffffc9001242b000 RDX: 0000000000040000 RSI: ffffffff81cc6667 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81cc6624 R11: 0000000000000000 R12: 0000000000000145 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 core_sys_select+0x3c2/0x9c0 fs/select.c:677 do_pselect.constprop.0+0x17b/0x1c0 fs/select.c:759 __do_sys_pselect6 fs/select.c:800 [inline] __se_sys_pselect6 fs/select.c:791 [inline] __x64_sys_pselect6+0x1c5/0x2b0 fs/select.c:791 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: 0033:0x4665d9 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:00007fe341b9d188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcb9 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007fff81649e7f R14: 00007fe341b9d300 R15: 0000000000022000