rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10447 ticks this GP) idle=f8f/1/0x4000000000000000 softirq=26794/26801 fqs=120 (t=10500 jiffies g=34745 q=661) rcu: rcu_preempt kthread starved for 689 jiffies! g34745 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:28736 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x800 kernel/rcu/tree.c:1957 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2130 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: 19304 Comm: syz-executor.1 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:110 Code: c7 40 f7 ee 8e e8 28 3b 8a 00 eb b0 66 0f 1f 44 00 00 be 01 00 00 00 e9 e6 1e 2d 00 cc cc cc cc cc cc 89 ff 89 b7 00 c0 5f ff 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb 48 RSP: 0018:ffffc90000dc0470 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff8b337a60 RCX: 0000000000000020 RDX: 1ffffffff1666f4e RSI: 00000000000000c6 RDI: 0000000000000380 RBP: ffff8880b9d1f300 R08: 000000000000003f R09: ffffffff8d6ea4d7 R10: ffffffff8168f927 R11: 0000000000000000 R12: 00000000000000c6 R13: 0000000000000020 R14: 0000000000000000 R15: ffff8880b9d223c0 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c017808020 CR3: 000000001e50f000 CR4: 0000000000350ee0 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x4d/0x80 arch/x86/kernel/apic/apic.c:469 clockevents_program_event+0x254/0x370 kernel/time/clockevents.c:334 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36e/0x790 kernel/time/hrtimer.c:1824 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:unwind_get_return_address arch/x86/kernel/unwind_orc.c:318 [inline] RIP: 0010:unwind_get_return_address+0x66/0x90 arch/x86/kernel/unwind_orc.c:313 Code: 89 ea 48 c1 ea 03 80 3c 02 00 75 32 48 8b 7b 48 e8 2f 69 19 00 85 c0 74 d3 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 <80> 3c 02 00 75 18 48 8b 43 48 5b 5d c3 e8 68 4f 89 00 eb a8 48 89 RSP: 0018:ffffc90000dc0670 EFLAGS: 00000212 RAX: dffffc0000000000 RBX: ffffc90000dc0688 RCX: 0000000000000000 RDX: 1ffff920001b80da RSI: ffffc90000dc0fe0 RDI: ffffffff814675a5 RBP: ffffc90000dc06d0 R08: ffffffff8de9a3c6 R09: 0000000000000001 R10: fffff520001b80dc R11: 0000000000086089 R12: ffffc90000dc0740 R13: 0000000000000000 R14: ffff888025765580 R15: 0000000000000000 arch_stack_walk+0x93/0xe0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1628 [inline] slab_free_freelist_hook+0xe3/0x250 mm/slub.c:1653 slab_free mm/slub.c:3213 [inline] kfree+0xe4/0x540 mm/slub.c:4267 skb_free_head net/core/skbuff.c:654 [inline] skb_release_data+0x65a/0x790 net/core/skbuff.c:676 skb_release_all net/core/skbuff.c:741 [inline] __kfree_skb net/core/skbuff.c:755 [inline] kfree_skb net/core/skbuff.c:773 [inline] kfree_skb+0x133/0x3f0 net/core/skbuff.c:767 __netif_receive_skb_core+0x54f/0x3640 net/core/dev.c:5410 __netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5434 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5550 process_backlog+0x2a5/0x6c0 net/core/dev.c:6427 __napi_poll+0xaf/0x440 net/core/dev.c:6982 napi_poll net/core/dev.c:7049 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7136 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 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:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:197 Code: 81 e1 00 01 00 00 65 48 8b 14 25 40 f0 01 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 3c 15 00 00 85 c0 74 2b 8b 82 18 15 00 00 <83> f8 02 75 20 48 8b 8a 20 15 00 00 8b 92 1c 15 00 00 48 8b 01 48 RSP: 0018:ffffc9000307f770 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffea0001d00340 RCX: 0000000000000000 RDX: ffff888025765580 RSI: ffffffff819d1bd2 RDI: 0000000000000003 RBP: ffffea0001d00340 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff819d1bc4 R11: 0000000000000000 R12: 0000000000000000 R13: ffffea0001d00348 R14: 0000000000000000 R15: 00007f7b05290000 PagePoisoned include/linux/page-flags.h:207 [inline] PageDirty include/linux/page-flags.h:337 [inline] set_page_dirty+0x312/0x6b0 mm/page-writeback.c:2611 zap_pte_range mm/memory.c:1355 [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+0x1d5d/0x2a10 mm/memory.c:1552 unmap_single_vma+0x198/0x310 mm/memory.c:1597 unmap_vmas+0x16d/0x2f0 mm/memory.c:1629 exit_mmap+0x1d0/0x620 mm/mmap.c:3171 __mmput+0x122/0x4b0 kernel/fork.c:1114 mmput+0x58/0x60 kernel/fork.c:1135 exit_mm kernel/exit.c:501 [inline] do_exit+0xabc/0x2a30 kernel/exit.c:812 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2160 kernel/signal.c:2868 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: 0033:0x4665f9 Code: Unable to access opcode bytes at RIP 0x4665cf. RSP: 002b:00007f7b02a1a188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: fffffffffffffdfe RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcc4 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffc05c1d37f R14: 00007f7b02a1a300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 19325 Comm: syz-executor.0 Not tainted 5.14.0-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+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2599 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:1421 __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:unwind_next_frame+0x150d/0x1ce0 arch/x86/kernel/unwind_orc.c:604 Code: d7 f9 ff ff 48 39 e8 0f 86 ce f9 ff ff 48 8d 55 08 48 39 d0 0f 93 c1 49 39 d4 0f 92 c0 84 c1 0f 84 b6 f9 ff ff 48 39 6c 24 18 <0f> 82 ab f9 ff ff 49 8d 7e 28 48 b8 00 00 00 00 00 fc ff df 48 89 RSP: 0018:ffffc90000007740 EFLAGS: 00000287 RAX: ffffc90000008001 RBX: 1ffff92000000ef0 RCX: 1ffff92000000f01 RDX: ffffc90000007f78 RSI: ffffc90000007f40 RDI: ffffc90000007828 RBP: ffffc90000007f70 R08: ffffffff8ded2e1a R09: 0000000000000001 R10: fffff52000000f0e R11: 0000000000086089 R12: ffffc90000000000 R13: ffffc9000000784d R14: ffffc90000007818 R15: ffffc9000000784c 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:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1628 [inline] slab_free_freelist_hook+0xe3/0x250 mm/slub.c:1653 slab_free mm/slub.c:3213 [inline] kfree+0xe4/0x540 mm/slub.c:4267 skb_free_head net/core/skbuff.c:654 [inline] skb_release_data+0x65a/0x790 net/core/skbuff.c:676 skb_release_all net/core/skbuff.c:741 [inline] __kfree_skb net/core/skbuff.c:755 [inline] consume_skb net/core/skbuff.c:911 [inline] consume_skb+0xc2/0x160 net/core/skbuff.c:905 mac80211_hwsim_tx_frame+0x1f6/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1785 mac80211_hwsim_beacon_tx+0x49b/0x930 drivers/net/wireless/mac80211_hwsim.c:1838 __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:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 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:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__orc_find+0x8f/0xf0 arch/x86/kernel/unwind_orc.c:49 Code: d8 48 c1 e8 03 42 0f b6 14 38 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 48 48 63 03 48 01 d8 48 39 c1 73 b0 4c 8d 63 fc <49> 39 ec 73 b3 4d 29 ee 49 c1 fe 02 4b 8d 04 76 48 8d 04 46 48 83 RSP: 0018:ffffc900038475f8 EFLAGS: 00000287 RAX: ffffffff842f6491 RBX: ffffffff8da1498c RCX: ffffffff842f6443 RDX: 0000000000000000 RSI: ffffffff8e21bc78 RDI: ffffffff8da14980 RBP: ffffffff8da14980 R08: 0000000000000000 R09: ffffffff8e21bc78 R10: fffff52000708eee R11: 0000000000086089 R12: ffffffff8da14988 R13: ffffffff8da14980 R14: ffffffff8da14980 R15: dffffc0000000000 orc_find arch/x86/kernel/unwind_orc.c:173 [inline] unwind_next_frame+0x32a/0x1ce0 arch/x86/kernel/unwind_orc.c:443 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121 save_stack+0x151/0x1e0 mm/page_owner.c:119 __reset_page_owner+0x5d/0x170 mm/page_owner.c:140 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1346 [inline] free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397 free_unref_page_prepare mm/page_alloc.c:3332 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3411 __vunmap+0x783/0xb70 mm/vmalloc.c:2609 __vfree+0x3c/0xd0 mm/vmalloc.c:2657 vfree+0x5a/0x90 mm/vmalloc.c:2688 n_tty_close+0xcf/0x1e0 drivers/tty/n_tty.c:1828 tty_ldisc_close+0x110/0x190 drivers/tty/tty_ldisc.c:474 tty_ldisc_kill+0x94/0x150 drivers/tty/tty_ldisc.c:629 tty_ldisc_release+0x154/0x2a0 drivers/tty/tty_ldisc.c:803 tty_release_struct+0x20/0xe0 drivers/tty/tty_io.c:1706 tty_release+0xc70/0x1200 drivers/tty/tty_io.c:1878 __fput+0x288/0x9f0 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 get_signal+0x1b35/0x2160 kernel/signal.c:2641 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: 0033:0x4665f9 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:00007f8939688188 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: fffffffffffffdfe RBX: 000000000056bf80 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000040 RBP: 00000000004bfcc4 R08: 0000000020000200 R09: 0000000000000000 R10: 0000000020000140 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffde3b9001f R14: 00007f8939688300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: c7 40 f7 ee 8e e8 28 movl $0x28e88eee,-0x9(%rax) 7: 3b 8a 00 eb b0 66 cmp 0x66b0eb00(%rdx),%ecx d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 12: be 01 00 00 00 mov $0x1,%esi 17: e9 e6 1e 2d 00 jmpq 0x2d1f02 1c: cc int3 1d: cc int3 1e: cc int3 1f: cc int3 20: cc int3 21: cc int3 22: 89 ff mov %edi,%edi 24: 89 b7 00 c0 5f ff mov %esi,-0xa04000(%rdi) * 2a: c3 retq <-- trapping instruction 2b: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 32: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 39: fc ff df 3c: 53 push %rbx 3d: 89 fb mov %edi,%ebx 3f: 48 rex.W