rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=83693, q=1006) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295016050-4295005547), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g83693 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:28720 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4e90 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1971 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2144 kthread+0x2e9/0x3a0 kernel/kthread.c:377 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 21427 Comm: syz-executor.0 Not tainted 5.16.0-rc6-next-20211224-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:379 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:921 [inline] RIP: 0010:trace_lock_acquire include/trace/events/lock.h:13 [inline] RIP: 0010:lock_acquire+0xa7/0x510 kernel/locking/lockdep.c:5610 Code: a8 00 00 00 31 c0 0f 1f 44 00 00 65 8b 15 d9 30 a5 7e 83 fa 07 0f 87 dc 03 00 00 89 d2 be 08 00 00 00 48 89 d0 48 89 54 24 08 <48> c1 f8 06 48 8d 3c c5 d0 31 93 8d e8 e8 2c 66 00 48 8b 54 24 08 RSP: 0018:ffffc90000006730 EFLAGS: 00000097 RAX: 0000000000000000 RBX: 1ffff92000000ce8 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8bb828e0 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff819a94b1 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8bb828e0 R15: 0000000000000000 FS: 00007fd449777700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffea8f522fc CR3: 000000009c9ba000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:694 [inline] __perf_output_begin kernel/events/ring_buffer.c:163 [inline] perf_output_begin_forward+0xb0/0xae0 kernel/events/ring_buffer.c:268 __perf_event_output kernel/events/core.c:7510 [inline] perf_event_output_forward+0xf2/0x280 kernel/events/core.c:7528 __perf_event_overflow+0x13c/0x3d0 kernel/events/core.c:9228 perf_swevent_hrtimer+0x37c/0x3f0 kernel/events/core.c:10621 __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:__is_kernel_text include/asm-generic/sections.h:192 [inline] RIP: 0010:is_kernel_text include/linux/kallsyms.h:29 [inline] RIP: 0010:core_kernel_text+0x0/0x90 kernel/extable.c:67 Code: 48 c1 fe 02 48 0f af f0 e8 0d 98 be 02 48 85 c0 74 02 5d c3 48 89 ef e8 7e af 20 00 48 85 c0 75 f1 48 89 ef 5d e9 c0 7f 37 00 <48> 81 ff 00 00 00 81 41 54 53 48 89 fb 72 09 48 81 ff c0 75 80 89 RSP: 0018:ffffc90000006f00 EFLAGS: 00000292 RAX: dffffc0000000000 RBX: ffffffff89600068 RCX: 0000000000000000 RDX: 1ffff92000000df2 RSI: ffffc900103d7f48 RDI: ffffffff89600068 RBP: ffffffff89600068 R08: ffffffff8ea78500 R09: 0000000000000001 R10: fffff52000000df4 R11: 0000000000088077 R12: ffffc90000007000 R13: 0000000000000000 R14: ffff888083548000 R15: 0000000000000820 kernel_text_address+0xd/0x80 kernel/extable.c:98 __kernel_text_address+0x9/0x30 kernel/extable.c:78 unwind_get_return_address arch/x86/kernel/unwind_orc.c:318 [inline] unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:313 arch_stack_walk+0x93/0xe0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:741 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x202/0x3a0 mm/slub.c:3243 skb_ext_maybe_cow net/core/skbuff.c:6301 [inline] skb_ext_add+0xf6/0x790 net/core/skbuff.c:6367 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:160 [inline] br_nf_forward_ip+0xdd/0x1cb0 net/bridge/br_netfilter_hooks.c:589 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:619 nf_hook+0x3d4/0x680 include/linux/netfilter.h:262 NF_HOOK include/linux/netfilter.h:305 [inline] __br_forward+0x198/0x620 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] br_flood+0x367/0x450 net/bridge/br_forward.c:240 br_handle_frame_finish+0xf66/0x1850 net/bridge/br_input.c:168 br_nf_hook_thresh+0x2a5/0x360 net/bridge/br_netfilter_hooks.c:1024 br_nf_pre_routing_finish_ipv6+0x684/0xe00 net/bridge/br_netfilter_ipv6.c:206 NF_HOOK include/linux/netfilter.h:307 [inline] br_nf_pre_routing_ipv6+0x42c/0x7b0 net/bridge/br_netfilter_ipv6.c:236 br_nf_pre_routing+0x1477/0x1ec0 net/bridge/br_netfilter_hooks.c:505 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_bridge_pre net/bridge/br_input.c:230 [inline] br_handle_frame+0x8f8/0x1180 net/bridge/br_input.c:370 __netif_receive_skb_core+0x9f7/0x3850 net/core/dev.c:5244 __netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5348 __netif_receive_skb+0x24/0x1b0 net/core/dev.c:5464 process_backlog+0x2a5/0x6c0 net/core/dev.c:5796 __napi_poll+0xaf/0x440 net/core/dev.c:6364 napi_poll net/core/dev.c:6431 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:6518 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 Code: 74 24 10 e8 8a 4d 04 f8 48 89 ef e8 42 c3 04 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 43 7d f7 f7 65 8b 05 dc db a9 76 85 c0 74 0a 5b 5d c3 e8 a0 b8 RSP: 0018:ffffc900103d7930 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1ff91c6 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffffff9071c608 R08: 0000000000000001 R09: ffffffff8ffb5977 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000008 R13: 0000000000000008 R14: dead000000000100 R15: dffffc0000000000 __debug_check_no_obj_freed lib/debugobjects.c:1002 [inline] debug_check_no_obj_freed+0x20c/0x420 lib/debugobjects.c:1023 free_pages_prepare mm/page_alloc.c:1358 [inline] free_pcp_prepare+0x2be/0xb60 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 __update_and_free_page.part.0+0x496/0x550 mm/hugetlb.c:1564 __update_and_free_page mm/hugetlb.c:1535 [inline] update_and_free_page+0xa1/0x170 mm/hugetlb.c:1620 update_and_free_pages_bulk mm/hugetlb.c:1640 [inline] return_unused_surplus_pages+0x2c6/0x400 mm/hugetlb.c:2449 hugetlb_acct_memory.part.0+0xc7/0xd0 mm/hugetlb.c:4534 hugetlb_acct_memory mm/hugetlb.c:4495 [inline] hugetlb_vm_op_close+0x4d1/0x5c0 mm/hugetlb.c:4581 remove_vma+0xac/0x170 mm/mmap.c:185 remove_vma_list mm/mmap.c:2635 [inline] __do_munmap+0x71e/0x11a0 mm/mmap.c:2893 do_munmap mm/mmap.c:2901 [inline] munmap_vma_range mm/mmap.c:604 [inline] mmap_region+0x2fd/0x1630 mm/mmap.c:1748 do_mmap+0x869/0xfb0 mm/mmap.c:1582 vm_mmap_pgoff+0x1b7/0x290 mm/util.c:519 ksys_mmap_pgoff+0x1c7/0x5a0 mm/mmap.c:1630 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: 0033:0x7fd44ae01e99 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:00007fd449777168 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fd44af14f60 RCX: 00007fd44ae01e99 RDX: 0000000000000000 RSI: 0000000000e7e000 RDI: 0000000020000000 RBP: 00007fd44ae5bff1 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000041032 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc6a19c19f R14: 00007fd449777300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: a8 00 test $0x0,%al 2: 00 00 add %al,(%rax) 4: 31 c0 xor %eax,%eax 6: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) b: 65 8b 15 d9 30 a5 7e mov %gs:0x7ea530d9(%rip),%edx # 0x7ea530eb 12: 83 fa 07 cmp $0x7,%edx 15: 0f 87 dc 03 00 00 ja 0x3f7 1b: 89 d2 mov %edx,%edx 1d: be 08 00 00 00 mov $0x8,%esi 22: 48 89 d0 mov %rdx,%rax 25: 48 89 54 24 08 mov %rdx,0x8(%rsp) * 2a: 48 c1 f8 06 sar $0x6,%rax <-- trapping instruction 2e: 48 8d 3c c5 d0 31 93 lea -0x726cce30(,%rax,8),%rdi 35: 8d 36: e8 e8 2c 66 00 callq 0x662d23 3b: 48 8b 54 24 08 mov 0x8(%rsp),%rdx