rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=047/1/0x4000000000000000 softirq=147912/147912 fqs=0 (t=10501 jiffies g=318837 q=9323) rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g318837 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=103395 rcu: rcu_preempt kthread starved for 10504 jiffies! g318837 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28696 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: NMI backtrace for cpu 0 CPU: 0 PID: 9000 Comm: syz-executor.2 Not tainted 5.15.0-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:106 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_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481 print_cpu_stall kernel/rcu/tree_stall.h:625 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3880 [inline] rcu_sched_clock_irq.cold+0x98/0x746 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+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:finish_task_switch.isra.0+0x23c/0xa50 kernel/sched/core.c:4814 Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 f3 66 e7 07 e8 fe 2c 2c 00 fb 65 48 8b 1c 25 40 f0 01 00 <48> 8d bb 18 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc900243377c0 EFLAGS: 00000206 RAX: 000000000000422b RBX: ffff8881766f3900 RCX: 1ffffffff1adc3a9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90024337800 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817c37a8 R11: 0000000000000000 R12: ffff8880b9c31a40 R13: ffff8881733d0000 R14: 0000000000000000 R15: ffff8880b9c31a58 context_switch kernel/sched/core.c:4943 [inline] __schedule+0x948/0x26f0 kernel/sched/core.c:6287 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6687 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:__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:ffffc900243379b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88818f9eab50 RCX: 0000000000000000 RDX: ffff8881766f3900 RSI: ffffffff81b5aacb RDI: 0000000000000003 RBP: 0000000000000168 R08: 00000000000001fe R09: 0000000000000000 R10: ffffffff81b5aaf2 R11: 0000000000000000 R12: 00000000000001fe R13: ffff88818f9ea010 R14: dffffc0000000000 R15: ffffc90024337ab0 free_pages_and_swap_cache+0x3b/0x90 mm/swap_state.c:319 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:242 [inline] tlb_flush_mmu mm/mmu_gather.c:249 [inline] tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:340 exit_mmap+0x1ea/0x630 mm/mmap.c:3173 __mmput+0x122/0x4b0 kernel/fork.c:1115 mmput+0x58/0x60 kernel/fork.c:1136 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:00007faa69e33218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000056bf88 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf88 RBP: 000000000056bf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf8c R13: 00007ffed7d2c5ff R14: 00007faa69e33300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 9000 Comm: syz-executor.2 Not tainted 5.15.0-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:106 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+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:finish_task_switch.isra.0+0x23c/0xa50 kernel/sched/core.c:4814 Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 f3 66 e7 07 e8 fe 2c 2c 00 fb 65 48 8b 1c 25 40 f0 01 00 <48> 8d bb 18 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc900243377c0 EFLAGS: 00000206 RAX: 000000000000422b RBX: ffff8881766f3900 RCX: 1ffffffff1adc3a9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90024337800 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817c37a8 R11: 0000000000000000 R12: ffff8880b9c31a40 R13: ffff8881733d0000 R14: 0000000000000000 R15: ffff8880b9c31a58 context_switch kernel/sched/core.c:4943 [inline] __schedule+0x948/0x26f0 kernel/sched/core.c:6287 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6687 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:__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:ffffc900243379b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88818f9eab50 RCX: 0000000000000000 RDX: ffff8881766f3900 RSI: ffffffff81b5aacb RDI: 0000000000000003 RBP: 0000000000000168 R08: 00000000000001fe R09: 0000000000000000 R10: ffffffff81b5aaf2 R11: 0000000000000000 R12: 00000000000001fe R13: ffff88818f9ea010 R14: dffffc0000000000 R15: ffffc90024337ab0 free_pages_and_swap_cache+0x3b/0x90 mm/swap_state.c:319 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:242 [inline] tlb_flush_mmu mm/mmu_gather.c:249 [inline] tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:340 exit_mmap+0x1ea/0x630 mm/mmap.c:3173 __mmput+0x122/0x4b0 kernel/fork.c:1115 mmput+0x58/0x60 kernel/fork.c:1136 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:00007faa69e33218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000056bf88 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf88 RBP: 000000000056bf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf8c R13: 00007ffed7d2c5ff R14: 00007faa69e33300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 8b 3a mov (%rdx),%edi 2: 4c 89 e7 mov %r12,%rdi 5: 48 c7 02 00 00 00 00 movq $0x0,(%rdx) c: ff d1 callq *%rcx e: 4d 85 ff test %r15,%r15 11: 75 bf jne 0xffffffd2 13: 4c 89 e7 mov %r12,%rdi 16: e8 f3 66 e7 07 callq 0x7e7670e 1b: e8 fe 2c 2c 00 callq 0x2c2d1e 20: fb sti 21: 65 48 8b 1c 25 40 f0 mov %gs:0x1f040,%rbx 28: 01 00 * 2a: 48 8d bb 18 15 00 00 lea 0x1518(%rbx),%rdi <-- trapping instruction 31: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 38: fc ff df 3b: 48 89 fa mov %rdi,%rdx 3e: 48 rex.W 3f: c1 .byte 0xc1