rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (3 ticks this GP) idle=6cfc/1/0x4000000000000000 softirq=45505/45505 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=32033, q=347 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5822 Comm: syz-executor Not tainted 6.15.0-next-20250530-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 84 24 fa 0b 48 89 de 5b e9 73 bc 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 d0 9c 92 65 8b 15 68 70 dc 10 81 e2 00 01 ff 00 RSP: 0018:ffffc90000a08d10 EFLAGS: 00000002 RAX: ffffffff81aea839 RBX: 0000000000000001 RCX: 8927338f7f1dfc00 RDX: ffff888078870000 RSI: ffffffff8be29c60 RDI: ffffffff8be29c20 RBP: ffffc90000a08e90 R08: ffffffff8fa127f7 R09: 1ffffffff1f424fe R10: dffffc0000000000 R11: fffffbfff1f424ff R12: ffff888079f3e340 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8727c40 FS: 0000000000000000(0000) GS:ffff888125d53000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000057f000 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hrtimer_cancel include/trace/events/timer.h:317 [inline] debug_deactivate+0x89/0x200 kernel/time/hrtimer.c:491 __run_hrtimer kernel/time/hrtimer.c:1729 [inline] __hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 4b 7f 5f f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 73 6a 28 f6 65 8b 05 5c 63 34 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc9000442ef00 EFLAGS: 00000206 RAX: 8927338f7f1dfc00 RBX: 0000000000000a06 RCX: 8927338f7f1dfc00 RDX: 0000000000000007 RSI: ffffffff8d98278e RDI: 0000000000000001 RBP: ffffc9000442ef90 R08: ffffffff8fa127f7 R09: 1ffffffff1f424fe R10: dffffc0000000000 R11: fffffbfff1f424ff R12: dffffc0000000000 R13: ffffc9000442f1f8 R14: ffff88801cea8098 R15: 1ffff92000885de0 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1506 [inline] folios_put_refs+0x4ef/0x640 mm/swap.c:984 free_pages_and_swap_cache+0x277/0x520 mm/swap_state.c:264 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404 zap_pte_range mm/memory.c:1774 [inline] zap_pmd_range mm/memory.c:1827 [inline] zap_pud_range mm/memory.c:1856 [inline] zap_p4d_range mm/memory.c:1877 [inline] unmap_page_range+0x38fd/0x41c0 mm/memory.c:1898 unmap_single_vma mm/memory.c:1941 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1985 exit_mmap+0x248/0xb50 mm/mmap.c:1284 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x640/0x22e0 kernel/exit.c:943 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbc24d8d3e0 Code: Unable to access opcode bytes at 0x7fbc24d8d3b6. RSP: 002b:00007ffd23853218 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: 00000000000004a0 RBX: 000000012e320f80 RCX: 00007fbc24d8d3e0 RDX: 00000000000004a0 RSI: 00007fbc1f9ffb60 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000007 R09: 00000000003ffde8 R10: a4cf9abc5ddbd79b R11: 0000000000000202 R12: 00000000000004a0 R13: 0000555577a5a210 R14: 00007ffd238536e0 R15: 00007fbc1f9ffb60 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g32033 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=20999 rcu: rcu_preempt kthread starved for 10502 jiffies! g32033 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26824 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245