rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4377/1:b..l P4326/1:b..l (detected by 0, t=10502 jiffies, g=8097, q=122) task:kworker/1:12 state:R running task stack:23280 pid: 4326 ppid: 2 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc900032df9a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: d6b61787c18f9200 RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980 RBP: ffffc900032dfac0 R08: dffffc0000000000 R09: 1ffffffff203a818 R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffffffff8c31eaa0 R13: 1ffff9200065bf40 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] gc_worker+0x25c/0x1390 net/netfilter/nf_conntrack_core.c:1470 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 task:syz.3.20 state:R running task stack:25392 pid: 4377 ppid: 4186 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571 preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6596 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:404 [inline] filemap_map_pages+0x1054/0x13b0 mm/filemap.c:3353 do_fault_around mm/memory.c:4243 [inline] do_read_fault mm/memory.c:4258 [inline] do_fault mm/memory.c:4392 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x25bc/0x4410 mm/memory.c:4883 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x94b/0x11e0 mm/gup.c:1197 populate_vma_page_range+0x213/0x290 mm/gup.c:1529 __mm_populate+0x275/0x3b0 mm/gup.c:1638 mm_populate include/linux/mm.h:2646 [inline] vm_mmap_pgoff+0x212/0x2d0 mm/util.c:556 ksys_mmap_pgoff+0x140/0x790 mm/mmap.c:1635 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fd1aae01819 RSP: 002b:00007fd1a905b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fd1ab07afa0 RCX: 00007fd1aae01819 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fd1aae97c91 R08: ffffffffffffffff R09: 00000000a30fe000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1ab07b038 R14: 00007fd1ab07afa0 R15: 00007ffe1cd1d798 rcu: rcu_preempt kthread timer wakeup didn't happen for 10552 jiffies! g8097 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=2332 rcu: rcu_preempt kthread starved for 10553 jiffies! g8097 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:27536 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 4388 Comm: syz.1.24 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:hlock_class kernel/locking/lockdep.c:197 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4686 [inline] RIP: 0010:__lock_acquire+0x532/0x7d10 kernel/locking/lockdep.c:4962 Code: 81 e3 ff 1f 00 00 41 c1 ed 03 41 81 e5 f8 03 00 00 49 8d bd c0 40 1d 90 be 08 00 00 00 e8 c6 23 61 00 48 0f a3 1d 7e 36 c0 0e <73> 1f 48 8d 04 5b c1 e0 06 48 8d 98 80 bf b5 8f 48 ba 00 00 00 00 RSP: 0018:ffffc90002e3fae0 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 00000000000000a2 RCX: ffffffff815d0a3a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d40d0 RBP: ffffc90002e3fd30 R08: ffffffff901d40d7 R09: 1ffffffff203a81a R10: dffffc0000000000 R11: fffffbfff203a81b R12: ffff88802c40e450 R13: 0000000000000010 R14: 0000000000000000 R15: ffff88802c40e430 FS: 00007f46a45616c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000058 CR3: 0000000074c5e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 do_write_seqcount_begin_nested include/linux/seqlock.h:519 [inline] do_write_seqcount_begin include/linux/seqlock.h:545 [inline] vtime_user_enter+0x96/0x2d0 kernel/sched/cputime.c:715 __context_tracking_enter+0x60/0x90 kernel/context_tracking.c:82 user_enter_irqoff include/linux/context_tracking.h:41 [inline] __exit_to_user_mode kernel/entry/common.c:136 [inline] syscall_exit_to_user_mode+0x3c/0x40 kernel/entry/common.c:309 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f46a6322597 Code: 8d 3d 7c 8d 0b 00 e8 58 1d fa ff e8 a3 87 00 00 0f 1f 00 b8 68 00 00 00 0f 05 c3 0f 1f 84 00 00 00 00 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00 RSP: 002b:00007f46a4560b08 EFLAGS: 00000202 ORIG_RAX: 0000000000000027 RAX: 0000000000000010 RBX: 00007f46a4560c70 RCX: 00007f46a6322597 RDX: 00007f46a4560b40 RSI: 00007f46a4560c70 RDI: 0000000000000021 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 00007f46a65a2128 R14: 00007fff251a4290 R15: 00007fff251a4378