rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10506 jiffies, g=57485, q=3096 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295004885-4294994382), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10503 jiffies! g57485 f0x2 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:27848 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 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: 21 Comm: ksoftirqd/1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x7b/0x290 mm/kasan/generic.c:189 Code: 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe 10 7f 26 4d 85 f6 0f 84 39 01 00 00 48 f7 d3 4c 01 db 41 80 39 00 <0f> 85 c1 01 00 00 49 ff c1 48 ff c3 75 ee e9 1c 01 00 00 44 89 cb RSP: 0018:ffffc900001e08a0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff81630b36 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90ae2420 RBP: ffffc900001e0b10 R08: dffffc0000000000 R09: fffffbfff215c484 R10: fffffbfff215c485 R11: 1ffffffff215c484 R12: ffff888017749dc0 R13: ffff88801774a802 R14: 0000000000000001 R15: dffffc0000000001 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000040 CR3: 0000000075715000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:72 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] __lock_acquire+0xdc6/0x7c50 kernel/locking/lockdep.c:5019 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0x47/0x970 net/sched/sch_taprio.c:700 __run_hrtimer kernel/time/hrtimer.c:1747 [inline] __hrtimer_run_queues+0x554/0xd60 kernel/time/hrtimer.c:1811 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:nf_ip_checksum+0x344/0x520 net/netfilter/utils.c:38 Code: 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 0f 85 af 01 00 00 41 8b 07 83 e0 9f 83 c8 20 66 41 89 07 31 c0 48 83 c4 18 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 e8 6c d0 20 f9 e9 66 fd ff ff 89 RSP: 0018:ffffc900001b70a8 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffff888062539000 RCX: ffff888017749dc0 RDX: 0000000000000100 RSI: ffffffff8dda88e0 RDI: 0000000000000003 RBP: 0000000000000003 R08: ffff888017749dc0 R09: 0000000000000002 R10: 0000000000000002 R11: 0000000000000100 R12: 1ffff1100c4a7210 R13: 0000000000000001 R14: ffff888054521140 R15: ffff888062539080 nft_synproxy_do_eval+0x16e/0x570 net/netfilter/nft_synproxy.c:121 expr_call_ops_eval net/netfilter/nf_tables_core.c:214 [inline] nft_do_chain+0x408/0x1600 net/netfilter/nf_tables_core.c:264 nft_do_chain_inet+0x22b/0x300 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xb9/0x200 net/netfilter/core.c:614 nf_hook include/linux/netfilter.h:257 [inline] NF_HOOK+0x200/0x390 include/linux/netfilter.h:300 NF_HOOK+0x2ff/0x390 include/linux/netfilter.h:302 __netif_receive_skb_one_core net/core/dev.c:5581 [inline] __netif_receive_skb+0xcc/0x290 net/core/dev.c:5695 process_backlog+0x37c/0x6e0 net/core/dev.c:6023 __napi_poll+0xc0/0x460 net/core/dev.c:6590 napi_poll net/core/dev.c:6657 [inline] net_rx_action+0x5b1/0xad0 net/core/dev.c:6771 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596 run_ksoftirqd+0x98/0xf0 kernel/softirq.c:963 smpboot_thread_fn+0x64a/0xa40 kernel/smpboot.c:164 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295