rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (2 GPs behind) idle=0244/1/0x4000000000000000 softirq=19813/19813 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=16261, q=478 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5828 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d 54 12 d3 0b 48 89 de 5b e9 53 8b 5a 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 b0 6e 92 65 8b 15 58 ac RSP: 0018:ffffc90000007d38 EFLAGS: 00000097 RAX: ffffffff81ada6a8 RBX: ffff8880b8827d08 RCX: 0000000000010000 RDX: ffff888026e0bc80 RSI: 0000000000000003 RDI: 0000000000000020 RBP: ffffc90000007e90 R08: ffffffff8f7d0477 R09: 1ffffffff1efa08e R10: dffffc0000000000 R11: fffffbfff1efa08f R12: ffff888025ab5ac0 R13: 0000000000000003 R14: ffff8880b8827ac0 R15: 0000000000000001 FS: 000055556b7b1500(0000) GS:ffff888126135000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9a00bb7198 CR3: 000000007209a000 CR4: 00000000003526f0 Call Trace: __remove_hrtimer kernel/time/hrtimer.c:1115 [inline] __run_hrtimer kernel/time/hrtimer.c:1757 [inline] __hrtimer_run_queues+0x3a7/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:memset_orig+0x75/0xb0 arch/x86/lib/memset_64.S:92 Code: 89 47 30 48 89 47 38 48 8d 7f 40 75 d8 0f 1f 84 00 00 00 00 00 89 d1 83 e1 38 74 14 c1 e9 03 66 0f 1f 44 00 00 ff c9 48 89 07 <48> 8d 7f 08 75 f5 83 e2 07 74 0a ff ca 88 07 48 8d 7f 01 75 f6 4c RSP: 0018:ffffc9000409f4b0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffc9000409f620 RCX: 0000000000000000 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc9000409f640 RBP: dffffc0000000000 R08: ffffc9000409f647 R09: 0000000000000000 R10: ffffc9000409f638 R11: fffff52000813ec9 R12: ffffc9000409f5e8 R13: ffffc9000409f638 R14: ffffc9000409f5e8 R15: ffffc9000409f630 unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5650 [inline] __kvmalloc_node_noprof+0x5cd/0x910 mm/slub.c:7112 xt_jumpstack_alloc net/netfilter/x_tables.c:1356 [inline] xt_replace_table+0x18a/0x790 net/netfilter/x_tables.c:1395 __do_replace+0x15a/0x980 net/ipv6/netfilter/ip6_tables.c:1081 do_replace net/ipv6/netfilter/ip6_tables.c:1158 [inline] do_ip6t_set_ctl+0xa16/0xce0 net/ipv6/netfilter/ip6_tables.c:1644 nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2360 __sys_setsockopt net/socket.c:2385 [inline] __do_sys_setsockopt net/socket.c:2391 [inline] __se_sys_setsockopt net/socket.c:2388 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2388 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9a0099163a Code: ff ff ff c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 49 89 ca b8 36 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 RSP: 002b:00007ffeeea173c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007ffeeea17450 RCX: 00007f9a0099163a RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00000000000003b8 R09: 0079746972756365 R10: 00007f9a00bb7800 R11: 0000000000000202 R12: 00007f9a00bb77a0 R13: 00007ffeeea173ec R14: 0000000000000000 R15: 00007f9a00bb7e60 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g16261 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=6984 rcu: rcu_preempt kthread starved for 10500 jiffies! g16261 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:27288 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245