rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (2 ticks this GP) idle=c104/1/0x4000000000000000 softirq=18885/18885 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5984/1:b..l rcu: (detected by 0, t=10502 jiffies, g=14717, q=407 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: kworker/u8:2 Not tainted 6.16.0-rc7-syzkaller-00100-gafd8c2c9e2e2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:65 Code: a6 39 c5 f5 eb a7 e8 bf e4 ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 40 8d e2 8b e9 bd fe ff ff cc cc cc RSP: 0018:ffffc90000a08c30 EFLAGS: 00000087 RAX: 0000000000000000 RBX: 0000000000000087 RCX: fb79c5abb3f0d600 RDX: 0000000000010000 RSI: ffffffff8be28d20 RDI: ffffffff8d9aa3bd RBP: ffffc90000a08d30 R08: ffffffff8fa1def7 R09: 1ffffffff1f43bde R10: dffffc0000000000 R11: fffffbfff1f43bdf R12: dffffc0000000000 R13: ffffffff81ae7768 R14: ffff8880b8727ad8 R15: ffff88801daa9e00 FS: 0000000000000000(0000) GS:ffff888125d23000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9755ae56c0 CR3: 000000002e56a000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:468 [inline] lock_release+0xbc/0x3e0 kernel/locking/lockdep.c:5891 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194 __run_hrtimer kernel/time/hrtimer.c:1757 [inline] __hrtimer_run_queues+0x408/0xc60 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:local_add arch/x86/include/asm/local.h:33 [inline] RIP: 0010:u64_stats_add include/linux/u64_stats_sync.h:89 [inline] RIP: 0010:macvlan_start_xmit+0x509/0x6e0 drivers/net/macvlan.c:589 Code: 8b 7c 24 10 48 8d 1c dd 70 cc bb 8d 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 3f 0d ba fb 48 8b 03 4a ff 44 20 18 <4e> 01 7c 20 20 eb 29 e8 2b fb 57 fb 48 81 c3 c8 0d 00 00 48 89 d8 RSP: 0018:ffffc90000a670c0 EFLAGS: 00000202 RAX: ffff888125d23000 RBX: ffffffff8dbbcc78 RCX: ffff88801daa9e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008 RBP: ffffc90000a67170 R08: ffff88801daa9e00 R09: 0000000000000002 R10: 0000000000000002 R11: 0000000000000000 R12: 0000607eda062628 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000056 __netdev_start_xmit include/linux/netdevice.h:5215 [inline] netdev_start_xmit include/linux/netdevice.h:5224 [inline] xmit_one net/core/dev.c:3830 [inline] dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3846 __dev_queue_xmit+0x1adf/0x3a70 net/core/dev.c:4713 neigh_output include/net/neighbour.h:539 [inline] ip6_finish_output2+0x11fb/0x16a0 net/ipv6/ip6_output.c:141 NF_HOOK include/linux/netfilter.h:317 [inline] ndisc_send_skb+0xb47/0x1400 net/ipv6/ndisc.c:513 ndisc_send_ns+0xcb/0x150 net/ipv6/ndisc.c:671 addrconf_dad_work+0xaae/0x14b0 net/ipv6/addrconf.c:4281 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 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 task:syz-executor state:R running task stack:21512 pid:5984 tgid:5984 ppid:5979 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_release+0xaf/0x3e0 kernel/locking/lockdep.c:5888 Code: 0a 00 00 00 0f 85 1e 02 00 00 49 81 3e 00 83 63 93 0f 84 11 02 00 00 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 48 8b 5c 24 20 48 c7 c7 bd a3 9a 8d e8 24 77 cf 09 65 ff 05 0d c4 01 11 c7 44 RSP: 0018:ffffc90003f3f1f0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000202 RCX: ab8e6c03027a0900 RDX: ffffffff90289c00 RSI: ffffffff8be28d20 RDI: ffffffff8be28ce0 RBP: dffffc0000000000 R08: 0000000000000022 R09: ffffffff8172aae5 R10: ffffc90003f3f378 R11: ffffffff81acfe40 R12: 00007ffd706e4748 R13: ffffffff8172aae5 R14: ffffffff8e13f0e0 R15: ffff8880259e9e00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_clone+0xb8/0x4f0 mm/rmap.c:288 anon_vma_fork+0x79/0x500 mm/rmap.c:351 dup_mmap+0x9eb/0x1ac0 mm/mmap.c:1801 dup_mm kernel/fork.c:1477 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1529 copy_process+0x16d3/0x3b80 kernel/fork.c:2169 kernel_clone+0x21e/0x870 kernel/fork.c:2599 __do_sys_clone kernel/fork.c:2742 [inline] __se_sys_clone kernel/fork.c:2726 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2726 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9754d85213 RSP: 002b:00007ffd706e4748 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9754d85213 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555879557d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000022f21 R15: 00007ffd706e48e0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g14717 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=7040 rcu: rcu_preempt kthread starved for 10502 jiffies! g14717 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:26760 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 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