rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (8885 ticks this GP) idle=7aec/1/0x4000000000000000 softirq=74896/74916 fqs=4117 rcu: hardirqs softirqs csw/system rcu: number: 1228712 46 0 rcu: cputime: 18426 34063 50 ==> 52490(ms) rcu: (t=10500 jiffies g=95465 q=2281 ncpus=2) CPU: 0 PID: 18765 Comm: syz.6.3347 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__unwind_start+0x0/0x7e0 arch/x86/kernel/unwind_orc.c:687 Code: a3 00 e9 6a fe ff ff 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 3d ff ff ff 4c 89 ff e8 6a f2 a3 00 e9 30 ff ff ff 0f 1f 44 00 00 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 48 89 4c 24 RSP: 0018:ffffc90000006140 EFLAGS: 00000246 RAX: ffffffff8132a350 RBX: ffffc90000006200 RCX: ffffc900000061d0 RDX: 0000000000000000 RSI: ffff88801cf18000 RDI: ffffc90000006148 RBP: ffffc900000061d0 R08: ffffc90000006558 R09: 0000000000000000 R10: ffffc90000006280 R11: fffffbfff22388a1 R12: ffff88801cf18000 R13: 00000000000000f0 R14: ffffffff8175c220 R15: 0000000000000000 FS: 00007f2ff6ec86c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f295ffe9f00 CR3: 000000007e7ea000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 skb_clone+0x1eb/0x370 net/core/skbuff.c:1915 dev_queue_xmit_nit+0x24d/0xbb0 net/core/dev.c:2353 xmit_one net/core/dev.c:3628 [inline] dev_hard_start_xmit+0x148/0x740 net/core/dev.c:3648 sch_direct_xmit+0x25e/0x4c0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3869 [inline] __dev_queue_xmit+0x165d/0x3660 net/core/dev.c:4404 dev_queue_xmit include/linux/netdevice.h:3113 [inline] neigh_hh_output include/net/neighbour.h:527 [inline] neigh_output include/net/neighbour.h:541 [inline] ip_finish_output2+0xcec/0x11e0 net/ipv4/ip_output.c:235 NF_HOOK_COND include/linux/netfilter.h:293 [inline] ip_output+0x2a1/0x3b0 net/ipv4/ip_output.c:436 dst_output include/net/dst.h:467 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x1049/0x1950 net/ipv4/ip_output.c:540 __tcp_transmit_skb+0x1d6b/0x33f0 net/ipv4/tcp_output.c:1425 tcp_validate_incoming+0xf13/0x2250 net/ipv4/tcp_input.c:5899 tcp_rcv_established+0x7de/0x1d20 net/ipv4/tcp_input.c:6164 tcp_v4_do_rcv+0x4ed/0xb80 net/ipv4/tcp_ipv4.c:1735 tcp_v4_rcv+0x23bf/0x2af0 net/ipv4/tcp_ipv4.c:2167 ip_protocol_deliver_rcu+0x20e/0x3f0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2ca/0x510 net/ipv4/ip_input.c:233 NF_HOOK+0x32d/0x3b0 include/linux/netfilter.h:304 dst_input include/net/dst.h:477 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0xa4c/0xd70 net/ipv4/ip_input.c:639 ip_list_rcv+0x3f2/0x440 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5677 [inline] __netif_receive_skb_list_core+0x583/0x750 net/core/dev.c:5725 __netif_receive_skb_list net/core/dev.c:5777 [inline] netif_receive_skb_list_internal+0x943/0xca0 net/core/dev.c:5868 gro_normal_list include/net/gro.h:451 [inline] napi_complete_done+0x329/0x820 net/core/dev.c:6208 virtqueue_napi_complete drivers/net/virtio_net.c:450 [inline] virtnet_poll+0xa9c/0x1280 drivers/net/virtio_net.c:2236 __napi_poll+0xc0/0x460 net/core/dev.c:6638 napi_poll net/core/dev.c:6705 [inline] net_rx_action+0x616/0xc40 net/core/dev.c:6841 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5758 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25 RSP: 0018:ffffc9000bda75a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 40b493ebd1bc3e00 RDX: 0000000000000002 RSI: ffffffff8acadb60 RDI: ffffffff8b1c8de0 RBP: ffffc9000bda76c0 R08: dffffc0000000000 R09: 1ffffffff274c738 R10: dffffc0000000000 R11: fffffbfff274c739 R12: 1ffff920017b4ec0 R13: ffffffff8cfa2f98 R14: 0000000000000246 R15: dffffc0000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] pgd_dtor arch/x86/mm/pgtable.c:148 [inline] pgd_free+0x2c/0x130 arch/x86/mm/pgtable.c:487 mm_free_pgd kernel/fork.c:809 [inline] __mmdrop+0xb4/0x3d0 kernel/fork.c:925 mmdrop include/linux/sched/mm.h:54 [inline] mmdrop_sched include/linux/sched/mm.h:82 [inline] mmdrop_lazy_tlb_sched include/linux/sched/mm.h:109 [inline] finish_task_switch+0x3dc/0x8f0 kernel/sched/core.c:5280 context_switch kernel/sched/core.c:5384 [inline] __schedule+0x155b/0x45a0 kernel/sched/core.c:6700 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 smp_call_function_single+0x48d/0x5a0 kernel/smp.c:652 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x5be/0x920 kernel/events/core.c:2959 __do_sys_perf_event_open kernel/events/core.c:12957 [inline] __se_sys_perf_event_open+0x1836/0x1c50 kernel/events/core.c:12609 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2ff5f9c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2ff6ec8028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f2ff6215fa0 RCX: 00007f2ff5f9c819 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480 RBP: 00007f2ff6032c91 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2ff6216038 R14: 00007f2ff6215fa0 R15: 00007fffa92e3e08