rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10443 ticks this GP) idle=6494/1/0x4000000000000000 softirq=286051/286053 fqs=2911 rcu: hardirqs softirqs csw/system rcu: number: 1517766 0 0 rcu: cputime: 14582 37906 41 ==> 52490(ms) rcu: (t=10500 jiffies g=401405 q=1466 ncpus=2) rcu: rcu_preempt kthread timer wakeup didn't happen for 412 jiffies! g401405 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=246505 rcu: rcu_preempt kthread starved for 418 jiffies! g401405 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:26824 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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: 5763 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148 Code: 40 22 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d c3 29 43 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80 RSP: 0018:ffffc900044676d8 EFLAGS: 000002d3 RAX: ffffffff813aa578 RBX: 0000000000000003 RCX: ffff8880779c8000 RDX: 0000000000000000 RSI: ffffffff8acac960 RDI: ffffffff8b1c85a0 RBP: ffffc900044677b0 R08: ffffffff911c15c7 R09: 1ffffffff22382b8 R10: dffffc0000000000 R11: fffffbfff22382b9 R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff9200088cee0 FS: 00005555810f3500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f47c362c67c CR3: 0000000025268000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000200000000300 DR6: 00000000ffff0ff1 DR7: 0000000000000600 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] kvm_wait+0x23d/0x2a0 arch/x86/kernel/kvm.c:1058 pv_wait arch/x86/include/asm/paravirt.h:598 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x61a/0x9d0 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x23e/0x2c0 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:356 [inline] lock_sock_nested+0x6a/0x100 net/core/sock.c:3538 lock_sock include/net/sock.h:1780 [inline] tcp_recvmsg+0x214/0x860 net/ipv4/tcp.c:2606 inet_recvmsg+0x140/0x1f0 net/ipv4/af_inet.c:882 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg net/socket.c:1068 [inline] sock_read_iter+0x2d9/0x3e0 net/socket.c:1138 call_read_iter include/linux/fs.h:2012 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x46a/0x970 fs/read_write.c:470 ksys_read+0x150/0x260 fs/read_write.c:613 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: 0033:0x7f47c5957917 Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffd7530a180 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00005555810f3500 RCX: 00007f47c5957917 RDX: 0000000000000004 RSI: 00007ffd7530a1dc RDI: 0000000000000003 RBP: 00007ffd7530a680 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007ffd7530a1dc R14: 00007ffd7530a270 R15: 0000000000000000 CPU: 0 PID: 4715 Comm: syz.0.21915 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212 Code: 00 0f 0b 0f 1f 80 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d bc d4 03 0d 48 89 de 5b e9 33 5f 57 00 cc cc cc 0f 1e fa 48 8b 04 24 65 48 8b 0d 50 99 7c 7e 65 8b 15 51 99 7c RSP: 0018:ffffc90000005ef0 EFLAGS: 00000297 RAX: ffffffff8ef2dabc RBX: ffffffff8ef2dabc RCX: ffff88806a4f3c00 RDX: 0000000000000100 RSI: ffffffff88fa605c RDI: ffffffff88fa60a4 RBP: ffffffff8ef2dab8 R08: ffffc90000006090 R09: 0000000000000014 R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8ef2dab8 R13: ffffffff88fa60a4 R14: ffffffff88fa605c R15: ffffffff8ef2dac0 FS: 00007feee05f06c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f24a27e9e80 CR3: 00000000580c1000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __orc_find arch/x86/kernel/unwind_orc.c:99 [inline] orc_find arch/x86/kernel/unwind_orc.c:227 [inline] unwind_next_frame+0x4d9/0x2970 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 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_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x270 mm/slub.c:3852 dev_kfree_skb_any_reason+0x120/0x130 net/core/dev.c:3241 free_old_xmit_skbs+0x11a/0x3d0 drivers/net/virtio_net.c:780 start_xmit+0x161/0x1410 drivers/net/virtio_net.c:2420 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3632 [inline] dev_hard_start_xmit+0x246/0x740 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 neigh_output include/net/neighbour.h:543 [inline] ip_finish_output2+0xd3a/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_ack_snd_check net/ipv4/tcp_input.c:5736 [inline] tcp_rcv_established+0xb06/0x1d20 net/ipv4/tcp_input.c:6182 tcp_v4_do_rcv+0x4ed/0xb80 net/ipv4/tcp_ipv4.c:1734 tcp_v4_rcv+0x23bf/0x2af0 net/ipv4/tcp_ipv4.c:2166 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] gro_normal_one include/net/gro.h:464 [inline] napi_skb_finish net/core/gro.c:575 [inline] napi_gro_receive+0x565/0xb00 net/core/gro.c:605 receive_buf+0x2203/0x3820 drivers/net/virtio_net.c:1870 virtnet_receive drivers/net/virtio_net.c:2155 [inline] virtnet_poll+0x5dd/0x1280 drivers/net/virtio_net.c:2229 __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:smp_call_function_many_cond+0xcdc/0x1140 kernel/smp.c:850 Code: e8 79 f1 0a 00 0f 0b e9 50 f8 ff ff e8 6d f1 0a 00 e8 48 e9 08 09 48 85 db 0f 84 be fe ff ff e8 5a f1 0a 00 fb 83 7c 24 5c 00 <0f> 84 9a 01 00 00 44 39 a4 24 88 00 00 00 0f 83 8c 01 00 00 4d 8d RSP: 0018:ffffc900048174c0 EFLAGS: 00000202 RAX: ffffffff817c2b06 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc9000d9a1000 RSI: 000000000001f925 RDI: 000000000001f926 RBP: ffffc90004817640 R08: ffffffff911c1507 R09: 1ffffffff22382a0 R10: dffffc0000000000 R11: fffffbfff22382a1 R12: 0000000000000002 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8e3d140 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2222 [inline] text_poke_bp_batch+0x89a/0x990 arch/x86/kernel/alternative.c:-1 text_poke_bp+0xbc/0x100 arch/x86/kernel/alternative.c:2659 __static_call_transform+0x3ba/0x5b0 arch/x86/kernel/static_call.c:111 arch_static_call_transform+0x5f/0xc0 arch/x86/kernel/static_call.c:163 __static_call_update+0xef/0x5d0 kernel/static_call_inline.c:147 tracepoint_update_call kernel/tracepoint.c:317 [inline] tracepoint_add_func+0x8ca/0x990 kernel/tracepoint.c:358 tracepoint_probe_register_prio kernel/tracepoint.c:511 [inline] tracepoint_probe_register+0x5e/0x90 kernel/tracepoint.c:531 perf_trace_event_reg kernel/trace/trace_event_perf.c:129 [inline] perf_trace_event_init+0x4d2/0x9b0 kernel/trace/trace_event_perf.c:202 perf_trace_init+0x238/0x2d0 kernel/trace/trace_event_perf.c:226 perf_tp_event_init+0x8d/0x110 kernel/events/core.c:10204 perf_try_init_event+0x12b/0x3c0 kernel/events/core.c:11818 perf_init_event kernel/events/core.c:11888 [inline] perf_event_alloc+0xfa4/0x21b0 kernel/events/core.c:12169 __do_sys_perf_event_open kernel/events/core.c:12676 [inline] __se_sys_perf_event_open+0x61f/0x1c50 kernel/events/core.c:12567 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: 0033:0x7feedf79c799 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:00007feee05f0028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007feedfa15fa0 RCX: 00007feedf79c799 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000200000000200 RBP: 00007feedf832bd9 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007feedfa16038 R14: 00007feedfa15fa0 R15: 00007ffec04068c8