rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=c394/1/0x4000000000000000 softirq=13999/14000 fqs=63
rcu: 	(t=10502 jiffies g=14017 q=417 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 6469 jiffies! g14017 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=8176
rcu: rcu_preempt kthread starved for 6472 jiffies! g14017 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:27240 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x30d/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
 </TASK>
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: 5765 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x52e/0x9c0 kernel/locking/qspinlock.c:511
Code: 8b 44 24 18 c6 00 00 48 8b 44 24 10 42 0f b6 04 28 84 c0 0f 85 1b 01 00 00 48 8d 43 01 c6 00 01 41 bc 00 80 ff ff eb 07 f3 90 <41> ff c4 74 47 43 0f b6 04 2e 84 c0 75 2b 80 3b 00 75 eb 48 89 df
RSP: 0018:ffffc900045979a0 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffff888078140cd8 RCX: ffff88807b39da00
RDX: 0000000000000000 RSI: ffffffff8acacce0 RDI: ffffffff8b1d4020
RBP: ffffc90004597a90 R08: ffffffff911f05c7 R09: 1ffffffff223e0b8
R10: dffffc0000000000 R11: fffffbfff223e0b9 R12: 00000000ffffc349
R13: dffffc0000000000 R14: 1ffff1100f02819b R15: ffff8880b8f30001
FS:  00005555701c4500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557e11da38 CR3: 0000000077113000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 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/0x2b0 kernel/locking/spinlock_debug.c:115
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 lock_sock_nested+0x6a/0x100 net/core/sock.c:3546
 lock_sock include/net/sock.h:1780 [inline]
 tcp_sendmsg+0x21/0x50 net/ipv4/tcp.c:1347
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 sock_write_iter+0x2dc/0x420 net/socket.c:1161
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6a609592d7
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:00007fff08080af0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555701c4500 RCX: 00007f6a609592d7
RDX: 0000000000000340 RSI: 00007f6a5d3ffcc0 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000340
R13: 00005555701dbf10 R14: 00007fff080810d0 R15: 00007f6a5d3ffcc0
 </TASK>
CPU: 0 PID: 6694 Comm: syz.1.246 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:unwind_get_return_address+0x58/0xc0 arch/x86/kernel/unwind_orc.c:369
Code: 31 ff 89 ee e8 f9 e1 4b 00 85 ed 74 4a 48 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 db 85 a4 00 48 8b 3b <e8> 83 49 1e 00 89 c5 31 ff 89 c6 e8 c8 e1 4b 00 85 ed 74 20 e8 0f
RSP: 0018:ffffc900000060a0 EFLAGS: 00000246
RAX: ffffffff813bb267 RBX: ffffc90000006110 RCX: 0000000000000100
RDX: ffff88805cb71e00 RSI: 0000000000000002 RDI: ffffffff81e031e8
RBP: 0000000000000002 R08: ffff88805cb71e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff81e00c6e
R13: ffffc900000064e0 R14: dffffc0000000000 R15: 1ffff92000000c22
FS:  00007f6a2a3166c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0f995eb840 CR3: 00000000773e7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26
 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+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 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+0xf8/0x290 mm/slub.c:3852
 dev_kfree_skb_any_reason+0x120/0x130 net/core/dev.c:3246
 free_old_xmit_skbs+0x11a/0x3b0 drivers/net/virtio_net.c:781
 start_xmit+0x16d/0x1470 drivers/net/virtio_net.c:2427
 __netdev_start_xmit include/linux/netdevice.h:4998 [inline]
 netdev_start_xmit include/linux/netdevice.h:5012 [inline]
 xmit_one net/core/dev.c:3649 [inline]
 dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3665
 sch_direct_xmit+0x251/0x4a0 net/sched/sch_generic.c:345
 __dev_xmit_skb net/core/dev.c:3886 [inline]
 __dev_queue_xmit+0x18b8/0x37e0 net/core/dev.c:4440
 dev_queue_xmit include/linux/netdevice.h:3170 [inline]
 neigh_hh_output include/net/neighbour.h:531 [inline]
 neigh_output include/net/neighbour.h:545 [inline]
 ip_finish_output2+0xd4f/0x1260 net/ipv4/ip_output.c:235
 NF_HOOK_COND include/linux/netfilter.h:293 [inline]
 ip_output+0x29f/0x440 net/ipv4/ip_output.c:436
 dst_output include/net/dst.h:470 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x1056/0x1960 net/ipv4/ip_output.c:540
 __tcp_transmit_skb+0x1dd6/0x3470 net/ipv4/tcp_output.c:1427
 tcp_ack_snd_check net/ipv4/tcp_input.c:5768 [inline]
 tcp_rcv_established+0xb30/0x1dd0 net/ipv4/tcp_input.c:6215
 tcp_v4_do_rcv+0x6d3/0xba0 net/ipv4/tcp_ipv4.c:1744
 tcp_v4_rcv+0x2358/0x2a60 net/ipv4/tcp_ipv4.c:2176
 ip_protocol_deliver_rcu+0x20a/0x3f0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2c3/0x510 net/ipv4/ip_input.c:233
 NF_HOOK+0x32d/0x3b0 include/linux/netfilter.h:304
 dst_input include/net/dst.h:480 [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+0xa36/0xd60 net/ipv4/ip_input.c:639
 ip_list_rcv+0x3ed/0x440 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5713 [inline]
 __netif_receive_skb_list_core+0x582/0x770 net/core/dev.c:5761
 __netif_receive_skb_list net/core/dev.c:5813 [inline]
 netif_receive_skb_list_internal+0x943/0xca0 net/core/dev.c:5904
 gro_normal_list include/net/gro.h:452 [inline]
 napi_complete_done+0x329/0x820 net/core/dev.c:6244
 virtqueue_napi_complete drivers/net/virtio_net.c:451 [inline]
 virtnet_poll+0xb6e/0x1300 drivers/net/virtio_net.c:2243
 __napi_poll+0xbb/0x460 net/core/dev.c:6674
 napi_poll net/core/dev.c:6741 [inline]
 net_rx_action+0x65f/0xcc0 net/core/dev.c:6877
 handle_softirqs+0x27d/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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7011
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 61 fa c1 f6 e8 ac 03 f3 f6 fb bf 01 00 00 00 <e8> 31 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc9000340fc20 EFLAGS: 00000282
RAX: ffdecccb89c66400 RBX: 0000000000000000 RCX: ffdecccb89c66400
RDX: dffffc0000000000 RSI: ffffffff8acacce0 RDI: 0000000000000001
RBP: ffffc9000340fcd0 R08: ffffffff8e8c626f R09: 1ffffffff1d18c4d
R10: dffffc0000000000 R11: fffffbfff1d18c4e R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000681f84
 irqentry_exit+0x67/0x70 kernel/entry/common.c:441
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:preempt_schedule+0x0/0xd0 kernel/sched/core.c:6885
Code: 4c 89 f7 e8 22 3d 45 f7 eb af 66 0f 1f 00 bf 01 00 00 00 e8 62 ff c1 f6 e8 fd fd ff ff bf 01 00 00 00 e8 b3 fd c1 f6 c3 66 90 <f3> 0f 1e fa 55 48 89 e5 41 56 53 48 83 e4 e0 48 83 ec 60 65 48 8b
RSP: 0018:ffffc9000340fd90 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88805cb72808 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8acacce0 RDI: 00000000ffffffff
RBP: ffffc9000340fde0 R08: ffffffff8e8c626f R09: 1ffffffff1d18c4d
R10: dffffc0000000000 R11: fffffbfff1d18c4e R12: dffffc0000000000
R13: ffff88805cb73388 R14: ffff88805cb72808 R15: ffff88805cb72770
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x40/0x50 kernel/locking/spinlock.c:202
 task_work_run+0x197/0x260 kernel/task_work.c:241
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:180
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
 __syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6a2939e159
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:00007f6a2a316028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: 0000000000000008 RBX: 00007f6a29625fa0 RCX: 00007f6a2939e159
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007f6a2943506b R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6a29626038 R14: 00007f6a29625fa0 R15: 00007ffdc3b4eb28
 </TASK>