rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (9511 ticks this GP) idle=491c/1/0x4000000000000000 softirq=27436/27436 fqs=469
rcu: hardirqs softirqs csw/system
rcu: number: 1279284 0 0
rcu: cputime: 11623 31881 39 ==> 43540(ms)
rcu: (t=10505 jiffies g=30829 q=2016 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 216 jiffies! g30829 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=16300
rcu: rcu_preempt kthread starved for 220 jiffies! g30829 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:27656 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x15ae/0x4660 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+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
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: 5760 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: dc 23 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 43 67 44 00 fb f4 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2c 89 cb 80 f9
RSP: 0018:ffffc900042378b8 EFLAGS: 000002d3
RAX: ffffffff813a9538 RBX: 0000000000000003 RCX: ffff88802b2e8000
RDX: 0000000000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1c7be0
RBP: ffffc90004237990 R08: ffffffff911bc5c7 R09: 1ffffffff22378b8
R10: dffffc0000000000 R11: fffffbfff22378b9 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff92000846f1c
FS: 00005555603ee500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3200600218 CR3: 000000002fcb8000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 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+0x613/0x9c0 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/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:3547
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: 0033:0x7f3205557fd7
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:00007ffdec443580 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555603ee500 RCX: 00007f3205557fd7
RDX: 0000000000000178 RSI: 00007f320063fe88 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000178
R13: 0000555560402860 R14: 00007ffdec443b60 R15: 00007f320063fe88
CPU: 0 PID: 9976 Comm: syz.3.1377 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x60 kernel/kcov.c:234
Code: f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 15 80 d2 7c 7e 65 8b
RSP: 0018:ffffc90000005fd0 EFLAGS: 00000246
RAX: ffffffff813b5989 RBX: ffffc90000006510 RCX: ffff88802ee6bc00
RDX: 0000000000000100 RSI: 0000000000000002 RDI: ffffc90000006510
RBP: ffffc90000006510 R08: ffff88802ee6bc00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc90000008000
R13: 1ffff92000000c23 R14: ffffc90000000000 R15: dffffc0000000000
FS: 00007f8de75b26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000002f7c6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
__read_once_word_nocheck+0x9/0x10 include/asm-generic/rwonce.h:66
deref_stack_reg+0x1ab/0x230 arch/x86/kernel/unwind_orc.c:406
unwind_next_frame+0x1781/0x2990 arch/x86/kernel/unwind_orc.c:648
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+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
packet_rcv+0x15b/0x1420 net/packet/af_packet.c:2278
dev_queue_xmit_nit+0xb0c/0xba0 net/core/dev.c:2385
xmit_one net/core/dev.c:3640 [inline]
dev_hard_start_xmit+0x150/0x790 net/core/dev.c:3660
sch_direct_xmit+0x251/0x4a0 net/sched/sch_generic.c:345
__dev_xmit_skb net/core/dev.c:3881 [inline]
__dev_queue_xmit+0x162a/0x3630 net/core/dev.c:4416
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+0xd4f/0x1260 net/ipv4/ip_output.c:235
NF_HOOK_COND include/linux/netfilter.h:293 [inline]
ip_output+0x2a5/0x3a0 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+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:5738 [inline]
tcp_rcv_established+0xb22/0x1d70 net/ipv4/tcp_input.c:6184
tcp_v4_do_rcv+0x6d3/0xba0 net/ipv4/tcp_ipv4.c:1735
tcp_v4_rcv+0x2358/0x2a60 net/ipv4/tcp_ipv4.c:2167
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: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+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:5689 [inline]
__netif_receive_skb_list_core+0x582/0x770 net/core/dev.c:5737
__netif_receive_skb_list net/core/dev.c:5789 [inline]
netif_receive_skb_list_internal+0x943/0xca0 net/core/dev.c:5880
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:580 [inline]
napi_gro_receive+0x553/0xaf0 net/core/gro.c:610
receive_buf+0x219d/0x37a0 drivers/net/virtio_net.c:1870
virtnet_receive drivers/net/virtio_net.c:2155 [inline]
virtnet_poll+0x60e/0x11e0 drivers/net/virtio_net.c:2229
__napi_poll+0xbb/0x460 net/core/dev.c:6650
napi_poll net/core/dev.c:6717 [inline]
net_rx_action+0x65f/0xcc0 net/core/dev.c:6853
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
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:mmdrop include/linux/sched/mm.h:53 [inline]
RIP: 0010:mmdrop_sched include/linux/sched/mm.h:82 [inline]
RIP: 0010:mmdrop_lazy_tlb_sched include/linux/sched/mm.h:109 [inline]
RIP: 0010:finish_task_switch+0x327/0x8f0 kernel/sched/core.c:5280
Code: 42 0f b6 04 30 84 c0 0f 85 a8 02 00 00 f7 03 20 00 00 00 0f 85 94 01 00 00 4c 89 ff be 04 00 00 00 e8 4d 12 82 00 f0 41 ff 0f <0f> 84 a5 00 00 00 81 7d b0 80 00 00 00 0f 84 ad 00 00 00 48 83 c4
RSP: 0018:ffffc90019237880 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff888025544348 RCX: ffffffff815d4953
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff888025544280
RBP: ffffc900192378d0 R08: ffff888025544283 R09: 1ffff11004aa8850
R10: dffffc0000000000 R11: ffffed1004aa8851 R12: ffff88802ee6c140
R13: 1ffff110171c79a9 R14: dffffc0000000000 R15: ffff888025544280
context_switch kernel/sched/core.c:5384 [inline]
__schedule+0x15b6/0x4660 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
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
futex_wake+0x41d/0x4f0 kernel/futex/waitwake.c:183
do_futex+0x35d/0x3e0 kernel/futex/syscalls.c:139
__do_sys_futex kernel/futex/syscalls.c:211 [inline]
__se_sys_futex+0x3a9/0x440 kernel/futex/syscalls.c:192
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: 0033:0x7f8de679ce59
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:00007f8de75b20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f8de6a15fa8 RCX: 00007f8de679ce59
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f8de6a15fac
RBP: 00007f8de6a15fa0 R08: 0000000000745a8c R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8de6a16038 R14: 00007fffacae0c10 R15: 00007fffacae0cf8