rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (1 GPs behind) idle=5f1c/1/0x4000000000000000 softirq=16317/16318 fqs=96
rcu: (t=10501 jiffies g=16937 q=1017 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10309 jiffies! g16937 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=12235
rcu: rcu_preempt kthread starved for 10312 jiffies! g16937 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
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:26856 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
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:ffffc900000079a0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff88807bc58098 RCX: ffffffff8ce93440
RDX: 0000000000000100 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20
RBP: ffffc90000007a90 R08: ffffffff911e75c7 R09: 1ffffffff223ceb8
R10: dffffc0000000000 R11: fffffbfff223ceb9 R12: 00000000ffffecd0
R13: dffffc0000000000 R14: 1ffff1100f78b013 R15: ffff8880b8e30001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555594714e8 CR3: 0000000062152000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
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 include/linux/spinlock.h:351 [inline]
tcp_write_timer+0x2d/0x280 net/ipv4/tcp_timer.c:707
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x570/0x810 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
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:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 4c 1d 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 77 3c 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:ffffffff8ce07d80 EFLAGS: 000002c6
RAX: bb047a54a78c4400 RBX: ffffffff81628c14 RCX: bb047a54a78c4400
RDX: 0000000000000001 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20
RBP: ffffffff8ce07eb8 R08: ffff8880b8e36bab R09: 1ffff110171c6d75
R10: dffffc0000000000 R11: ffffed10171c6d76 R12: 1ffffffff19c0fbc
R13: dffffc0000000000 R14: 1ffffffff19d2688 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x334/0x5c0 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
rest_init+0x2e2/0x300 init/main.c:744
arch_call_rest_init+0xe/0x10 init/main.c:840
start_kernel+0x461/0x4e0 init/main.c:1085
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b
CPU: 1 PID: 6941 Comm: syz.2.335 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:seqcount_lockdep_reader_access+0x19a/0x1d0 include/linux/seqlock.h:105
Code: 00 4d 85 e4 75 16 e8 c5 bf 0f 00 eb 15 e8 be bf 0f 00 e8 89 a2 14 09 4d 85 e4 74 ea e8 af bf 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 43 c7 44 3e 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc900001ef2e0 EFLAGS: 00000246
RAX: ffffffff817725c1 RBX: 0000000000000000 RCX: ffff888028b91e00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900001ef398 R08: ffffffff911e75c7 R09: 1ffffffff223ceb8
R10: dffffc0000000000 R11: fffffbfff223ceb9 R12: 0000000000000200
R13: 000001fb63109b96 R14: 1ffff9200003de5c R15: dffffc0000000000
FS: 00007fcd263006c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000240 CR3: 0000000077c34000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
ktime_get_with_offset+0x94/0x330 kernel/time/timekeeping.c:889
ktime_get_real include/linux/timekeeping.h:79 [inline]
net_timestamp_set net/core/dev.c:2207 [inline]
dev_queue_xmit_nit+0x8c9/0xba0 net/core/dev.c:2357
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_transmit_skb net/ipv4/tcp_output.c:1445 [inline]
tcp_write_xmit+0x1550/0x66f0 net/ipv4/tcp_output.c:2784
__tcp_push_pending_frames+0x96/0x330 net/ipv4/tcp_output.c:2969
tcp_push_pending_frames include/net/tcp.h:2012 [inline]
tcp_data_snd_check net/ipv4/tcp_input.c:5658 [inline]
tcp_rcv_established+0xfc5/0x1d70 net/ipv4/tcp_input.c:6092
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:finish_task_switch+0x267/0x8f0 kernel/sched/core.c:5255
Code: 2e 09 85 c0 0f 84 30 01 00 00 48 85 db 0f 85 4f 01 00 00 0f 1f 44 00 00 4c 89 e7 e8 43 32 38 09 e8 8e 0a 30 00 fb 4c 8b 65 b8 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900048ef760 EFLAGS: 00000286
RAX: 6cf2295f3aaec400 RBX: 0000000000000000 RCX: 6cf2295f3aaec400
RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20
RBP: ffffc900048ef7b0 R08: ffffffff911e75ff R09: 1ffffffff223cebf
R10: dffffc0000000000 R11: fffffbfff223cec0 R12: ffff888028b91e00
R13: 1ffff110171e79a9 R14: dffffc0000000000 R15: ffff8880b8f3cd48
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
smp_call_function_single+0x48d/0x5a0 kernel/smp.c:652
task_function_call kernel/events/core.c:120 [inline]
perf_install_in_context+0x5bb/0x920 kernel/events/core.c:2951
__do_sys_perf_event_open kernel/events/core.c:12949 [inline]
__se_sys_perf_event_open+0x1841/0x1c60 kernel/events/core.c:12601
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: 0033:0x7fcd2539de99
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:00007fcd26300028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007fcd25626090 RCX: 00007fcd2539de99
RDX: ffffff7fffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007fcd25433eaf R08: 0000000000000008 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcd25626128 R14: 00007fcd25626090 R15: 00007fff9a1c9358