rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (10375 ticks this GP) idle=172c/1/0x4000000000000000 softirq=30198/30210 fqs=4287
rcu: hardirqs softirqs csw/system
rcu: number: 1410059 0 0
rcu: cputime: 15065 37433 44 ==> 52530(ms)
rcu: (t=10504 jiffies g=36837 q=2088 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 1447 jiffies! g36837 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=20155
rcu: rcu_preempt kthread starved for 1450 jiffies! g36837 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:26568 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: 5753 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 39 21 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 e3 f3 41 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:ffffc900044bf6d8 EFLAGS: 000002d3
RAX: ffffffff813aa578 RBX: 0000000000000003 RCX: ffff888076258000
RDX: 0000000000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8e60
RBP: ffffc900044bf7b0 R08: ffffffff911c55c7 R09: 1ffffffff2238ab8
R10: dffffc0000000000 R11: fffffbfff2238ab9 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff92000897ee0
FS: 0000555575647500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562dfb639130 CR3: 000000001e672000 CR4: 00000000003506e0
DR0: 0000000000000000 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+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:2607
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: 0033:0x7f476df57997
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:00007ffdde5deb30 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000555575647500 RCX: 00007f476df57997
RDX: 0000000000000004 RSI: 00007ffdde5deb8c RDI: 0000000000000003
RBP: 00007ffdde5df030 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffdde5deb8c R14: 00007ffdde5dec20 R15: 0000000000000000
CPU: 0 PID: 10098 Comm: syz.2.1216 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:unwind_next_frame+0xcf/0x2970 arch/x86/kernel/unwind_orc.c:482
Code: 00 85 ed 74 77 4c 89 74 24 60 48 89 5c 24 18 bf 01 00 00 00 e8 62 4e 21 00 49 8d 6c 24 50 48 89 e8 48 c1 e8 03 48 89 44 24 50 <42> 80 3c 28 00 74 08 48 89 ef e8 f2 20 a4 00 4c 8b 75 00 4d 85 f6
RSP: 0018:ffffc90000005ef8 EFLAGS: 00000a06
RAX: 1ffff92000000c03 RBX: 1ffff92000000bf9 RCX: ffffffff972cc403
RDX: ffff888029fc0000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc90000006018 R08: ffffc90000006090 R09: 0000000000000023
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc90000005fc8
R13: dffffc0000000000 R14: ffffc90000006000 R15: ffffffff8a8e909a
FS: 00007fb9b0e546c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000002e329000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
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+0x168/0x14a0 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:3644 [inline]
dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3660
sch_direct_xmit+0x25e/0x4c0 net/sched/sch_generic.c:345
__dev_xmit_skb net/core/dev.c:3881 [inline]
__dev_queue_xmit+0x165d/0x3660 net/core/dev.c:4416
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: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:5689 [inline]
__netif_receive_skb_list_core+0x2da/0x750 net/core/dev.c:5727
__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: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:6650
napi_poll net/core/dev.c:6717 [inline]
net_rx_action+0x616/0xc40 net/core/dev.c:6853
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:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7010
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 51 f6 cd f6 e8 7c 03 ff f6 fb bf 01 00 00 00 f1 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc90019857880 EFLAGS: 00000282
RAX: 390ddb8d37bc0500 RBX: 0000000000000000 RCX: 390ddb8d37bc0500
RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 0000000000000001
RBP: ffffc90019857920 R08: ffffffff8e8b15ef R09: 1ffffffff1d162bd
R10: dffffc0000000000 R11: fffffbfff1d162be R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200330af10
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:rcu_read_unlock_special+0x3d4/0x4d0 kernel/rcu/tree_plugin.h:-1
Code: 00 42 c6 44 2b 04 f8 75 26 f7 44 24 10 00 02 00 00 0f 84 c2 fc ff ff fb e9 bc fc ff ff 4c 89 ff 48 8b 74 24 10 e8 fc 00 00 00 aa fc ff ff e8 22 94 14 09 f7 44 24 10 00 02 00 00 0f 84 97 fc
RSP: 0018:ffffc900198579e0 EFLAGS: 00000246
RAX: 390ddb8d37bc0500 RBX: 1ffff9200330af40 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: 00000000ffffffff
RBP: ffffc90019857ac0 R08: ffffffff8e8b15ef R09: 1ffffffff1d162bd
R10: dffffc0000000000 R11: fffffbfff1d162be R12: 1ffff110053f8087
R13: dffffc0000000000 R14: 0000000080000000 R15: ffff888029fc0000
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:818 [inline]
sched_mm_cid_remote_clear_old kernel/sched/core.c:11940 [inline]
task_mm_cid_work+0x217/0x770 kernel/sched/core.c:11997
task_work_run+0x1d4/0x260 kernel/task_work.c:245
get_signal+0x1235/0x13f0 kernel/signal.c:2678
arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:315
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0033:0x7fb9aff9c819
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:00007fb9b0e540e8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fb9b0215fa8 RCX: 00007fb9aff9c819
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb9b0215fa8
RBP: 00007fb9b0215fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb9b0216038 R14: 00007fffa668bc20 R15: 00007fffa668bd08