rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16637/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=297289, q=1409 ncpus=2)
task:syz.0.10376 state:R running task stack:23640 pid:16637 tgid:16630 ppid:11161 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x32/0xe0 kernel/rcu/tree_plugin.h:435
Code: 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 79 5c c0 11 48 8d 9f c4 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c <84> c0 75 4f ff 0b 75 1d 4c 8d b7 c8 04 00 00 4c 89 f0 48 c1 e8 03
RSP: 0018:ffffc9000cd663f0 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: ffff8880359d04c4 RCX: 0000000000000046
RDX: 0000000000000004 RSI: ffffffff8e4b1fe5 RDI: ffff8880359d0000
RBP: 1ffffffff2294601 R08: ffffc9000cd66eb8 R09: 0000000000000000
R10: ffffc9000cd66518 R11: fffff520019acca5 R12: 1ffff11006b3a098
R13: ffffffff8176f27f R14: ffffc9000cd664c8 R15: dffffc0000000000
rcu_read_unlock include/linux/rcupdate.h:873 [inline]
class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0x1baf/0x2550 arch/x86/kernel/unwind_orc.c:709
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950
__slab_free+0x274/0x2c0 mm/slub.c:5767
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4612 [inline]
slab_alloc_node mm/slub.c:4945 [inline]
__kmalloc_cache_noprof+0x2ab/0x660 mm/slub.c:5511
_kmalloc_noprof include/linux/slab.h:969 [inline]
_kzalloc_noprof include/linux/slab.h:1290 [inline]
ref_tracker_alloc+0x15b/0x4b0 lib/ref_tracker.c:270
__netdev_tracker_alloc include/linux/netdevice.h:4523 [inline]
netdev_hold include/linux/netdevice.h:4552 [inline]
neigh_parms_alloc+0x1ee/0x500 net/core/neighbour.c:1773
inetdev_init+0x117/0x4d0 net/ipv4/devinet.c:280
inetdev_event+0x307/0x15e0 net/ipv4/devinet.c:1590
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2291 [inline]
call_netdevice_notifiers net/core/dev.c:2305 [inline]
register_netdevice+0x18a4/0x1eb0 net/core/dev.c:11489
ppp_unit_register drivers/net/ppp/ppp_generic.c:1214 [inline]
ppp_dev_configure+0x8b1/0xb10 drivers/net/ppp/ppp_generic.c:1275
ppp_nl_newlink+0x252/0x2f0 drivers/net/ppp/ppp_generic.c:1349
rtnl_newlink_create+0x305/0x7b0 net/core/rtnetlink.c:3949
__rtnl_newlink net/core/rtnetlink.c:4078 [inline]
rtnl_newlink+0x166d/0x1c30 net/core/rtnetlink.c:4195
rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7112
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x54e/0x850 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2b57d9de99
RSP: 002b:00007f2b58ccb028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2b58026090 RCX: 00007f2b57d9de99
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000003
RBP: 00007f2b57e33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2b58026128 R14: 00007f2b58026090 R15: 00007ffe9a0a2988
rcu: rcu_preempt kthread starved for 3004 jiffies! g297289 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 543 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67
Code: 89 e7 e8 c3 da bc 00 e9 1e fd ff ff 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> 8b 07 e9 98 93 5b 0a cc cc cc cc cc cc cc cc 90 90 90 90 90 90
RSP: 0018:ffffc90000a07df8 EFLAGS: 00000202
RAX: ffffc90000a08401 RBX: 1ffff92000140fd6 RCX: 1ffff92000140f01
RDX: ffffc90000a08438 RSI: 0000000000000002 RDI: ffffc90000a08438
RBP: 1ffffffff22fa0c6 R08: ffffc90000a08440 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 1ffff92000140fd7
R13: ffffc90000a09000 R14: ffffc90000a07ea8 R15: ffffc90000a01000
FS: 0000000000000000(0000) GS:ffff88812505a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f62b8231eb8 CR3: 000000000e946000 CR4: 00000000003526f0
Call Trace:
deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline]
unwind_next_frame+0xca5/0x2550 arch/x86/kernel/unwind_orc.c:614
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4612 [inline]
slab_alloc_node mm/slub.c:4945 [inline]
kmem_cache_alloc_node_noprof+0x355/0x610 mm/slub.c:5017
kmalloc_reserve net/core/skbuff.c:615 [inline]
__alloc_skb+0x276/0x7a0 net/core/skbuff.c:715
alloc_skb include/linux/skbuff.h:1384 [inline]
synproxy_send_client_synack+0x175/0xde0 net/netfilter/nf_synproxy_core.c:463
nft_synproxy_eval_v4+0x362/0x4e0 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x335/0x550 net/netfilter/nft_synproxy.c:141
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:280 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
__netif_receive_skb_one_core net/core/dev.c:6215 [inline]
__netif_receive_skb net/core/dev.c:6328 [inline]
process_backlog+0xa34/0x1860 net/core/dev.c:6679
__napi_poll+0xaa/0x330 net/core/dev.c:7738
napi_poll net/core/dev.c:7801 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:7958
handle_softirqs+0x225/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x1ad/0x7a0 net/core/skbuff.c:699
alloc_skb include/linux/skbuff.h:1384 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
nsim_dev_trap_report_work+0x25f/0xb40 drivers/net/netdevsim/dev.c:922
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog