rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16240/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=72881, q=381 ncpus=2)
task:syz.0.2590 state:R running task stack:26000 pid:16240 tgid:16239 ppid:5618 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17d4/0x5820 kernel/sched/core.c:7270
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7592
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x910 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5913
Code: ff ff ff e8 40 dc 3f 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 92 e7 f0 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 07 23 da
RSP: 0018:ffffc90006e1f340 EFLAGS: 00000292
RAX: fe60e402776d2200 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000821d9986 RSI: ffffffff8e6fac39 RDI: ffffffff8c6d8b80
RBP: ffff88807ca9ddc0 R08: 5e00000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8ed5c6e0 R12: ffffffff8ed5c6e0
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
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:183
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:338
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
__free_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
__slab_free+0x274/0x2c0 mm/slub.c:5815
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_kmalloc+0x22/0xb0 mm/kasan/common.c:406
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5414 [inline]
__kmalloc_noprof+0x36b/0x720 mm/slub.c:5439
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
new_dir fs/proc/proc_sysctl.c:965 [inline]
get_subdir fs/proc/proc_sysctl.c:1009 [inline]
sysctl_mkdir_p fs/proc/proc_sysctl.c:1319 [inline]
__register_sysctl_table+0xc02/0x1370 fs/proc/proc_sysctl.c:1394
mpls_dev_sysctl_register+0x196/0x280 net/mpls/af_mpls.c:1453
mpls_add_dev net/mpls/af_mpls.c:1506 [inline]
mpls_dev_notify+0x3b7/0xd30 net/mpls/af_mpls.c:1651
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
call_netdevice_notifiers net/core/dev.c:2327 [inline]
register_netdevice+0x18a4/0x1eb0 net/core/dev.c:11541
tun_set_iff+0x82b/0xf20 drivers/net/tun.c:2956
__tun_chr_ioctl+0x7e5/0x1e70 drivers/net/tun.c:3239
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f543a79e159
RSP: 002b:00007f543b6c6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f543aa25fa0 RCX: 00007f543a79e159
RDX: 0000200000000040 RSI: 00000000400454ca RDI: 0000000000000009
RBP: 00007f543a835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f543aa26038 R14: 00007f543aa25fa0 R15: 00007ffdf0ac02a8
rcu: rcu_preempt kthread starved for 816 jiffies! g72881 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:R running task stack:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17d4/0x5820 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7362
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6313 Comm: kworker/u8:14 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: krds_cp_wq#11/1 rds_connect_worker
RIP: 0010:do_xdp_generic+0xcc/0x12f0 net/core/dev.c:-1
Code: 2b 18 42 c7 44 2b 20 f3 f3 f3 f3 e8 9e 6f 17 f8 4a c7 44 2b 04 00 00 00 00 42 c7 44 2b 0c 00 00 00 00 66 42 c7 44 2b 10 00 00 <4c> 89 64 24 50 4d 85 e4 0f 84 89 00 00 00 4c 8d b4 24 a0 00 00 00
RSP: 0018:ffffc90000006e60 EFLAGS: 00000246
RAX: ffffffff89b04402 RBX: 1ffff92000000ddc RCX: ffff888031ce8000
RDX: 8000000000000100 RSI: 0000000000000100 RDI: 0000000000000000
RBP: ffffc90000007050 R08: 0000000000000100 R09: 1ffffffff20f404f
R10: dffffc0000000000 R11: fffffbfff20f4050 R12: 0000000000000000
R13: dffffc0000000000 R14: f8f8f8f8f8f8f8f8 R15: ffffc90000007220
FS: 0000000000000000(0000) GS:ffff888124ce0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffea293dff8 CR3: 0000000076340000 CR4: 00000000003526f0
Call Trace:
__netif_receive_skb_core+0x10e3/0x30c0 net/core/dev.c:6074
__netif_receive_skb_one_core net/core/dev.c:6262 [inline]
__netif_receive_skb net/core/dev.c:6377 [inline]
netif_receive_skb_internal net/core/dev.c:6463 [inline]
netif_receive_skb+0x1fe/0xbf0 net/core/dev.c:6522
NF_HOOK+0xa4/0x3a0 include/linux/netfilter.h:325
br_handle_frame_finish+0x1136/0x1950 net/bridge/br_input.c:-1
br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:325 [inline]
br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x127f/0x1510 net/bridge/br_input.c:442
__netif_receive_skb_core+0x989/0x30c0 net/core/dev.c:6151
__netif_receive_skb_one_core net/core/dev.c:6262 [inline]
__netif_receive_skb net/core/dev.c:6377 [inline]
process_backlog+0x727/0x18b0 net/core/dev.c:6728
__napi_poll+0xaa/0x330 net/core/dev.c:7787
napi_poll net/core/dev.c:7850 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8007
handle_softirqs+0x226/0x860 kernel/softirq.c:645
do_softirq+0x77/0xd0 kernel/softirq.c:546
__local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
__inet6_bind+0x386/0xf30 net/ipv6/af_inet6.c:419
kernel_bind+0x13e/0x1c0 net/socket.c:3675
rds_tcp_conn_path_connect+0x53b/0x920 net/rds/tcp_connect.c:175
rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176
process_one_work kernel/workqueue.c:3387 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
kthread+0x38b/0x480 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