rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3561/1:b..l P4315/1:b..l
(detected by 0, t=10502 jiffies, g=8213, q=342)
task:syz-executor state:R running task stack:21856 pid: 4315 ppid: 4305 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6596
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
vprintk_emit+0x149/0x150 kernel/printk/printk.c:2275
dev_vprintk_emit+0x2cc/0x350 drivers/base/core.c:4638
dev_printk_emit+0xdd/0x120 drivers/base/core.c:4649
__netdev_printk+0x2ef/0x3d0 net/core/dev.c:11504
netdev_info+0x107/0x150 net/core/dev.c:11559
nsim_udp_tunnel_set_port+0x293/0x430 drivers/net/netdevsim/udp_tunnels.c:34
udp_tunnel_nic_device_sync_one net/ipv4/udp_tunnel_nic.c:-1 [inline]
udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:246 [inline]
__udp_tunnel_nic_device_sync+0x9d2/0x1320 net/ipv4/udp_tunnel_nic.c:289
udp_tunnel_nic_device_sync net/ipv4/udp_tunnel_nic.c:312 [inline]
__udp_tunnel_nic_add_port+0xb83/0xe80 net/ipv4/udp_tunnel_nic.c:531
udp_tunnel_nic_add_port include/net/udp_tunnel.h:336 [inline]
udp_tunnel_notify_add_rx_port+0x260/0x3a0 net/ipv4/udp_tunnel_core.c:130
geneve_socket_create drivers/net/geneve.c:614 [inline]
geneve_sock_add+0x53c/0x910 drivers/net/geneve.c:689
geneve_open+0xce/0x140 drivers/net/geneve.c:731
__dev_open+0x2b0/0x420 net/core/dev.c:1537
__dev_change_flags+0x20a/0x6a0 net/core/dev.c:8853
dev_change_flags+0x82/0x1a0 net/core/dev.c:8924
do_setlink+0xc01/0x3980 net/core/rtnetlink.c:2779
__rtnl_newlink net/core/rtnetlink.c:3450 [inline]
rtnl_newlink+0x1419/0x17d0 net/core/rtnetlink.c:3572
rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650
netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
__sys_sendto+0x423/0x580 net/socket.c:2063
__do_sys_sendto net/socket.c:2075 [inline]
__se_sys_sendto net/socket.c:2071 [inline]
__x64_sys_sendto+0xda/0xf0 net/socket.c:2071
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7feb7f6e7a3c
RSP: 002b:00007ffe22f58930 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007feb8045b620 RCX: 00007feb7f6e7a3c
RDX: 000000000000002c RSI: 00007feb8045b670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe22f58984 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007feb8045b670 R15: 0000000000000000
task:udevd state:R running task stack:25736 pid: 3561 ppid: 1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6571
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6596
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
_raw_spin_unlock_irqrestore+0xf6/0x100 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
__wake_up_common_lock kernel/sched/wait.c:140 [inline]
__wake_up_sync_key+0x11b/0x180 kernel/sched/wait.c:205
rcu_read_unlock include/linux/rcupdate.h:771 [inline]
sock_def_readable+0x201/0x250 net/core/sock.c:3096
__netlink_sendskb net/netlink/af_netlink.c:1264 [inline]
netlink_sendskb+0x97/0x130 net/netlink/af_netlink.c:1270
netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436
___sys_sendmsg+0x1f0/0x260 net/socket.c:2490
__sys_sendmsg net/socket.c:2519 [inline]
__do_sys_sendmsg net/socket.c:2528 [inline]
__se_sys_sendmsg+0x190/0x250 net/socket.c:2526
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdc8c50d407
RSP: 002b:00007ffe27a57540 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fdc8c41f880 RCX: 00007fdc8c50d407
RDX: 0000000000000000 RSI: 00007ffe27a575a0 RDI: 0000000000000004
RBP: 00005556ee7a5b70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b3
R13: 00005556ee77e9e0 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10571 jiffies! g8213 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:28032 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 4425 Comm: syz.3.27 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1690 [inline]
__hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__kasan_check_write+0x0/0x10 mm/kasan/shadow.c:37
Code: 8b eb 0a 48 c7 c7 b5 97 a2 8b 48 89 de e8 48 3a e2 07 31 ed eb d7 00 00 cc cc 89 f6 48 8b 0c 24 31 d2 e9 43 ef ff ff 0f 1f 00 <89> f6 48 8b 0c 24 ba 01 00 00 00 e9 30 ef ff ff 55 41 56 53 48 89
RSP: 0018:ffffc9000498fbe0 EFLAGS: 00000293
RAX: ffffffff83dad9c0 RBX: 0000000000000018 RCX: ffff88802a475940
RDX: 0000000000000000 RSI: 0000000000000018 RDI: ffffc9000498fc60
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad323e
R10: fffffbfff1ad323e R11: 1ffffffff1ad323d R12: 00007ffffffff000
R13: 00007f08f228bb68 R14: ffffc9000498fc60 R15: 00007f08f228bb50
instrument_copy_from_user include/linux/instrumented.h:135 [inline]
_copy_from_user+0xed/0x170 lib/usercopy.c:22
copy_from_user include/linux/uaccess.h:192 [inline]
restore_altstack+0x9a/0x360 kernel/signal.c:4252
__ia32_sys_rt_sigreturn+0x660/0x790 arch/x86/kernel/signal.c:677
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f08f2c1cba7
Code: ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89
RSP: 002b:00007f08f228c0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f08f2e63fa8 RCX: 00007f08f2c1cba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f08f2e63fa8
RBP: 00007f08f2e63fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f08f2e64038 R14: 00007ffc987e3a50 R15: 00007ffc987e3b38