rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=348c/1/0x4000000000000000 softirq=14806/14807 fqs=0
rcu: (detected by 0, t=10504 jiffies, g=13781, q=405 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6015 Comm: syz.0.28 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:match_held_lock+0x2/0xb0 kernel/locking/lockdep.c:5305
Code: 0f b9 3a 90 31 db 48 89 d8 5b 41 5e 41 5f c3 cc cc cc cc cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 56 <53> bb 01 00 00 00 48 39 77 10 74 6a 81 7f 20 00 00 20 00 72 5f 48
RSP: 0018:ffffc90000a08cf8 EFLAGS: 00000097
RAX: 0000000000000001 RBX: ffff888079888b30 RCX: 0000000000010203
RDX: ffff888079888000 RSI: ffff8880b8728258 RDI: ffff888079888b30
RBP: 00000000ffffffff R08: ffff888032e01317 R09: 0000000000000000
R10: ffff888032e01300 R11: ffffed10065c0263 R12: 0000000000000046
R13: ffff888079888000 R14: ffff8880b8728258 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125f1c000(0063) knlGS:00000000f54adb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000c34f96a CR3: 0000000076464000 CR4: 00000000003526f0
Call Trace:
__lock_is_held kernel/locking/lockdep.c:5601 [inline]
lock_is_held_type+0x8a/0x150 kernel/locking/lockdep.c:5940
lock_is_held include/linux/lockdep.h:249 [inline]
__run_hrtimer kernel/time/hrtimer.c:1743 [inline]
__hrtimer_run_queues+0x284/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:194
Code: f7 e8 7d eb 41 f6 f7 c3 00 02 00 00 74 05 e8 e0 19 6c f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 74 05 34 f6 65 8b 05 0d 98 23 07 85 c0 74 18 5b 41 5e c3 cc cc
RSP: 0018:ffffc900046bee88 EFLAGS: 00000206
RAX: 0000000000000016 RBX: 0000000000000282 RCX: 0000000080000202
RDX: 0000000000000002 RSI: ffffffff8d793a1d RDI: 0000000000000001
RBP: ffffc900046bf170 R08: ffffffff8f823177 R09: 1ffffffff1f0462e
R10: dffffc0000000000 R11: fffffbfff1f0462f R12: 0000000000000000
R13: dffffc0000000000 R14: ffff888032e012a8 R15: ffff888032e012a8
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
taprio_change+0x302c/0x3c40 net/sched/sch_taprio.c:1986
taprio_init+0x959/0xbd0 net/sched/sch_taprio.c:2126
qdisc_create+0x7ac/0xea0 net/sched/sch_api.c:1319
__tc_modify_qdisc net/sched/sch_api.c:1753 [inline]
tc_modify_qdisc+0x1547/0x2020 net/sched/sch_api.c:1817
rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6967
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x505/0x820 net/socket.c:2592
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
__sys_sendmsg+0x164/0x220 net/socket.c:2678
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x1dc/0x570 arch/x86/entry/syscall_32.c:307
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:332
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf70bd539
Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f54ad55c EFLAGS: 00000206 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10504 jiffies! g13781 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:28008 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5853 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 d4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 7f 93 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 63 93
RSP: 0000:ffffc90003fff820 EFLAGS: 00000293
RAX: ffffffff81b5654d RBX: 1ffff110170e8129 RCX: ffff888031e5bd00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003fff950 R08: ffffffff8f823177 R09: 1ffffffff1f0462e
R10: dffffc0000000000 R11: fffffbfff1f0462f R12: ffff8880b8740948
R13: dffffc0000000000 R14: ffff8880b863bb00 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125e1c000(0063) knlGS:0000000056b03440
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000056b1099c CR3: 0000000075dae000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x60a/0x1170 arch/x86/mm/tlb.c:1472
flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:103
wp_page_copy mm/memory.c:3785 [inline]
do_wp_page+0x1bb1/0x5810 mm/memory.c:4180
handle_pte_fault mm/memory.c:6289 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0x14c5/0x32b0 mm/memory.c:6580
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0023:0xf713db16
Code: 24 04 8b 7c 24 10 8d 89 cc 66 00 00 8d 04 3e 39 cd 89 45 38 0f 95 c1 29 fa 0f b6 c9 83 ca 01 c1 e1 02 09 f9 83 c9 01 89 4e 04 <89> 50 04 83 c6 08 8b 54 24 0c 89 f0 e8 a9 c9 ff ff e9 a9 f7 ff ff
RSP: 002b:00000000f74ffc60 EFLAGS: 00010206
RAX: 0000000056b10998 RBX: 0000000000000000 RCX: 0000000000008021
RDX: 0000000000014669 RSI: 0000000056b08978 RDI: 0000000000008020
RBP: 00000000f73ad6c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
hrtimer: interrupt took 110921244785 ns