rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (9 ticks this GP) idle=f1b4/1/0x4000000000000000 softirq=104825/104827 fqs=11
rcu: (detected by 0, t=10505 jiffies, g=106301, q=198 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 19820 Comm: syz.7.3686 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:100 [inline]
RIP: 0010:do_raw_spin_unlock+0x40/0x1e0 kernel/locking/spinlock_debug.c:141
Code: 83 c7 04 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 82 01 00 00 81 7b 04 ad 4e ad de <0f> 85 3f 01 00 00 be 04 00 00 00 48 89 df e8 0d 86 91 00 48 89 da
RSP: 0018:ffffc90000a08da8 EFLAGS: 00000046
RAX: 0000000000000007 RBX: ffff888079d0d2a8 RCX: ffffc90000a08d8c
RDX: 0000000000000000 RSI: ffffffff8df34f43 RDI: ffff888079d0d2ac
RBP: ffff888054a6d400 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 18a8ac06ed536fcf
R13: 18a8ac06ed536fcf R14: 0000000000000000 R15: ffff888054a6dc00
FS: 0000555557250500(0000) GS:ffff8881243db000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 00000000a1e41000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000006800 DR2: 0000000000009951
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_unlock include/linux/spinlock_api_smp.h:168 [inline]
_raw_spin_unlock+0x1e/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
advance_sched+0x62b/0xc80 net/sched/sch_taprio.c:987
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch.isra.0+0x2d3/0x1010 kernel/sched/core.c:5244
Code: 2f 0a 00 00 41 c7 87 e0 0d 00 00 00 00 00 00 e9 0f 04 00 00 49 8d 7f 48 e8 7a 7e c7 09 e8 b5 8b 3b 00 fb 48 8d bb a8 16 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84
RSP: 0018:ffffc9000367f930 EFLAGS: 00000206
RAX: 000000000000195f RBX: ffff8880568b4a00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8df5a478 RDI: ffff8880568b60a8
RBP: ffffc9000367f988 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff81d62fc2 R12: ffff888035474a00
R13: 0000000000000001 R14: ffffffff90dc56e4 R15: ffff8880b853b240
context_switch kernel/sched/core.c:5390 [inline]
__schedule+0x10f1/0x6820 kernel/sched/core.c:7188
preempt_schedule_common+0x42/0xc0 kernel/sched/core.c:7369
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
class_preempt_destructor include/linux/preempt.h:468 [inline]
try_to_wake_up+0x5f6/0x1900 kernel/sched/core.c:4154
wake_up_process kernel/sched/core.c:4434 [inline]
wake_up_q+0xa1/0x130 kernel/sched/core.c:1158
futex_wake+0x460/0x530 kernel/futex/waitwake.c:198
do_futex+0x32b/0x350 kernel/futex/syscalls.c:135
__do_sys_futex kernel/futex/syscalls.c:207 [inline]
__se_sys_futex kernel/futex/syscalls.c:188 [inline]
__x64_sys_futex+0x34f/0x4d0 kernel/futex/syscalls.c:188
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe7dc79c819
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:00007fff2b10e128 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe7dc79c819
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe7dca15fa8
RBP: 00000000000000f1 R08: 0000000000000001 R09: 0000000000000000
R10: 00007fe7dca15fa0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe7dca15fac R14: 00007fe7dca15fa8 R15: 00007fe7dca15fa0
rcu: rcu_preempt kthread starved for 10450 jiffies! g106301 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:27080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7282
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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:
CPU: 0 UID: 0 PID: 19562 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x589/0x1700 kernel/smp.c:892
Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 09 80 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 31
RSP: 0000:ffffc900034ef888 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fcfafd
RDX: ffff88801ffc2500 RSI: ffffffff81fcfad7 RDI: ffff88801ffc2500
RBP: ffff8880b8540f40 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a81e9 R14: 0000000000000001 R15: ffff8880b843c5c0
FS: 00007fb2555bb880(0000) GS:ffff8881242db000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c4ec05bfe8 CR3: 000000002656d000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000001800
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
__flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451
flush_tlb_page arch/x86/include/asm/tlbflush.h:345 [inline]
ptep_clear_flush+0x148/0x170 mm/pgtable-generic.c:104
wp_page_copy mm/memory.c:3925 [inline]
do_wp_page+0x12a4/0x4350 mm/memory.c:4320
handle_pte_fault mm/memory.c:6427 [inline]
__handle_mm_fault+0x1ab6/0x2a00 mm/memory.c:6549
handle_mm_fault+0x36d/0xa20 mm/memory.c:6718
do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fb2556b5db7
Code: 00 00 00 41 55 48 89 d0 49 89 fd 41 54 49 89 f4 53 4c 89 c3 48 83 ec 10 48 39 4f 60 0f 84 c1 00 00 00 42 f6 44 01 08 01 74 59 <48> 83 61 08 fe 48 3d ff 03 00 00 76 69 49 8b 55 70 49 8d 75 60 48
RSP: 002b:00007ffe853757f0 EFLAGS: 00010202
RAX: 0000000000006010 RBX: 00000000000001f0 RCX: 000055c4ec05bfe0
RDX: 0000000000006010 RSI: 000055c4ec055fd0 RDI: 00007fb2557f1ac0
RBP: 00007fb2557f1ac0 R08: 00000000000001f0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055c4ec055fd0
R13: 00007fb2557f1ac0 R14: 00000000000001f0 R15: 00007fb2557f1ac0