rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (2 GPs behind) idle=1ec4/1/0x4000000000000002 softirq=33042/33043 fqs=1
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5632/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=33805, q=818 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:should_change_schedules net/sched/sch_taprio.c:-1 [inline]
RIP: 0010:advance_sched+0x7c0/0xc80 net/sched/sch_taprio.c:974
Code: 00 00 e8 83 b2 0a f8 4c 89 64 24 20 49 be 00 00 00 00 00 fc ff df 48 8b 44 24 10 e9 79 01 00 00 e8 65 b2 0a f8 4c 89 64 24 20 <48> 8b 44 24 10 e9 65 01 00 00 e8 51 b2 0a f8 e9 a1 00 00 00 e8 87
RSP: 0000:ffffc90000007d10 EFLAGS: 00000006
RAX: ffffffff89bb6edb RBX: 18ba832b4244a900 RCX: ffffffff8e68ef40
RDX: 0000000000010000 RSI: 0000000000000030 RDI: 0000000000000000
RBP: ffff888031d59c00 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f90 R12: ffff888057c5ec00
R13: ffff88803525b000 R14: dffffc0000000000 R15: ffff88803525b300
FS: 0000000000000000(0000) GS:ffff88812525d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f753ed1c CR3: 000000007b4f6000 CR4: 00000000003526f0
DR0: 0000000000000009 DR1: 00000000000000c9 DR2: 00000000000000f3
DR3: 00000000000000c0 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__run_hrtimer kernel/time/hrtimer.c:2032 [inline]
__hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:finish_task_switch+0x417/0xbc0 kernel/sched/core.c:5361
Code: 03 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 e9 1b 06 00 00 49 83 c4 48 4c 89 e7 e8 63 2a 1b 0a e8 1e 9d 39 00 fb 4c 8b 65 c8 <49> 8d bc 24 f8 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0000:ffffffff8e607b80 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff8880b863bda0 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8c293c00 RDI: ffffffff8194b0f2
RBP: ffffffff8e607bd0 R08: ffffffff903188f7 R09: 1ffffffff206311e
R10: dffffc0000000000 R11: fffffbfff206311f R12: ffffffff8e68ef40
R13: ffffffff8e68ef40 R14: dffffc0000000000 R15: 1ffff110170c77b4
context_switch kernel/sched/core.c:5507 [inline]
__schedule+0x17e1/0x56c0 kernel/sched/core.c:7228
schedule_idle+0x51/0x90 kernel/sched/core.c:7348
do_idle+0x4a6/0x540 kernel/sched/idle.c:384
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
rest_init+0x2de/0x300 init/main.c:717
start_kernel+0x38a/0x3e0 init/main.c:1175
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x157
task:syz-executor state:R running task stack:21928 pid:5632 tgid:5632 ppid:5617 task_flags:0x400140 flags:0x08080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7409
preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190
spin_unlock include/linux/spinlock.h:390 [inline]
wp_page_reuse+0x3df/0x520 mm/memory.c:3784
do_wp_page+0x1c50/0x4c70 mm/memory.c:4322
handle_pte_fault mm/memory.c:6443 [inline]
__handle_mm_fault mm/memory.c:6565 [inline]
handle_mm_fault+0x1490/0x3080 mm/memory.c:6734
do_user_addr_fault+0xa4d/0x1340 arch/x86/mm/fault.c:1343
handle_page_fault arch/x86/mm/fault.c:1483 [inline]
exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0023:0xf7041a67
RSP: 002b:00000000f753ed00 EFLAGS: 00010286
RAX: 00000000f753fe14 RBX: 00000000f73e5ff4 RCX: 00000000f753fe54
RDX: 0000000000000000 RSI: 0000000000003a98 RDI: 00000000f753fe14
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10493 jiffies! g33805 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:27080 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
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:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 9c 7b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 03 48 1c 00 fb f4 7c 03 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e40 EFLAGS: 00000246
RAX: ffff88812535d000 RBX: ffffffff819a6240 RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8c293c00 RDI: ffffffff819a6240
RBP: ffffc90000197f10 R08: ffff8880b87338db R09: 1ffff110170e671b
R10: dffffc0000000000 R11: ffffed10170e671c R12: 0000000000000000
R13: 1ffff11003b5f000 R14: 1ffff92000032fd0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff88812535d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000033e22ff8 CR3: 00000000760ec000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/kernel/process.c:766 [inline]
default_idle+0x9/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x2e0/0x540 kernel/sched/idle.c:355
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x157