rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (3 GPs behind) idle=f844/0/0x1 softirq=15041/15053 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=10937, q=383 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
RIP: 0010:check_preemption_disabled+0x3/0xe0 lib/smp_processor_id.c:13
Code: 27 8c 48 c7 c6 e0 b3 27 8c eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 <41> 56 53 65 8b 05 57 d3 6d 07 65 8b 0d 4c d3 6d 07 f7 c1 ff ff ff
RSP: 0018:ffffc90000007be0 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000010003
RDX: 0000000000010000 RSI: ffffffff8df0e0cb RDI: ffffffff8c27b400
RBP: ffff888077171150 R08: ffff888077171087 R09: 1ffff1100ee2e210
R10: dffffc0000000000 R11: ffffed100ee2e211 R12: ffff88803163c300
R13: ffffffff89b6f06f R14: ffff88803163c2c0 R15: ffffffff8e494ec0
FS: 0000000000000000(0000) GS:ffff888125463000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcddb4e868 CR3: 000000007d54a000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
lock_release+0xa1/0x3d0 kernel/locking/lockdep.c:5888
__raw_spin_unlock include/linux/spinlock_api_smp.h:167 [inline]
_raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:389 [inline]
advance_sched+0x99f/0xc90 net/sched/sch_taprio.c:987
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
hrtimer_interrupt+0x42b/0x1010 kernel/time/hrtimer.c:1911
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x460 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:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: fe 6c 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 43 82 1b 00 fb f4 fc e9 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000246
RAX: 00000000000bd287 RBX: ffffffff819a8c8d RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8def4b08 RDI: ffffffff8c27b400
RBP: ffffffff8e407eb0 R08: ffff8880b863395b R09: 1ffff110170c672b
R10: dffffc0000000000 R11: ffffed10170c672c R12: ffffffff90118bb0
R13: 1ffffffff1c929d8 R14: 0000000000000000 R15: 0000000000000000
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:191 [inline]
do_idle+0x1bd/0x500 kernel/sched/idle.c:332
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430
rest_init+0x2de/0x300 init/main.c:760
start_kernel+0x385/0x3d0 init/main.c:1210
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x147
rcu: rcu_preempt kthread starved for 10502 jiffies! g10937 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:27744 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7005
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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: 6010 Comm: syz-executor.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xce5/0x12c0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 24 e6 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 cf e1 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 b3 e1
RSP: 0018:ffffc90004127580 EFLAGS: 00000293
RAX: ffffffff81b9bbfd RBX: 1ffff110170c8515 RCX: ffff88802c6d0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900041276a8 R08: ffffffff90118bb7 R09: 1ffffffff2023176
R10: dffffc0000000000 R11: fffffbfff2023177 R12: ffff8880b86428a8
R13: dffffc0000000000 R14: ffff8880b873bf80 R15: 0000000000000000
FS: 000000003ff504c0(0000) GS:ffff888125563000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001493b93 CR3: 0000000037270000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x5c3/0x10c0 arch/x86/mm/tlb.c:1472
dup_mmap+0x17a2/0x1d90 mm/mmap.c:1906
dup_mm kernel/fork.c:1530 [inline]
copy_mm+0x13b/0x4b0 kernel/fork.c:1582
copy_process+0x18b6/0x3cf0 kernel/fork.c:2223
kernel_clone+0x248/0x8e0 kernel/fork.c:2654
__do_sys_clone kernel/fork.c:2795 [inline]
__se_sys_clone kernel/fork.c:2779 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2779
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x470ea2
Code: 89 e7 e8 91 53 fa ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffe06e10f70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffe06e10f70 RCX: 0000000000470ea2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 000000003ff50790 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffe06e11170