rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=dc94/1/0x4000000000000000 softirq=122204/122208 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P22160/1:b..l
rcu: (detected by 1, t=10506 jiffies, g=108033, q=300 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 22165 Comm: syz.6.5538 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:mark_usage kernel/locking/lockdep.c:4674 [inline]
RIP: 0010:__lock_acquire+0x6ab/0xd20 kernel/locking/lockdep.c:5191
Code: 8b 3c 24 85 c0 0f 84 19 06 00 00 41 8b 46 20 a9 00 00 18 00 0f 84 b3 00 00 00 4c 89 f6 ba 08 00 00 00 e8 88 25 00 00 45 31 ff <85> c0 0f 84 f5 05 00 00 83 3d f6 56 ff 17 00 75 13 48 63 44 24 20
RSP: 0018:ffffc90000007b30 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff93470338
RDX: 0000000000000008 RSI: ffff88807d8ee640 RDI: ffff88807d8edac0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff89678104
R10: dffffc0000000000 R11: ffffffff89678040 R12: 0000000000000003
R13: 0000000000000003 R14: ffff88807d8ee640 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125d06000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d922ff8 CR3: 000000000df38000 CR4: 0000000000350ef0
Call Trace:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:929
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:ptlock_ptr include/linux/mm.h:3008 [inline]
RIP: 0010:pte_lockptr include/linux/mm.h:3032 [inline]
RIP: 0010:__pte_offset_map_lock+0x128/0x210 mm/pgtable-generic.c:400
Code: e8 7d 28 ae ff 4d 21 f5 49 c1 ed 06 4b 8d 2c 2f 48 83 c5 28 48 89 e8 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 80 3c 30 00 <74> 08 48 89 ef e8 7e d8 13 00 48 8b 6d 00 48 89 ef e8 02 33 3e 09
RSP: 0018:ffffc9000d6ff568 EFLAGS: 00000246
RAX: 1ffffd40003b002d RBX: ffff88807bafddf8 RCX: ffff88807d8edac0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffea0001d80168 R08: 0000000000000000 R09: ffffffff82121989
R10: dffffc0000000000 R11: fffff52001adfefe R12: 1ffff1100f75fbbf
R13: 0000000001d80140 R14: dffffc0000000000 R15: ffffea0000000000
pte_offset_map_lock include/linux/mm.h:3133 [inline]
zap_pte_range mm/memory.c:1840 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0xc81/0x4370 mm/memory.c:2017
unmap_single_vma mm/memory.c:2060 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2104
exit_mmap+0x240/0xb40 mm/mmap.c:1280
__mmput+0x118/0x430 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:954
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
__do_sys_exit_group kernel/exit.c:1118 [inline]
__se_sys_exit_group kernel/exit.c:1116 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f76b918efc9
Code: Unable to access opcode bytes at 0x7f76b918ef9f.
RSP: 002b:00007fff6b4e47e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f76b918efc9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fff6b4e484c R08: 000000056b4e48df R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000000d6
R13: 00000000000927c0 R14: 00000000000aff92 R15: 00007fff6b4e48a0
task:syz.2.5536 state:R running task stack:25608 pid:22160 tgid:22160 ppid:20242 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113
preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
_raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
zap_pte_range mm/memory.c:1884 [inline]
zap_pmd_range mm/memory.c:1946 [inline]
zap_pud_range mm/memory.c:1975 [inline]
zap_p4d_range mm/memory.c:1996 [inline]
unmap_page_range+0x3a7f/0x4370 mm/memory.c:2017
unmap_single_vma mm/memory.c:2060 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:2104
exit_mmap+0x240/0xb40 mm/mmap.c:1280
__mmput+0x118/0x430 kernel/fork.c:1133
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:954
do_group_exit+0x21c/0x2d0 kernel/exit.c:1107
__do_sys_exit_group kernel/exit.c:1118 [inline]
__se_sys_exit_group kernel/exit.c:1116 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116
x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0c4d78efc9
RSP: 002b:00007ffe5b0a4738 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0c4d78efc9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe5b0a479c R08: 000000055b0a482f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000081
R13: 00000000000927c0 R14: 00000000000afef3 R15: 00007ffe5b0a47f0
rcu: rcu_preempt kthread starved for 10506 jiffies! g108033 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
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+0x4bc/0x870 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: 10723 Comm: kworker/u8:11 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877
Code: 89 ee 83 e6 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 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 45 6f 0b 00 eb e4 44
RSP: 0018:ffffc9000c907640 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170c8441 RCX: ffff888032111e40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000c9077c0 R08: ffffffff8f9e1577 R09: 1ffffffff1f3c2ae
R10: dffffc0000000000 R11: fffffbfff1f3c2af R12: ffff8880b8642208
R13: dffffc0000000000 R14: ffff8880b873b240 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125e06000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555818c9808 CR3: 000000000df38000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2713 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2923
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:852
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245