syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=4dcc/1/0x4000000000000000 softirq=81154/81162 fqs=2
rcu: 	(detected by 0, t=10506 jiffies, g=82629, q=152 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14954 Comm: syz.8.2455 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:match_held_lock+0x7b/0xb0 kernel/locking/lockdep.c:5337
Code: c7 c2 70 03 e2 93 48 29 d0 48 c1 f8 03 48 ba 29 5c 8f c2 f5 28 5c 8f 48 0f af d0 bb 01 00 00 00 48 39 ca 74 02 31 db 89 d8 5b <41> 5e e9 b9 96 67 f5 cc 90 e8 97 f6 05 f9 85 c0 74 1c 83 3d 60 36
RSP: 0018:ffffc90000a08cc8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff8880545949d8 RCX: 0000000080010003
RDX: ffff888054593d80 RSI: ffff88804bbbf2c0 RDI: ffff8880545949d8
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141190 R12: 0000000000000046
R13: ffff888054593d80 R14: ffff88804bbbf2c0 R15: 0000000000000005
FS:  00007ff1b108b6c0(0000) GS:ffff88812538d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3151aff8 CR3: 000000006afc7000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 __lock_is_held kernel/locking/lockdep.c:5601 [inline]
 lock_is_held_type+0x89/0x150 kernel/locking/lockdep.c:5940
 lock_is_held include/linux/lockdep.h:249 [inline]
 advance_sched+0x1c6/0xc20 net/sched/sch_taprio.c:935
 __run_hrtimer kernel/time/hrtimer.c:1930 [inline]
 __hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:trace_mod_memcg_lruvec_state include/trace/events/memcg.h:41 [inline]
RIP: 0010:__mod_memcg_lruvec_state+0x1c1/0x360 mm/memcontrol.c:932
Code: 73 6a 89 c3 c1 e8 06 48 8d 3c c5 f0 ad 30 90 be 08 00 00 00 e8 30 68 f8 ff 48 0f a3 1d c8 18 f8 0d 73 09 e8 11 42 72 ff 84 c0 <74> 4d bf 01 00 00 00 e8 23 42 5b ff 65 8b 05 ec 9a 00 11 85 c0 74
RSP: 0018:ffffc900030cf488 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000080000003
RDX: 0000000000000000 RSI: ffffffff8c28adc0 RDI: ffffffff8c28ad80
RBP: 0000000000000001 R08: ffffffff9030adf7 R09: 1ffffffff20615be
R10: dffffc0000000000 R11: fffffbfff20615bf R12: ffff888031ae1088
R13: 000000000000000f R14: 0000000000000001 R15: 0000607edaa1b2f0
 mod_memcg_lruvec_state+0x1e7/0x270 mm/memcontrol.c:950
 mod_lruvec_state mm/memcontrol.c:973 [inline]
 lruvec_stat_mod_folio+0x239/0x3e0 mm/memcontrol.c:993
 __folio_mod_stat mm/rmap.c:1336 [inline]
 __folio_add_rmap mm/rmap.c:1428 [inline]
 __folio_add_file_rmap mm/rmap.c:1706 [inline]
 folio_add_file_rmap_ptes+0x689/0xc20 mm/rmap.c:1732
 set_pte_range+0x52e/0x8a0 mm/memory.c:5619
 finish_fault+0xe2f/0x1200 mm/memory.c:5757
 do_read_fault mm/memory.c:5897 [inline]
 do_fault mm/memory.c:6027 [inline]
 do_pte_missing+0x20bb/0x33f0 mm/memory.c:4550
 handle_pte_fault mm/memory.c:6411 [inline]
 __handle_mm_fault mm/memory.c:6549 [inline]
 handle_mm_fault+0x1bd7/0x3170 mm/memory.c:6718
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x1683/0x2720 mm/gup.c:1428
 populate_vma_page_range+0x2be/0x3c0 mm/gup.c:1860
 __mm_populate+0x25f/0x390 mm/gup.c:1963
 mm_populate include/linux/mm.h:4137 [inline]
 vm_mmap_pgoff+0x3aa/0x4f0 mm/util.c:586
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff1b019cdd9
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:00007ff1b108b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ff1b0415fa0 RCX: 00007ff1b019cdd9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007ff1b0232d69 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff1b0416038 R14: 00007ff1b0415fa0 R15: 00007ffd7b3bf738
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g82629 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:27544 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 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+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 9737 Comm: kworker/u8:17 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfd4/0x13d0 kernel/smp.c:892
Code: 89 ee 83 e6 01 31 ff e8 da 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 85 03 0c 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 6a 03 0c 00 eb e5 44 89
RSP: 0018:ffffc9000687f700 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b863c148 RCX: ffff88802c131ec0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000687f840 R08: ffffffff9030adf7 R09: 1ffffffff20615be
R10: dffffc0000000000 R11: fffffbfff20615bf R12: 1ffff110170e8169
R13: dffffc0000000000 R14: ffff8880b8740b48 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88812528d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f24838f9286 CR3: 000000000e74a000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
 smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2983
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 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
 </TASK>