rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (0 ticks this GP) idle=1f3c/1/0x4000000000000000 softirq=149419/149419 fqs=0
rcu: (detected by 0, t=10506 jiffies, g=182209, q=202 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32728 Comm: syz.6.11311 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:mark_lock+0x3e/0x190 kernel/locking/lockdep.c:4775
Code: 03 00 48 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 89 d9 d3 e5 25 ff 1f 00 00 48 0f a3 05 d2 9e 42 14 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 90 09 88 95 eb 42 83 3d 99 2e
RSP: 0018:ffffc90000a38b90 EFLAGS: 00000003
RAX: 0000000000000073 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88805630ab40 RDI: ffff888056309f40
RBP: 0000000000000001 R08: ffffffff81b55266 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff237bf58 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812350b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f460b787ff8 CR3: 000000002bd62000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:4683 [inline]
__lock_acquire+0x6f6/0x2de0 kernel/locking/lockdep.c:5242
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:165 [inline]
_raw_spin_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:189
__run_hrtimer kernel/time/hrtimer.c:2083 [inline]
__hrtimer_run_queues+0x466/0xa10 kernel/time/hrtimer.c:2136
hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2255
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:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline]
RIP: 0010:deref_stack_reg+0x35/0x220 arch/x86/kernel/unwind_orc.c:419
Code: 83 ec 10 48 89 d3 49 89 f0 49 89 ff 48 be 00 00 00 00 00 fc ff df 48 83 c7 08 49 89 fc 49 c1 ec 03 41 80 3c 34 00 4c 89 04 24 <74> 13 e8 64 93 c7 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 48
RSP: 0018:ffffc90013676f20 EFLAGS: 00000246
RAX: fffffffffffffff0 RBX: ffffc900136770a8 RCX: 0000000000000000
RDX: ffffc900136770a8 RSI: dffffc0000000000 RDI: ffffc90013677070
RBP: 1ffffffff24ac38a R08: ffffc900136770f0 R09: 0000000000000000
R10: ffffc900136770b8 R11: fffff520026cee19 R12: 1ffff920026cee0e
R13: ffffffff92561c53 R14: ffffc90013677068 R15: ffffc90013677068
unwind_next_frame+0x19bd/0x2550 arch/x86/kernel/unwind_orc.c:-1
__unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
save_stack+0x122/0x230 mm/page_owner.c:183
__reset_page_owner+0x73/0x2a0 mm/page_owner.c:338
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
free_unref_folios+0xdc6/0x14e0 mm/page_alloc.c:3017
folios_put_refs+0x9e9/0xb30 mm/folio.c:1039
free_pages_and_swap_cache+0x41e/0x490 mm/swap_state.c:657
__tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:404
tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:529
exit_mmap+0x4b2/0xa40 mm/mmap.c:1328
__mmput+0x118/0x420 kernel/fork.c:1192
exit_mm+0x18e/0x240 kernel/exit.c:586
do_exit+0x6a8/0x2360 kernel/exit.c:967
do_group_exit+0x22d/0x2f0 kernel/exit.c:1123
get_signal+0x136a/0x1430 kernel/signal.c:3113
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbbf259f559
Code: Unable to access opcode bytes at 0x7fbbf259f52f.
RSP: 002b:00007fbbf34000e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fbbf2825fa8 RCX: 00007fbbf259f559
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fbbf2825fa8
RBP: 00007fbbf2825fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbbf2826038 R14: 00007fff4db2e050 R15: 00007fff4db2e138
rcu: rcu_preempt kthread starved for 10506 jiffies! g182209 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9c/0x340 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 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: 0 UID: 0 PID: 32732 Comm: syz.5.11312 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/15/2026
RIP: 0010:csd_lock_wait kernel/smp.c:389 [inline]
RIP: 0010:csd_lock kernel/smp.c:422 [inline]
RIP: 0010:smp_call_function_many_cond+0x61e/0x1500 kernel/smp.c:970
Code: b6 04 04 84 c0 0f 85 d5 03 00 00 44 8b 3b 44 89 fe 83 e6 01 31 ff e8 21 7a 0c 00 41 83 e7 01 75 07 e8 06 75 0c 00 eb 3f f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 04 04 84 c0 75 0f f7 03 01
RSP: 0018:ffffc9000e837320 EFLAGS: 00000293
RAX: ffffffff81bc9f6e RBX: ffff8880b8342008 RCX: ffff888077335dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000e837470 R08: ffff88807733735f R09: 1ffff1100ee66e6b
R10: dffffc0000000000 R11: 0000000000000000 R12: 1ffff11017068401
R13: 0000000000000001 R14: ffff8880b8342000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88812340b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32721ff8 CR3: 0000000074a6c000 CR4: 00000000003526f0
Call Trace:
__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+0x910/0x10b0 arch/x86/mm/tlb.c:1435
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:461 [inline]
tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:403
tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:529
free_ldt_pgtables+0x192/0x360 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:229 [inline]
exit_mmap+0x1b7/0xa40 mm/mmap.c:1300
__mmput+0x118/0x420 kernel/fork.c:1192
exit_mm+0x18e/0x240 kernel/exit.c:586
do_exit+0x6a8/0x2360 kernel/exit.c:967
do_group_exit+0x22d/0x2f0 kernel/exit.c:1123
get_signal+0x136a/0x1430 kernel/signal.c:3113
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f036559f559
Code: Unable to access opcode bytes at 0x7f036559f52f.
RSP: 002b:00007f03665320e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f0365825fa8 RCX: 00007f036559f559
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0365825fa8
RBP: 00007f0365825fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0365826038 R14: 00007ffe55584c40 R15: 00007ffe55584d28