rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=b904/1/0x4000000000000000 softirq=43064/43065 fqs=2
rcu: (detected by 1, t=10505 jiffies, g=34629, q=460 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10588 Comm: syz.2.1664 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:debug_object_activate+0x2c7/0x420 lib/debugobjects.c:833
Code: 5c fd 4d 8b 1c 24 4d 85 db 74 3c 48 89 df 44 89 fe 2e e8 fc 1e a1 06 84 c0 74 2c ff 05 72 d3 d9 0a eb 22 43 0f b6 04 37 84 c0 <0f> 85 28 01 00 00 c7 45 00 03 00 00 00 48 8b 7c 24 08 48 8b 34 24
RSP: 0018:ffffc90000007c88 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88807f683340 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007b60
RBP: ffff88803325de80 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f6c R12: ffff88803325de88
R13: ffff88803325de70 R14: dffffc0000000000 R15: 1ffff1100664bbd0
FS: 0000000000000000(0000) GS:ffff888125c55000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3010dff8 CR3: 00000000645ea000 CR4: 0000000000350ef0
Call Trace:
debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline]
debug_activate kernel/time/hrtimer.c:484 [inline]
enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088
__run_hrtimer kernel/time/hrtimer.c:1778 [inline]
__hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__nr_to_section include/linux/mmzone.h:1933 [inline]
RIP: 0010:__pfn_to_section include/linux/mmzone.h:2075 [inline]
RIP: 0010:lookup_page_ext mm/page_ext.c:251 [inline]
RIP: 0010:page_ext_lookup+0x50/0x180 mm/page_ext.c:520
Code: ee 16 e9 2d 01 00 00 e8 0e 81 91 ff 41 bf 00 00 04 00 49 bd 00 00 00 00 00 fc ff df 4c 89 f7 4c 89 fe e8 53 83 91 ff 4d 39 fe <0f> 83 ef 00 00 00 48 c7 c0 80 e4 ad 99 48 c1 e8 03 42 80 3c 28 00
RSP: 0018:ffffc900032c7318 EFLAGS: 00000287
RAX: ffffffff822edadd RBX: 000000000005930d RCX: ffff888030aa8000
RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822eebf7
R10: dffffc0000000000 R11: fffff940002c9869 R12: 000000000005930d
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000001000
page_ext_iter_begin include/linux/page_ext.h:132 [inline]
page_table_check_clear+0x278/0x700 mm/page_table_check.c:78
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:714 [inline]
zap_present_folio_ptes mm/memory.c:1505 [inline]
zap_present_ptes mm/memory.c:1590 [inline]
do_zap_pte_range mm/memory.c:1691 [inline]
zap_pte_range mm/memory.c:1735 [inline]
zap_pmd_range mm/memory.c:1827 [inline]
zap_pud_range mm/memory.c:1856 [inline]
zap_p4d_range mm/memory.c:1877 [inline]
unmap_page_range+0x3249/0x41c0 mm/memory.c:1898
unmap_single_vma mm/memory.c:1941 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1985
exit_mmap+0x248/0xb50 mm/mmap.c:1284
__mmput+0x118/0x420 kernel/fork.c:1121
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x640/0x22e0 kernel/exit.c:943
do_group_exit+0x21c/0x2d0 kernel/exit.c:1104
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7c19b8e929
Code: Unable to access opcode bytes at 0x7f7c19b8e8ff.
RSP: 002b:00007f7c1aa320e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f7c19db5fa8 RCX: 00007f7c19b8e929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7c19db5fa8
RBP: 00007f7c19db5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7c19db5fac
R13: 0000000000000000 R14: 00007ffc273ebf10 R15: 00007ffc273ebff8
rcu: rcu_preempt kthread starved for 10495 jiffies! g34629 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 10587 Comm: syz.0.1663 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 60 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 0b 74 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 f0 73 0b
RSP: 0018:ffffc900033374a0 EFLAGS: 00000293
RAX: ffffffff81b4e7e0 RBX: ffff8880b873cb40 RCX: ffff888026c6bc00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003337600 R08: ffffffff8fa101f7 R09: 1ffffffff1f4203e
R10: dffffc0000000000 R11: fffffbfff1f4203f R12: 1ffff110170c86b5
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b86435a8
FS: 0000000000000000(0000) GS:ffff888125d55000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000000f0 CR3: 000000005a103000 CR4: 0000000000350ef0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
exit_mmap+0x44c/0xb50 mm/mmap.c:1297
__mmput+0x118/0x420 kernel/fork.c:1121
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x640/0x22e0 kernel/exit.c:943
do_group_exit+0x21c/0x2d0 kernel/exit.c:1104
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f47b7f8e929
Code: Unable to access opcode bytes at 0x7f47b7f8e8ff.
RSP: 002b:00007f47b8d3b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f47b81b6088 RCX: 00007f47b7f8e929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f47b81b6088
RBP: 00007f47b81b6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f47b81b608c
R13: 0000000000000000 R14: 00007fff5711d5b0 R15: 00007fff5711d698