rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 ticks this GP) idle=d79c/1/0x4000000000000000 softirq=69418/69418 fqs=6
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=60421, q=309 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13909 Comm: syz.3.2419 Not tainted 6.16.0-next-20250804-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:105 [inline]
RIP: 0010:do_raw_spin_unlock+0xc2/0x240 kernel/locking/spinlock_debug.c:141
Code: 8d 7b 08 4c 89 fd 48 c1 ed 03 42 0f b6 44 25 00 84 c0 0f 85 42 01 00 00 41 8b 07 65 8b 0d 3a 8b 02 11 39 c8 0f 85 d4 00 00 00 <43> 80 7c 25 00 00 74 08 4c 89 f7 e8 9e 19 85 00 49 c7 06 ff ff ff
RSP: 0018:ffffc90000a08ba8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffffffff99cde0e0 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff99cde0e0
RBP: 1ffffffff339bc1d R08: ffffffff99cde0e3 R09: 1ffffffff339bc1c
R10: dffffc0000000000 R11: fffffbfff339bc1d R12: dffffc0000000000
R13: 1ffffffff339bc1e R14: ffffffff99cde0f0 R15: ffffffff99cde0e8
FS: 0000000000000000(0000) GS:ffff888125d17000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3251eff8 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_unlock_irqrestore+0x78/0x110 kernel/locking/spinlock.c:194
debug_object_activate+0x2e2/0x420 lib/debugobjects.c:836
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+0x108/0x410 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:preempt_count_add+0x4d/0x1a0 kernel/sched/core.c:5829
Code: 84 c0 0f 85 f1 00 00 00 83 3d 0e e8 1b 18 00 75 07 65 8b 05 f5 94 10 11 65 01 3d ee 94 10 11 48 c7 c0 40 e3 ab 99 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 ec 00 00 00 83 3d df e7 1b 18 00 75 11
RSP: 0018:ffffc9000da172f8 EFLAGS: 00000a02
RAX: 1ffffffff3357c68 RBX: 0000000000000160 RCX: ffffffff99abe303
RDX: 0000000000000000 RSI: 000000000005f422 RDI: 0000000000000001
RBP: ffffc9000da17650 R08: ffffea00017d0887 R09: 1ffffd40002fa110
R10: dffffc0000000000 R11: fffff940002fa111 R12: dffffc0000000000
R13: 1ffffd40002fa113 R14: 000000000005f422 R15: dffffc0000000000
rcu_read_lock_sched include/linux/rcupdate.h:930 [inline]
pfn_valid+0xb3/0x490 include/linux/mmzone.h:2162
page_table_check_clear+0x21/0x700 mm/page_table_check.c:70
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
get_and_clear_full_ptes include/linux/pgtable.h:725 [inline]
zap_present_folio_ptes mm/memory.c:1499 [inline]
zap_present_ptes mm/memory.c:1581 [inline]
do_zap_pte_range mm/memory.c:1682 [inline]
zap_pte_range mm/memory.c:1726 [inline]
zap_pmd_range mm/memory.c:1818 [inline]
zap_pud_range mm/memory.c:1847 [inline]
zap_p4d_range mm/memory.c:1868 [inline]
unmap_page_range+0x3445/0x4370 mm/memory.c:1889
unmap_single_vma mm/memory.c:1932 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1976
exit_mmap+0x248/0xb50 mm/mmap.c:1280
__mmput+0x118/0x420 kernel/fork.c:1130
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
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:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f107c78eb69
Code: Unable to access opcode bytes at 0x7f107c78eb3f.
RSP: 002b:00007f107d5970e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f107c9b5fa8 RCX: 00007f107c78eb69
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f107c9b5fac
RBP: 00007f107c9b5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f107c9b5fac
R13: 0000000000000000 R14: 00007ffef88827e0 R15: 00007ffef88828c8
task:kworker/u8:0 state:R running task stack:21224 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 fb 32 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90000117980 EFLAGS: 00000206
RAX: fb09a61e40d46000 RBX: 0000000000000000 RCX: fb09a61e40d46000
RDX: 0000000000000000 RSI: ffffffff8dba88e7 RDI: ffffffff8be34280
RBP: ffffffff8b47f142 R08: 0000000000000000 R09: ffffffff8b47f142
R10: dffffc0000000000 R11: ffffffff8b47f070 R12: 0000000000000002
R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: rcu_preempt kthread starved for 10490 jiffies! g60421 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:27352 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
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+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 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: 0 UID: 0 PID: 13894 Comm: syz.4.2412 Not tainted 6.16.0-next-20250804-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5e 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 5e 0b 00 eb e4 44
RSP: 0018:ffffc9000d84f340 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 1ffff110170e7f61 RCX: ffff8880253a0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000d84f4c0 R08: ffffffff8fa38837 R09: 1ffffffff1f47106
R10: dffffc0000000000 R11: fffffbfff1f47107 R12: ffff8880b873fb08
R13: dffffc0000000000 R14: ffff8880b863b1c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125c17000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c384f94 CR3: 000000000df36000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
__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+0x6b1/0x12d0 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
free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
exit_mmap+0x17c/0xb50 mm/mmap.c:1266
__mmput+0x118/0x420 kernel/fork.c:1130
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
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:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f76eaf8eb69
Code: Unable to access opcode bytes at 0x7f76eaf8eb3f.
RSP: 002b:00007f76e8df6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffe00 RBX: 00007f76eb1b5fa0 RCX: 00007f76eaf8eb69
RDX: 0000200000000080 RSI: 0000200000000300 RDI: 0000000000000000
RBP: 00007f76eb011df1 R08: 0000200000000240 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f76eb1b5fa0 R15: 00007fff4b5fc4e8