rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11998/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=54893, q=547 ncpus=2)
task:syz.6.1462 state:R running task stack:24160 pid:11998 tgid:11997 ppid:6457 task_flags:0x40054c flags:0x00004006
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_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
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 3b 06 02 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:ffffc9000d356ab8 EFLAGS: 00000206
RAX: ea55a0310fc85f00 RBX: 0000000000000000 RCX: ea55a0310fc85f00
RDX: 0000000000000000 RSI: ffffffff8dba0269 RDI: ffffffff8be2fd00
RBP: ffffffff8172c025 R08: 0000000000000000 R09: ffffffff8172c025
R10: dffffc0000000000 R11: ffffffff81ac34b0 R12: 0000000000000002
R13: ffffffff8e139e60 R14: 0000000000000000 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf5/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
free_unref_folios+0xdbd/0x1520 mm/page_alloc.c:2952
folios_put_refs+0x559/0x640 mm/swap.c:997
free_pages_and_swap_cache+0x4be/0x520 mm/swap_state.c:267
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
zap_pte_range mm/memory.c:1765 [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+0x3b31/0x4370 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+0x118/0x430 kernel/fork.c:1127
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
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: 0033:0x7f421ed8d7ca
RSP: 002b:00007f421fbc3e50 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: ffffffffffffffff RCX: 00007f421ed8d7ca
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000016
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000016
R13: 00007f421fbc3eb0 R14: 00000000000059ec R15: 0000200000000040
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g54893 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=1 timer-softirq=39029
rcu: rcu_preempt kthread starved for 10500 jiffies! g54893 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27224 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+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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted 6.16.0-syzkaller-11241-g186f3edfdd41 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_release+0x89/0x3e0 kernel/locking/lockdep.c:5881
Code: ec 05 0e 00 0f 84 44 02 00 00 65 8b 05 20 36 02 11 85 c0 0f 85 35 02 00 00 65 4c 8b 3c 25 08 60 9f 92 41 83 bf ec 0a 00 00 00 <0f> 85 1e 02 00 00 49 81 3e 40 23 63 93 0f 84 11 02 00 00 48 c7 44
RSP: 0018:ffffc90000a08658 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000012 RCX: 8a37408b48ae0c00
RDX: 0000000000000001 RSI: ffffffff8be2fce0 RDI: ffffffff8be2fca0
RBP: ffffc90000a08748 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001410b8 R12: dffffc0000000000
R13: ffffffff81ade22d R14: ffffffff99ccd9f0 R15: ffff88801d6b5a00
FS: 0000000000000000(0000) GS:ffff888125d2a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3de1cb CR3: 000000009b3bd000 CR4: 0000000000350ef0
Call Trace:
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
_raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194
debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline]
debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:490
__run_hrtimer kernel/time/hrtimer.c:1729 [inline]
__hrtimer_run_queues+0x2b0/0xc60 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+0x52/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:note_gp_changes+0x25f/0x300 kernel/rcu/tree.c:1340
Code: 20 00 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 f6 44 24 41 02 75 4f 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 20 0e 36 e0 45 <4a> c7 04 2b 00 00 00 00 66 42 c7 44 2b 09 00 00 42 c6 44 2b 0b 00
RSP: 0018:ffffc90000a08b00 EFLAGS: 00000206
RAX: 8a37408b48ae0c00 RBX: 1ffff92000141164 RCX: 8a37408b48ae0c00
RDX: 0000000000000002 RSI: ffffffff8d9b1663 RDI: ffffffff8be2fd00
RBP: ffffc90000a08bd0 R08: ffffffff8fa32537 R09: 1ffffffff1f464a6
R10: dffffc0000000000 R11: fffffbfff1f464a7 R12: ffff8880b873af94
R13: dffffc0000000000 R14: 0000000000000212 R15: ffff8880b873af80
rcu_check_quiescent_state kernel/rcu/tree.c:2489 [inline]
rcu_core+0x2a0/0x1770 kernel/rcu/tree.c:2845
handle_softirqs+0x286/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_call_function_single arch/x86/kernel/smp.c:266 [inline]
sysvec_call_function_single+0xa3/0xc0 arch/x86/kernel/smp.c:266
asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 cb 45 4d f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 53 04 16 f6 65 8b 05 1c 6a 25 07 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90000ac76e0 EFLAGS: 00000206
RAX: 8a37408b48ae0c00 RBX: 0000000000000246 RCX: 8a37408b48ae0c00
RDX: 0000000000000006 RSI: ffffffff8d9b1663 RDI: 0000000000000001
RBP: ffffc90000ac7770 R08: ffffffff8fa32537 R09: 1ffffffff1f464a6
R10: dffffc0000000000 R11: fffffbfff1f464a7 R12: dffffc0000000000
R13: ffffffff8e13f180 R14: ffffffff8e13f180 R15: 1ffff92000158edc
rcu_preempt_deferred_qs_irqrestore+0x89c/0xce0 kernel/rcu/tree_plugin.h:-1
rcu_read_unlock_special+0x475/0x5e0 kernel/rcu/tree_plugin.h:775
__rcu_read_unlock+0x84/0xe0 kernel/rcu/tree_plugin.h:438
rcu_read_unlock include/linux/rcupdate.h:873 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
batadv_nc_worker+0x291/0x610 net/batman-adv/network-coding.c:719
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
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