rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10503 jiffies, g=41381, q=32 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294990075-4294979572), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10503 jiffies! g41381 f0x2 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:27192 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
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: 1 UID: 0 PID: 10430 Comm: syz.3.1119 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:queued_write_lock_slowpath+0x120/0x260 kernel/locking/qrwlock.c:85
Code: a8 f6 f0 81 0b 00 01 00 00 43 0f b6 04 27 84 c0 74 35 89 d9 80 e1 07 80 c1 03 38 c1 7c 29 48 89 df e8 44 27 a8 f6 eb 1f f3 90 <43> 0f b6 04 27 84 c0 74 14 89 d9 80 e1 07 80 c1 03 38 c1 7c 08 48
RSP: 0018:ffffc90000a08500 EFLAGS: 00000206
RAX: 00000000000001ff RBX: ffffffff8f636b00 RCX: ffffffff8b7ad988
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8f636b00
RBP: ffffc90000a085b0 R08: ffffffff8f636b03 R09: 1ffffffff1ec6d60
R10: dffffc0000000000 R11: fffffbfff1ec6d61 R12: dffffc0000000000
R13: 1ffff920001410a4 R14: ffffc90000a08550 R15: 1ffffffff1ec6d60
FS: 0000000000000000(0000) GS:ffff888125ce3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f00642bd493 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
queued_write_lock include/asm-generic/qrwlock.h:101 [inline]
do_raw_write_lock+0x1f2/0x260 kernel/locking/spinlock_debug.c:211
___neigh_create+0xe81/0x2260 net/core/neighbour.c:656
ip6_finish_output2+0xb4d/0x16a0 net/ipv6/ip6_output.c:132
NF_HOOK include/linux/netfilter.h:317 [inline]
ndisc_send_skb+0xb54/0x1440 net/ipv6/ndisc.c:512
addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4032
call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
expire_timers kernel/time/timer.c:1798 [inline]
__run_timers kernel/time/timer.c:2372 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
run_timer_base kernel/time/timer.c:2393 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
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_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:869
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 46 5a 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 f1 55 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 d5 55
RSP: 0018:ffffc90002f27340 EFLAGS: 00000293
RAX: ffffffff81b45b3b RBX: 1ffff110170c8341 RCX: ffff88804d6f9e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002f274c0 R08: ffffffff8fa2a737 R09: 1ffffffff1f454e6
R10: dffffc0000000000 R11: fffffbfff1f454e7 R12: ffff8880b8641a08
R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1036
__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+0x118/0x430 kernel/fork.c:1124
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x648/0x2300 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
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:208 [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: 0033:0x7f3d6858e9a9
Code: Unable to access opcode bytes at 0x7f3d6858e97f.
RSP: 002b:00007ffc911bbe28 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffff92 RBX: 0000000000067730 RCX: 00007f3d6858e9a9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3d687b608c
RBP: 0000000000000bea R08: 7fffffffffffffff R09: 00000005911bc11f
R10: 00007ffc911bbf20 R11: 0000000000000246 R12: 00007f3d687b608c
R13: 00007ffc911bbf20 R14: 000000000006831a R15: 00007ffc911bbf40