rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=58745, q=355 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294988111-4294977609), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g58745 f0x2 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:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 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+0x70e/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
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9566 Comm: syz-executor Not tainted 6.16.0-rc1-syzkaller-00203-g4774cfe3543a #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:debug_object_deactivate+0x0/0x250 lib/debugobjects.c:862
Code: 8c 49 ff ff ff e8 e0 1f 61 fd e9 3f ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 38 48 89 f3 49
RSP: 0018:ffffc90000007d10 EFLAGS: 00000006
RAX: ffffffff81ae930e RBX: ffff888058b21340 RCX: ffff88802d6f5a00
RDX: 0000000000010000 RSI: ffffffff8b8cf340 RDI: ffff888058b21340
RBP: ffffc90000007e90 R08: ffff888058b21357 R09: 0000000000000000
R10: ffff888058b21340 R11: ffffed100b16426b R12: ffff888058b21340
R13: dffffc0000000000 R14: 185282d8c8000000 R15: ffff8880b8627cc0
FS:  000055555960f500(0000) GS:ffff888125c86000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555559632608 CR3: 000000007774a000 CR4: 00000000003526f0
DR0: 0000040000000000 DR1: 000000000000064f DR2: 0000000000000006
DR3: 0000000000000006 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 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+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:preempt_count_add+0x126/0x1a0 kernel/sched/core.c:5866
Code: 48 c7 c7 e0 3e 8a 8b 48 c7 c6 20 3f 8a 8b e8 a1 33 f3 ff 90 0f 0b 90 90 90 89 df e9 58 ff ff ff 48 c7 c1 20 f3 a4 99 80 e1 07 <80> c1 03 38 c1 0f 8c fa fe ff ff 89 fb 48 c7 c7 20 f3 a4 99 e8 01
RSP: 0018:ffffc9000e3bfa18 EFLAGS: 00000246
RAX: 0000000000000004 RBX: ffff888078119b28 RCX: ffffffff99a4f300
RDX: ffff88802d6f5a00 RSI: 00000000ffffffff RDI: 0000000000000001
RBP: 00000000ffffffff R08: 0000000000000000 R09: ffffffff82383ec7
R10: dffffc0000000000 R11: ffffed100f0170a5 R12: dffffc0000000000
R13: ffff8880780b8468 R14: ffff888078119a70 R15: dffffc0000000000
 __raw_spin_lock include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock+0x12/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 fast_dput+0xdd/0x430 fs/dcache.c:827
 dput+0xe8/0x2b0 fs/dcache.c:905
 step_into+0x34d/0xf30 fs/namei.c:1991
 lookup_last fs/namei.c:2639 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2663
 filename_lookup+0x212/0x570 fs/namei.c:2692
 user_path_at+0x3a/0x60 fs/namei.c:3127
 ksys_umount fs/namespace.c:2147 [inline]
 __do_sys_umount fs/namespace.c:2155 [inline]
 __se_sys_umount fs/namespace.c:2153 [inline]
 __x64_sys_umount+0xee/0x160 fs/namespace.c:2153
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fac7a38fc57
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffcaad42278 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fac7a38fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcaad42330
RBP: 00007ffcaad42330 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcaad433c0
R13: 00007fac7a410925 R14: 0000000000062dbc R15: 00007ffcaad43400
 </TASK>