rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (2 ticks this GP) idle=ec64/1/0x4000000000000000 softirq=16405/16405 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=8557, q=1114 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6200 Comm: syz.1.81 Not tainted 6.16.0-rc6-syzkaller-00128-g81e0db8e8398-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__lock_acquire+0x893/0xd20
Code: 83 3d b4 c0 03 0e 00 0f 85 36 02 00 00 48 83 7c 24 28 00 0f 84 bc 01 00 00 41 8b 46 f8 25 ff 1f 00 00 48 0f a3 05 dd 3b 09 12 <0f> 83 5a 01 00 00 48 69 c0 c8 00 00 00 48 8d 80 f0 82 48 93 e9 87
RSP: 0018:ffffc90000007b70 EFLAGS: 00000003
RAX: 000000000000001a RBX: 0000000000000004 RCX: 0000000090213bdc
RDX: 00000000001a71fd RSI: 00000000727d5714 RDI: ffff888108b99cc0
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81ae7b72
R10: dffffc0000000000 R11: fffffbfff1f43adf R12: 0000000000000068
R13: ffff888108b9a7b0 R14: ffff888108b9a850 R15: d6bf87c490213bdc
FS:  0000555557237500(0000) GS:ffff8880b8623000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b0b9f1fe08 CR3: 000000000df38000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lock_acquire+0x120/0x360
 _raw_spin_lock_irq+0xa2/0xf0
 __hrtimer_run_queues+0x602/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:debug_lockdep_rcu_enabled+0x2d/0x40
Code: fa 31 c0 83 3d 17 48 34 04 00 74 1e 83 3d 3a 78 34 04 00 74 15 65 48 8b 0c 25 08 d0 9f 92 31 c0 83 b9 ec 0a 00 00 00 0f 94 c0 <e9> 8e d3 02 00 cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90
RSP: 0018:ffffc900062ff310 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffff822d71ea RCX: ffff888108b99cc0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822d71ea
R10: dffffc0000000000 R11: fffff940008a4d19 R12: dffffc0000000000
R13: 0000000000000008 R14: 00000000001149a3 R15: ffff88805fffa840
 pfn_valid+0x32a/0x490
 page_table_check_clear+0x21/0x700
 unmap_page_range+0x3249/0x41c0
 unmap_vmas+0x399/0x580
 exit_mmap+0x248/0xb50
 __mmput+0x118/0x420
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x22e0
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fae8878e9a9
Code: Unable to access opcode bytes at 0x7fae8878e97f.
RSP: 002b:00007ffccceca1e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 0000000000010048 RCX: 00007fae8878e9a9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fae889b608c
RBP: 0000000000000032 R08: 7fffffffffffffff R09: 0000001dcceca4df
R10: 00007ffccceca2e0 R11: 0000000000000246 R12: 00007fae889b608c
R13: 00007ffccceca2e0 R14: 000000000001007a R15: 00007ffccceca300
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g8557 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=2482
rcu: rcu_preempt kthread starved for 10502 jiffies! g8557 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27128 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x16f5/0x4d00
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
