rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10500 ticks this GP) idle=0c0c/1/0x4000000000000000 softirq=225760/225761 fqs=0
rcu: 	(t=10501 jiffies g=215909 q=329 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g215909 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=99971
rcu: rcu_preempt kthread starved for 10501 jiffies! g215909 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:27488 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_timeout+0x152/0x2c0
 rcu_gp_fqs_loop+0x30c/0x11f0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </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: 9877 Comm: kworker/0:6 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: events delayed_vfree_work
RIP: 0010:debug_object_activate+0xb7/0x420
Code: 0f af c8 48 c1 e9 2f 83 e1 f8 48 8d 2c c9 48 81 c5 a0 0a 96 9a 48 8d 3c c9 48 81 c7 a8 0a 96 9a 48 89 7c 24 08 e8 69 e1 f2 06 <48> 89 04 24 48 89 e8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 ef e8
RSP: 0018:ffffc90000007b98 EFLAGS: 00000046
RAX: 0000000000000086 RBX: ffff888112601300 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007b00
RBP: ffffffff9aa362b0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f60 R12: 0000000000000001
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88818d95c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c338790 CR3: 0000000112174000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 enqueue_hrtimer+0xa9/0x2c0
 __hrtimer_run_queues+0x4ce/0xa10
 hrtimer_interrupt+0x448/0x910
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:handle_softirqs+0x15b/0x840
Code: 89 6c 24 20 0f b7 db 48 c7 c7 60 30 eb 8b e8 2c 38 47 0a 65 66 c7 05 3a d5 e3 11 00 00 e8 cd b9 46 00 fb 48 c7 c5 c0 a0 80 8e <b8> ff ff ff ff 0f bc c3 41 89 c4 41 ff c4 0f 84 09 04 00 00 89 5c
RSP: 0018:ffffc90000007f30 EFLAGS: 00000202
RAX: 00000000000195f8 RBX: 000000000000000c RCX: 0000000080000100
RDX: 0000000000000002 RSI: ffffffff8e226e28 RDI: ffffffff8c4bc580
RBP: ffffffff8e80a0c0 R08: ffffffff90572537 R09: 1ffffffff20ae4a6
R10: dffffc0000000000 R11: fffffbfff20ae4a7 R12: 0000000000000000
R13: 0000000000000000 R14: ffff888117683c00 R15: dffffc0000000000
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 common_interrupt+0xbb/0xe0
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40
RIP: 0010:lock_acquire+0x231/0x350
Code: ff ff ff e8 91 e6 2c 0a f7 44 24 10 00 02 00 00 0f 84 39 ff ff ff 65 48 8b 05 7b a1 c9 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d e8 14 b8
RSP: 0018:ffffc90021e6f5a0 EFLAGS: 00000296
RAX: 3fa1e24169c9ef00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000495aa5ed RSI: ffffffff8e4ab857 RDI: ffffffff8c4bc580
RBP: ffff888117683c00 R08: 1e00000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: ffffffff8eb59c60
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000246
 unwind_next_frame+0xac/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x40/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c5/0x640
 vfree+0x429/0x490
 delayed_vfree_work+0x55/0x80
 process_scheduled_works+0xa8e/0x14e0
 worker_thread+0xa47/0xfb0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
CPU: 1 UID: 0 PID: 11488 Comm: syz.0.12287 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:smp_call_function_many_cond+0x11eb/0x15f0
Code: 1e 89 de 83 e6 01 31 ff e8 42 21 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 ee 1c 0c 00 eb 37 f3 90 41 0f b6 04 1c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 d3 1c 0c 00 eb e5 44 89
RSP: 0018:ffffc90006567440 EFLAGS: 00000293
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888111e91e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90006567588 R08: ffffffff90572537 R09: 1ffffffff20ae4a6
R10: dffffc0000000000 R11: fffffbfff20ae4a7 R12: 1ffff11024208611
R13: ffff88823c63c448 R14: ffff888121043088 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a8f5c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3b2d68 CR3: 000000000e946000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80
 flush_tlb_mm_range+0x5c4/0x1090
 tlb_flush_mmu+0x1af/0xa30
 tlb_finish_mmu+0xf4/0x220
 free_ldt_pgtables+0x192/0x360
 exit_mmap+0x1bf/0x9f0
 __mmput+0x118/0x420
 exit_mm+0x221/0x2d0
 do_exit+0x6cd/0x2360
 do_group_exit+0x22d/0x2f0
 get_signal+0x121b/0x12c0
 arch_do_signal_or_restart+0xbb/0x860
 exit_to_user_mode_loop+0x104/0x730
 do_syscall_64+0x353/0x580
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efe52f9e0d9
Code: Unable to access opcode bytes at 0x7efe52f9e0af.
RSP: 002b:00007efe53e4f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007efe53225fa8 RCX: 00007efe52f9e0d9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007efe53225fac
RBP: 00007efe53225fa0 R08: 3fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007efe53226038 R14: 00007ffc1a82cb90 R15: 00007ffc1a82cc78
 </TASK>
