rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 ticks this GP) idle=fd04/1/0x4000000000000000 softirq=17368/17369 fqs=0
rcu: 	(t=29914 jiffies g=12357 q=55 ncpus=2)
rcu: rcu_preempt kthread starved for 29914 jiffies! g12357 f0x0 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:27536 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 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: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:io_serial_in+0x77/0xc0
Code: e8 6e ff 80 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf 3a ec fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 9a 7a 66 06 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001169b8 EFLAGS: 00000006
RAX: 1ffffffff34f3f05 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffc90000116b50 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8544bc80 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff9a79f840 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88818dc90000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000011435f000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 serial8250_console_write+0x540/0x1ba0
 console_flush_all+0x718/0xb20
 console_unlock+0xd1/0x1c0
 vprintk_emit+0x485/0x560
 _printk+0xdd/0x130
 show_ip+0x27/0x40
 show_iret_regs+0x12/0x40
 __show_regs+0x34/0x600
 __show_trace_log_lvl+0x38f/0x550
 __die_body+0xa4/0xb0
 die_addr+0x4a/0x70
 exc_general_protection+0x156/0x1f0
 asm_exc_general_protection+0x26/0x30
RIP: 0010:pick_next_entity+0xca8/0xe90
Code: 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 5d e8 97 00 4c 3b 33 79 05 48 8b 6c 24 40 48 8d 5d 59 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 75 61 80 3b 00 74 14 48 8b 7c 24 70 48 89 ee
RSP: 0018:ffffc90000117250 EFLAGS: 00010002
RAX: 000000000000000b RBX: 0000000000000059 RCX: 1ffff110242075e6
RDX: 1ffff110242075e4 RSI: ffff88812103af00 RDI: ffff88812103af20
RBP: 0000000000000000 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe
R10: dffffc0000000000 R11: fffffbfff20614ff R12: dffffc0000000000
R13: ffff88812103af20 R14: 0000000000000000 R15: 0000000000000000
 pick_task_fair+0xca/0x260
 pick_next_task_fair+0x173/0x1ab0
 __pick_next_task+0xe6/0x480
 __schedule+0x974/0x5680
 preempt_schedule_irq+0x4d/0xa0
 irqentry_exit+0x14f/0x730
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x221/0x350
Code: ff ff ff e8 21 95 06 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 0b 50 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 18 4e 92
RSP: 0018:ffffc900001178a0 EFLAGS: 00000286
RAX: 84da12799a781200 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000e98c4b04 RSI: ffffffff8e2189dd RDI: ffffffff8c28ac60
RBP: ffffffff8b6f6c1a R08: ffffffff8b6f6c1a R09: ffffffff8e95cd60
R10: dffffc0000000000 R11: ffffed10042bfb17 R12: 0000000000000002
R13: ffffffff8e95cd60 R14: 0000000000000000 R15: 0000000000000246
 batadv_iv_ogm_schedule+0x45e/0xf50
 batadv_iv_send_outstanding_bat_ogm_packet+0x6c8/0x7e0
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
CPU: 1 UID: 0 PID: 6110 Comm: syz.1.95 Not tainted syzkaller #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:vcpu_run+0x5a02/0x7860
Code: 4c 8b a4 24 28 01 00 00 4c 89 e3 48 c1 eb 03 42 0f b6 04 3b 84 c0 0f 85 1c 0b 00 00 41 c6 04 24 01 e8 a2 eb 85 00 fb 4c 89 f0 <48> c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 9b fb e8 00 49 ff 06
RSP: 0018:ffffc90007e075e0 EFLAGS: 00000202
RAX: ffff8880229f9d60 RBX: 1ffff1100453f187 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8dfa5a5d RDI: ffffffff8c28ac60
RBP: ffffc90007e079b0 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe
R10: dffffc0000000000 R11: fffffbfff20614ff R12: ffff8880229f8c3a
R13: ffff8880229f8000 R14: ffff8880229f9d60 R15: dffffc0000000000
FS:  00007f2a482086c0(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000105f52000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 kvm_arch_vcpu_ioctl_run+0x11e6/0x20d0
 kvm_vcpu_ioctl+0xa62/0xfd0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2a4739cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2a48208028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2a47615fa0 RCX: 00007f2a4739cdd9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000008
RBP: 00007f2a47432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2a47616038 R14: 00007f2a47615fa0 R15: 00007ffe44e97108
 </TASK>
