syzbot

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=521/1/0x4000000000000000 softirq=228112/228113 fqs=4721 
	(t=10500 jiffies g=366705 q=330)
NMI backtrace for cpu 1
CPU: 1 PID: 22814 Comm: syz-executor.4 Not tainted 5.17.0-rc2-syzkaller-00353-g90c9e950c0de #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:688 [inline]
 rcu_pending kernel/rcu/tree.c:3919 [inline]
 rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2617
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__local_bh_enable_ip+0xa8/0x120 kernel/softirq.c:390
Code: 1d 5d 04 bc 7e 65 8b 05 56 04 bc 7e a9 00 ff ff 00 74 45 bf 01 00 00 00 e8 75 41 09 00 e8 60 88 37 00 fb 65 8b 05 38 04 bc 7e <85> c0 74 58 5b 5d c3 65 8b 05 86 0b bc 7e 85 c0 75 a2 0f 0b eb 9e
RSP: 0018:ffffc900046b7830 EFLAGS: 00000206
RAX: 0000000000000201 RBX: 00000000fffffe00 RCX: 1ffffffff20042be
RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000
RBP: ffffffff88e8e885 R08: 0000000000000001 R09: ffffffff8ffc3a3f
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000100
R13: ffff88807d93aa18 R14: 000000000000033d R15: dffffc0000000000
 spin_unlock_bh include/linux/spinlock.h:394 [inline]
 batadv_tt_local_purge+0x285/0x370 net/batman-adv/translation-table.c:1357
 batadv_tt_local_resize_to_mtu+0x8e/0x130 net/batman-adv/translation-table.c:3957
 batadv_update_min_mtu net/batman-adv/hard-interface.c:624 [inline]
 batadv_hard_if_event+0x67d/0x1610 net/batman-adv/hard-interface.c:957
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1919
 call_netdevice_notifiers_mtu net/core/dev.c:1968 [inline]
 dev_set_mtu_ext+0x39d/0x5b0 net/core/dev.c:8281
 dev_set_mtu+0x8e/0x120 net/core/dev.c:8302
 dev_ifsioc+0xb87/0x1120 net/core/dev_ioctl.c:332
 dev_ioctl+0x1b9/0xed0 net/core/dev_ioctl.c:586
 sock_do_ioctl+0x15a/0x230 net/socket.c:1136
 sock_ioctl+0x2f1/0x640 net/socket.c:1239
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f709d80a059
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f709c17f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f709d91cf60 RCX: 00007f709d80a059
RDX: 00000000200000c0 RSI: 0000000000008922 RDI: 0000000000000003
RBP: 00007f709d86408d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffa5ba5b5f R14: 00007f709c17f300 R15: 0000000000022000
 </TASK>
vkms_vblank_simulate: vblank timer overrun
----------------
Code disassembly (best guess):
   0:	1d 5d 04 bc 7e       	sbb    $0x7ebc045d,%eax
   5:	65 8b 05 56 04 bc 7e 	mov    %gs:0x7ebc0456(%rip),%eax        # 0x7ebc0462
   c:	a9 00 ff ff 00       	test   $0xffff00,%eax
  11:	74 45                	je     0x58
  13:	bf 01 00 00 00       	mov    $0x1,%edi
  18:	e8 75 41 09 00       	callq  0x94192
  1d:	e8 60 88 37 00       	callq  0x378882
  22:	fb                   	sti
  23:	65 8b 05 38 04 bc 7e 	mov    %gs:0x7ebc0438(%rip),%eax        # 0x7ebc0462
* 2a:	85 c0                	test   %eax,%eax <-- trapping instruction
  2c:	74 58                	je     0x86
  2e:	5b                   	pop    %rbx
  2f:	5d                   	pop    %rbp
  30:	c3                   	retq
  31:	65 8b 05 86 0b bc 7e 	mov    %gs:0x7ebc0b86(%rip),%eax        # 0x7ebc0bbe
  38:	85 c0                	test   %eax,%eax
  3a:	75 a2                	jne    0xffffffde
  3c:	0f 0b                	ud2
  3e:	eb 9e                	jmp    0xffffffde