rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=7734/1/0x4000000000000000 softirq=266612/266612 fqs=2
rcu: 	(detected by 1, t=14062 jiffies, g=199965, q=266 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 101 PID: 5344 Comm: dhcpcd 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:lock_release+0x3a/0x3c0
Code: ec 30 49 89 f5 49 89 fe 65 48 8b 05 20 11 97 11 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 23 11 97 11 83 f8 08 0f 83 56 02 00 00 <89> c0 48 0f a3 05 cc b8 8e 0e 73 0d e8 45 f7 08 00 84 c0 0f 84 94
RSP: 0018:ffffc900000073d0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffffff90f62201 RCX: 0000000000000103
RDX: ffffc90000007501 RSI: ffffffff81770256 RDI: ffffffff8e95cd60
RBP: dffffc0000000000 R08: ffffc900032e7ea8 R09: 0000000000000000
R10: ffffc90000007558 R11: fffff52000000ead R12: ffffc900032e7eb8
R13: ffffffff81770256 R14: ffffffff8e95cd60 R15: ffffffff81770256
FS:  00007f8b49452740(0000) GS:ffff88818dc90000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000116263000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 unwind_next_frame+0x1bba/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x35c/0x760
 switchdev_deferred_enqueue+0x2d/0x240
 switchdev_port_obj_del+0x1e0/0x2f0
 br_switchdev_mdb_notify+0x288/0x480
 __br_mdb_notify+0x73/0x970
 br_multicast_group_expired+0x2f7/0x3c0
 call_timer_fn+0x192/0x5e0
 __run_timer_base+0x652/0x8b0
 run_timer_softirq+0xb7/0x170
 handle_softirqs+0x22a/0x840
 __irq_exit_rcu+0xca/0x220
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0xa6/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80
Code: f7 e8 dd 64 f7 f5 f7 c3 00 02 00 00 74 05 e8 80 f8 22 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 54 e7 e8 f5 65 8b 05 ed 00 8e 07 85 c0 74 18 5b 41 5e e9 51 48
RSP: 0018:ffffc900032e7a58 EFLAGS: 00000206
RAX: 0000000000000002 RBX: 0000000000000282 RCX: 0000000080000001
RDX: 0000000000000007 RSI: ffffffff8dfa5c57 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe
R10: dffffc0000000000 R11: fffffbfff20614ff R12: ffff88810a3b5000
R13: ffff88810a3b4000 R14: ffffffff9a6c1698 R15: 0000000000000001
 debug_check_no_obj_freed+0x52e/0x550
 kfree+0x13e/0x640
 tomoyo_realpath_from_path+0x598/0x5d0
 tomoyo_path_number_perm+0x246/0x630
 security_file_ioctl+0xc3/0x2a0
 __se_sys_ioctl+0x47/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b49520d49
Code: 5c c3 48 8d 44 24 08 48 89 54 24 e0 48 89 44 24 c0 48 8d 44 24 d0 48 89 44 24 c8 b8 10 00 00 00 c7 44 24 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 76 10 48 8b 15 ae 60 0d 00 f7 d8 41 83 c8
RSP: 002b:00007fff74c821f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000555e5903c250 RCX: 00007f8b49520d49
RDX: 00007fff74c82200 RSI: 0000000000008921 RDI: 0000000000000011
RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000036
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff74c82200
R13: 0000555e57e30f88 R14: 0000555e5903c250 R15: 0000555e58fa57b0
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 14057 jiffies! g199965 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=47565
rcu: rcu_preempt kthread starved for 14058 jiffies! g199965 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->cpu=1
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 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:
CPU: 1 UID: 0 PID: 29703 Comm: syz.2.4991 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 fb 85 00 fb 4c 89 f0 <48> c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 9b 0b e9 00 49 ff 06
RSP: 0018:ffffc9000bd3f5e0 EFLAGS: 00000202
RAX: ffff88816fb49d60 RBX: 1ffff1102df69187 RCX: 0000000000000001
RDX: 0000000000000006 RSI: ffffffff8dfa5c57 RDI: ffffffff8c28ac60
RBP: ffffc9000bd3f9b0 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe
R10: dffffc0000000000 R11: fffffbfff20614ff R12: ffff88816fb48c3a
R13: ffff88816fb48000 R14: ffff88816fb49d60 R15: dffffc0000000000
FS:  00007f06475ae6c0(0000) GS:ffff8882a9290000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000016aef1000 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: 0033:0x7f064679cdd9
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:00007f06475ae028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0646a15fa0 RCX: 00007f064679cdd9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 00007f0646832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0646a16038 R14: 00007f0646a15fa0 R15: 00007ffcc382a6f8
 </TASK>
