==================================================================
BUG: KASAN: stack-out-of-bounds in deref_stack_regs arch/x86/kernel/unwind_orc.c:311 [inline]
BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x1424/0x1700 arch/x86/kernel/unwind_orc.c:441
Read of size 8 at addr ffff8880906ef8d8 by task systemd-udevd/3638

CPU: 0 PID: 3638 Comm: systemd-udevd Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393
 deref_stack_regs arch/x86/kernel/unwind_orc.c:311 [inline]
 unwind_next_frame+0x1424/0x1700 arch/x86/kernel/unwind_orc.c:441
 __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcb/0x260 mm/slab.c:3815
 __rcu_reclaim kernel/rcu/rcu.h:195 [inline]
 rcu_do_batch kernel/rcu/tree.c:2699 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
 rcu_process_callbacks+0x78d/0x1180 kernel/rcu/tree.c:2946
 __do_softirq+0x254/0x9bf kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x15b/0x1a0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x141/0x5f0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793
 </IRQ>
RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:774 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:796 [inline]
RIP: 0010:lock_is_held_type+0x81/0x210 kernel/locking/lockdep.c:4032
RSP: 0018:ffff8880906ef748 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0f62cd0 RBX: ffff8880906e26c0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 00000000ffffffff RDI: ffff8880906e2f44
RBP: ffffffff87b84b60 R08: 0000000000000001 R09: 0000000000000001
R10: ffffed10120ddf05 R11: ffff8880906ef82f R12: ffffffff82c75454
R13: ffff8880906ef8c0 R14: 000000000000001d R15: 0000000000000000
 security_context_to_sid_core+0x284/0x3d0 security/selinux/ss/services.c:1460
 retint_kernel+0x2d/0x2d
RIP: 87ed0750:timespec_trunc+0xcf/0x120
RSP: 9a9efcc0:000000000000001d EFLAGS: ffff8880a6ff4a30 ORIG_RAX: ffffffffffffff10
RAX: ffffffff87734dbf RBX: ffff88809a0c6c80 RCX: ffffffff82c36240
RDX: 1ffff110120ddf26 RSI: 0000000000000029 RDI: ffff8880906ef930
RBP: 000000000000001d R08: 0000000041b58ab3 R09: ffffffff86bd78e0
R10: ffffffff82c36395 R11: ffff88809a9ba900 R12: ffff88809a9efcc0
R13: 1ffff110120ddf14 R14: ffff8880a6ff4a30 R15: ffff8880a8af27a1

The buggy address belongs to the page:
page:ffffea000241bbc0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0xfffe0000000000()
raw: 00fffe0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: ffffea000241bbe0 ffffea000241bbe0 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880906ef780: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 f1 f1 00 00
 ffff8880906ef800: 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00
>ffff8880906ef880: 00 00 00 00 f1 f1 f1 f1 04 f3 f3 f3 00 00 00 00
                                                    ^
 ffff8880906ef900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880906ef980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================