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BUG: KASAN: stack-out-of-bounds in deref_stack_reg+0x1b8/0x1d0
Read of size 8 at addr ffff8801d573fa00 by task syz-executor6/5530

CPU: 0 PID: 5530 Comm: syz-executor6 Not tainted 4.14.0-rc5-mm1+ #17
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 dump_stack+0x173/0x237
 print_address_description+0x6e/0x250
 kasan_report+0x251/0x340
 deref_stack_reg+0x1b8/0x1d0
 unwind_next_frame+0xebc/0x1df0
 __save_stack_trace+0x6e/0xd0
 save_stack+0x32/0xb0
 kasan_slab_free+0x71/0xc0
 kmem_cache_free+0x72/0x280
 rcu_process_callbacks+0xcd4/0x1600
 __do_softirq+0x2ba/0xafb
 irq_exit+0x1c7/0x200
 smp_apic_timer_interrupt+0x154/0x6b0
 apic_timer_interrupt+0x96/0xa0
 </IRQ>
RIP: 0010:lock_is_held_type+0x84/0x200
RSP: 0018:ffff8801d573f860 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff11
RAX: dffffc0000000000 RBX: ffff8801d5d5c5c0 RCX: 0000000000000000
RDX: 1ffffffff0ad8f48 RSI: 00000000ffffffff RDI: ffffffff856c7a40
RBP: 0000000000000148 R08: 0000000000000002 R09: 00000000ac0926c5
R10: 000000007fecb88c R11: 0000000000000000 R12: ffffffff85737ce0
R13: 0000000000000188 R14: 00000000014080c0 R15: ffff8801c47191c8
 taskstats_exit+0x715/0xe00

The buggy address belongs to the page:
page:ffffea000755cfc0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x200000000000000()
raw: 0200000000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d573f900: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f2 f2
 ffff8801d573f980: f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 f2 f2 f8 f2 f2
>ffff8801d573fa00: f2 f2 f2 f2 f2 00 f2 f2 f2 f3 f3 f3 f3 00 00 00
                   ^
 ffff8801d573fa80: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2
 ffff8801d573fb00: f2 f2 f2 f2 f2 f2 04 f2 f2 f2 f2 f2 f2 f2 00 f2
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