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BUG: KASAN: stack-out-of-bounds in deref_stack_regs arch/x86/kernel/unwind_orc.c:305 [inline]
BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x142e/0x17d0 arch/x86/kernel/unwind_orc.c:437
Read of size 8 at addr ffff88808dc67c18 by task syz-executor.3/13280

CPU: 1 PID: 13280 Comm: syz-executor.3 Not tainted 4.14.232-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+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 deref_stack_regs arch/x86/kernel/unwind_orc.c:305 [inline]
 unwind_next_frame+0x142e/0x17d0 arch/x86/kernel/unwind_orc.c:437
 __save_stack_trace+0x90/0x160 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+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 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+0x780/0x1180 kernel/rcu/tree.c:2946
 __do_softirq+0x24d/0x9ff kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x193/0x240 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:638 [inline]
 smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106
 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_acquire+0x97/0x3f0 kernel/locking/lockdep.c:3993
RSP: 0018:ffff88808dc67af0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff11e1258 RBX: ffff88809f0a64c0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff88809f0a6d44
RBP: ffff8880aaab2860 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88809f0a64c0 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 perf_event_ctx_lock_nested+0x14d/0x2c0 kernel/events/core.c:1241
 retint_kernel+0x2d/0x2d
RIP: 0003:0xffff88809f0a64c0
RSP: 9f0a6d40:0000000000000286 EFLAGS: 00000286 ORIG_RAX: ffffffff8bebbd40
RAX: ffff88823fff704f RBX: ffff88809f0a64c0 RCX: 0000000041b58ab3
RDX: 1ffff11011b8cf86 RSI: ffffffff88f77800 RDI: ffffffff816334b7
RBP: ffffffff8bebbd40 R08: ffff88809f0a6d40 R09: ffffffff87220490
R10: ffffffff88b59578 R11: 0000000041b58ab3 R12: ffffffff816334ed
R13: ffff8880aaab2860 R14: 1ffff11011b8cf7b R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea00023719c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0xfff00000000000()
raw: 00fff00000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808dc67b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808dc67b80: 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 f2 00 00
>ffff88808dc67c00: 00 f2 f2 f2 00 00 00 00 00 f3 f3 f3 f3 f3 00 00
                            ^
 ffff88808dc67c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808dc67d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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