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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+0x146f/0x17d0 arch/x86/kernel/unwind_orc.c:444
Read of size 8 at addr ffff8880a795fcb0 by task syz-executor005/16819

CPU: 1 PID: 16819 Comm: syz-executor005 Not tainted 4.14.195-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+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 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:311 [inline]
 unwind_next_frame+0x146f/0x17d0 arch/x86/kernel/unwind_orc.c:444
 perf_callchain_kernel+0x38c/0x520 arch/x86/events/core.c:2343
 get_perf_callchain+0x2df/0x740 kernel/events/callchain.c:217
 perf_callchain+0x147/0x190 kernel/events/callchain.c:190
 perf_prepare_sample+0xd77/0x1380 kernel/events/core.c:6162
 __perf_event_output kernel/events/core.c:6278 [inline]
 perf_event_output_forward+0xc9/0x1f0 kernel/events/core.c:6296
 __perf_event_overflow+0x113/0x310 kernel/events/core.c:7541
 perf_swevent_hrtimer+0x220/0x350 kernel/events/core.c:8751
 __run_hrtimer kernel/time/hrtimer.c:1223 [inline]
 __hrtimer_run_queues+0x30b/0xc80 kernel/time/hrtimer.c:1287
 hrtimer_interrupt+0x1e6/0x5e0 kernel/time/hrtimer.c:1321
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x117/0x5e0 arch/x86/kernel/apic/apic.c:1100
 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:ffff8880a795fbb8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff0fa2d20 RBX: ffff8880a503e640 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8880a503eec4
RBP: ffff8880a503f7b0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 futex_cleanup_begin kernel/futex.c:3833 [inline]
 futex_exit_release+0x26/0x220 kernel/futex.c:3885
 retint_kernel+0x2d/0x2d
RIP: a503e640:acct_collect+0x1d8/0x7c0
RSP: 0000:0000000000000000 EFLAGS: ffff88809b4ad220 ORIG_RAX: ffff8880a47ba7d0
RAX: ffffffff87892fd0 RBX: ffff8880a503f7b0 RCX: ffffffff8653cf30
RDX: ffff8880a795fcc8 RSI: 1ffffffff0f3a5ad RDI: 1ffff11014f2bf9e
RBP: ffffffff8146f838 R08: 0000000041b58ab3 R09: 00000060fedbc8de
R10: ffffffff81003ce5 R11: ffffffff81529d96 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff11014f2bf8f R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea00029e57c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0xfffe0000000000()
raw: 00fffe0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a795fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a795fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1
>ffff8880a795fc80: f1 f1 f1 00 00 00 f2 00 00 00 f2 f2 f2 00 00 00
                                     ^
 ffff8880a795fd00: 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00
 ffff8880a795fd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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