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BUG: KASAN: stack-out-of-bounds in deref_stack_regs arch/x86/kernel/unwind_orc.c:308 [inline]
BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x1757/0x1810 arch/x86/kernel/unwind_orc.c:437
Read of size 8 at addr ffff8881d593fcf8 by task syz-executor.1/7849

CPU: 0 PID: 7849 Comm: syz-executor.1 Not tainted 4.14.157-syzkaller #0
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xe5/0x154 lib/dump_stack.c:58
 print_address_description+0x60/0x226 mm/kasan/report.c:187
 __kasan_report.cold+0x1a/0x41 mm/kasan/report.c:316
 deref_stack_regs arch/x86/kernel/unwind_orc.c:308 [inline]
 unwind_next_frame+0x1757/0x1810 arch/x86/kernel/unwind_orc.c:437
 perf_callchain_kernel+0x3a0/0x540 arch/x86/events/core.c:2338
 get_perf_callchain+0x2f5/0x770 kernel/events/callchain.c:217
 perf_callchain+0x147/0x190 kernel/events/callchain.c:190
 perf_prepare_sample+0x6a8/0x1360 kernel/events/core.c:6149
 __perf_event_output kernel/events/core.c:6265 [inline]
 perf_event_output_forward+0xdc/0x220 kernel/events/core.c:6283
 __perf_event_overflow+0x12d/0x340 kernel/events/core.c:7541
 perf_swevent_hrtimer+0x238/0x390 kernel/events/core.c:8746
 __run_hrtimer kernel/time/hrtimer.c:1259 [inline]
 __hrtimer_run_queues+0x28b/0xc40 kernel/time/hrtimer.c:1323
 hrtimer_interrupt+0x1bd/0x490 kernel/time/hrtimer.c:1357
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline]
 smp_apic_timer_interrupt+0x147/0x650 arch/x86/kernel/apic/apic.c:1100
 apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:792
 </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+0x69/0x360 kernel/locking/lockdep.c:3989
RSP: 0018:ffff8881d593fbd0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000007 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff8881b0465e00 RSI: 0000000000000000 RDI: ffff8881b046662c
RBP: ffff8881cfa3f0e0 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8881d593fdc0 R11: ffffffffaa030a2b R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 prepare_bprm_creds+0x51/0x110 fs/exec.c:1389
 prepare_bprm_creds+0x51/0x110 fs/exec.c:1389
 retint_kernel+0x2d/0x2d
RIP: 0000:0xffff8881b04665fc
RSP: a7d84c59:0000000000000000 EFLAGS: ffffffffa9200a3a ORIG_RAX: ffffc90002340000
RAX: ffffed103b7444fa RBX: 0000000000000000 RCX: ffff88821fffd01c
RDX: ffff8881d593fcf8 RSI: 1ffffffff5355888 RDI: 0000000000000000
RBP: ffffffffa79fdeab R08: ffffed103b7444f9 R09: ffffffffa909c0d0
R10: ffffffffa9a47d88 R11: 0000000041b58ab3 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: 1ffff1103ab27f92

The buggy address belongs to the page:
page:ffffea0007564fc0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 dead000000000200 ffff8881da802e00 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881d593fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881d593fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881d593fc80: 00 00 f1 f1 f1 f1 00 00 00 f2 00 00 00 f2 f2 f2
                                                                ^
 ffff8881d593fd00: 00 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00
 ffff8881d593fd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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