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BUG: KASAN: stack-out-of-bounds in deref_stack_regs arch/x86/kernel/unwind_orc.c:304 [inline]
BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x146f/0x17d0 arch/x86/kernel/unwind_orc.c:437
Read of size 8 at addr ffff8880970879a8 by task syz-executor260/8008

CPU: 0 PID: 8008 Comm: syz-executor260 Not tainted 4.14.212-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __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:304 [inline]
 unwind_next_frame+0x146f/0x17d0 arch/x86/kernel/unwind_orc.c:437
 perf_callchain_kernel+0x38c/0x520 arch/x86/events/core.c:2343
 get_perf_callchain+0x2de/0x740 kernel/events/callchain.c:217
 perf_callchain+0x147/0x190 kernel/events/callchain.c:190
 perf_prepare_sample+0xd77/0x1380 kernel/events/core.c:6164
 __perf_event_output kernel/events/core.c:6280 [inline]
 perf_event_output_forward+0xc9/0x1f0 kernel/events/core.c:6298
 __perf_event_overflow+0x113/0x310 kernel/events/core.c:7547
 perf_swevent_overflow kernel/events/core.c:7623 [inline]
 perf_swevent_event+0x299/0x460 kernel/events/core.c:7651
 perf_tp_event+0x540/0x6e0 kernel/events/core.c:8085
 perf_trace_run_bpf_submit+0x119/0x200 kernel/events/core.c:8055
 perf_trace_lock+0x2d6/0x490 include/trace/events/lock.h:39
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0x4df/0x870 kernel/locking/lockdep.c:4016
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_unlock_irqrestore+0x1b/0xe0 kernel/locking/spinlock.c:192
 __debug_check_no_obj_freed lib/debugobjects.c:760 [inline]
 debug_check_no_obj_freed+0x2c0/0x674 lib/debugobjects.c:776
 kmem_cache_free+0x156/0x2b0 mm/slab.c:3757
 pgtable_pmd_page_dtor include/linux/mm.h:1864 [inline]
 ___pmd_free_tlb+0xa3/0xf0 arch/x86/mm/pgtable.c:76
 __pmd_free_tlb arch/x86/include/asm/pgalloc.h:124 [inline]
 free_pmd_range mm/memory.c:495 [inline]
 free_pud_range mm/memory.c:513 [inline]
 free_p4d_range mm/memory.c:546 [inline]
 free_pgd_range+0x697/0xcd0 mm/memory.c:626
 free_pgtables+0x1ec/0x2b0 mm/memory.c:658
 exit_mmap+0x27f/0x4d0 mm/mmap.c:3059
 __mmput kernel/fork.c:930 [inline]
 mmput kernel/fork.c:951 [inline]
 mmput+0xfa/0x420 kernel/fork.c:946
 exit_mm kernel/exit.c:548 [inline]
 do_exit+0x984/0x2850 kernel/exit.c:855
 do_group_exit+0x100/0x2e0 kernel/exit.c:965
 SYSC_exit_group kernel/exit.c:976 [inline]
 SyS_exit_group+0x19/0x20 kernel/exit.c:974
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x43ff58
RSP: 002b:00007ffd658f4788 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff58
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004bf7f0 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea00025c21c0 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:
 ffff888097087880: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 f1 f1 04
 ffff888097087900: f2 00 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 f1
>ffff888097087980: f1 f1 f1 04 f3 f3 f3 00 00 00 00 00 00 00 00 00
                                  ^
 ffff888097087a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1
 ffff888097087a80: f1 f1 00 f3 f3 f3 00 00 00 00 00 00 00 00 00 00
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