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BUG: KASAN: out-of-bounds in csd_lock_record+0xcb/0xe0 kernel/smp.c:118
Read of size 8 at addr ffffc900019e7530 by task syz-executor.5/8931

CPU: 1 PID: 8931 Comm: syz-executor.5 Not tainted 5.8.0-rc3-next-20200703-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:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 csd_lock_record+0xcb/0xe0 kernel/smp.c:118
 flush_smp_call_function_queue+0x285/0x730 kernel/smp.c:391
 __sysvec_call_function_single+0x98/0x490 arch/x86/kernel/smp.c:248
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_call_function_single+0xe0/0x120 arch/x86/kernel/smp.c:243
 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:604
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline]
RIP: 0010:lock_release+0x481/0x8d0 kernel/locking/lockdep.c:4980
Code: 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 7f 03 00 00 48 83 3d 2b c8 5a 08 00 0f 84 a9 01 00 00 48 8b 3c 24 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c5 48 c7 45 00
RSP: 0018:ffffc90001d376c8 EFLAGS: 00000282
RAX: 1ffffffff1369fe0 RBX: ffff88809e358040 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff89bc3040 RDI: 0000000000000282
RBP: 1ffff920003a6edb R08: 0000000000000001 R09: ffff88809e358910
R10: fffffbfff155e051 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff81b8ffff R14: 0000000000000002 R15: ffff88809e358040
 zap_pte_range mm/memory.c:1089 [inline]
 zap_pmd_range mm/memory.c:1193 [inline]
 zap_pud_range mm/memory.c:1222 [inline]
 zap_p4d_range mm/memory.c:1243 [inline]
 unmap_page_range+0xf3c/0x2b20 mm/memory.c:1264
 unmap_single_vma+0x198/0x300 mm/memory.c:1309
 unmap_vmas+0x16f/0x2f0 mm/memory.c:1341
 exit_mmap+0x2b1/0x530 mm/mmap.c:3165
 __mmput+0x122/0x470 kernel/fork.c:1075
 mmput+0x53/0x60 kernel/fork.c:1096
 exit_mm kernel/exit.c:483 [inline]
 do_exit+0xa8f/0x2a40 kernel/exit.c:793
 do_group_exit+0x125/0x310 kernel/exit.c:904
 get_signal+0x40b/0x1ee0 kernel/signal.c:2743
 do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810
 exit_to_usermode_loop arch/x86/entry/common.c:218 [inline]
 __prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:252
 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:376
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007fd7835e3c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: fffffffffffffff4 RBX: 00000000004f7320 RCX: 000000000045cb29
RDX: 0000000020000040 RSI: 00000000200000c0 RDI: 0000000020000480
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000772 R14: 00000000004ca761 R15: 00007fd7835e46d4


Memory state around the buggy address:
 ffffc900019e7400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900019e7480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900019e7500: f1 f1 f1 f1 00 00 00 00 f3 f3 f3 f3 00 00 00 00
                                     ^
 ffffc900019e7580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900019e7600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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