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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 ffffc90002177550 by task syz-executor.2/20139

CPU: 0 PID: 20139 Comm: syz-executor.2 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:vm_normal_page+0x4a/0x380 mm/memory.c:593
Code: e5 48 c7 04 24 b3 8a b5 41 48 c7 44 24 08 e3 7b 69 89 48 c1 ed 03 48 c7 44 24 10 f0 6f a3 81 48 8d 44 1d 00 c7 00 f1 f1 f1 f1 <c7> 40 04 00 f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 44 24 58 31
RSP: 0018:ffffc90001c17938 EFLAGS: 00000a06
RAX: fffff52000382f27 RBX: dffffc0000000000 RCX: ffffffff81a38490
RDX: 800000005f19e007 RSI: 00007ffb1c896000 RDI: ffff88809e967988
RBP: 1ffff92000382f27 R08: 0000000000000000 R09: ffff88805ce68487
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809e967988
R13: 00007ffb1c896000 R14: dffffc0000000000 R15: 00007ffb1c897000
 zap_pte_range mm/memory.c:1062 [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+0xb91/0x2b20 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
 __do_sys_exit_group kernel/exit.c:915 [inline]
 __se_sys_exit_group kernel/exit.c:913 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:913
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:367
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007ffb1aeef488 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 000000000045cb29
RDX: 000000000045cb29 RSI: 00007ffb1aeef4c0 RDI: 000000000000000b
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000c31 R14: 00000000004ce7fd R15: 00007ffb1aef06d4


Memory state around the buggy address:
 ffffc90002177400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90002177480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90002177500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                 ^
 ffffc90002177580: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
 ffffc90002177600: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
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