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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 ffffc90005157550 by task syz-executor.0/29912

CPU: 0 PID: 29912 Comm: syz-executor.0 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:check_memory_region+0x134/0x180 mm/kasan/generic.c:193
Code: 85 d2 75 0b 48 89 da 48 29 c2 e9 55 ff ff ff 49 39 d2 75 17 49 0f be 02 41 83 e1 07 49 39 c1 7d 0a 5b b8 01 00 00 00 5d 41 5c <c3> 44 89 c2 e8 43 f0 ff ff 5b 83 f0 01 5d 41 5c c3 48 29 c3 48 89
RSP: 0018:ffffc900052d7748 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81a86dae
RDX: fffff940004d8fc7 RSI: 0000000000000004 RDI: ffffea00026c7e30
RBP: ffffea00026c7e00 R08: 0000000000000001 R09: ffffea00026c7e33
R10: fffff940004d8fc6 R11: 0000000000000000 R12: 0000000000000000
R13: ffffea00026c7e08 R14: 0000000000000000 R15: dead000000000100
 instrument_atomic_write include/linux/instrumented.h:71 [inline]
 atomic_add_negative include/asm-generic/atomic-instrumented.h:768 [inline]
 page_remove_file_rmap mm/rmap.c:1260 [inline]
 page_remove_rmap+0x9de/0x1670 mm/rmap.c:1331
 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:00007fe64a99ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000078c0e8 RCX: 000000000045cb29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078c0e8
RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c0ec
R13: 00007ffc3e321cef R14: 00007fe64a99d9c0 R15: 000000000078c0ec


Memory state around the buggy address:
 ffffc90005157400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90005157480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90005157500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                 ^
 ffffc90005157580: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
 ffffc90005157600: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
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