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BUG: KASAN: stack-out-of-bounds in csd_lock_record+0xcb/0xe0 kernel/smp.c:118
Read of size 8 at addr ffffc90000dd7970 by task syz-executor.2/26572

CPU: 1 PID: 26572 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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline]
RIP: 0010:lock_acquire+0x270/0xad0 kernel/locking/lockdep.c:4962
Code: 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 f8 06 00 00 48 83 3d 6d c1 5a 08 00 0f 84 a6 05 00 00 48 8b 7c 24 08 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 10 48 c7
RSP: 0018:ffffc90008f77850 EFLAGS: 00000282
RAX: 1ffffffff1369fe0 RBX: ffff88804be38480 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: c679db7d3420969b RDI: 0000000000000282
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8c5a7a27
R10: fffffbfff18b4f44 R11: 0000000000000000 R12: 0000000000000002
R13: ffffffff89bc3040 R14: 0000000000000000 R15: ffff8880a86eaa28
 rcu_lock_acquire include/linux/rcupdate.h:241 [inline]
 rcu_read_lock include/linux/rcupdate.h:634 [inline]
 lock_page_memcg+0x63/0x260 mm/memcontrol.c:2084
 page_remove_rmap+0x25/0x1670 mm/rmap.c:1328
 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
 __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:00007fadd66f81c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000000b RCX: 000000000045cb29
RDX: 00000000004572d0 RSI: 00007fadd66f8200 RDI: 000000000000000b
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000f R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000c56 R14: 00000000004ceae2 R15: 00007fadd66f96d4


Memory state around the buggy address:
 ffffc90000dd7800: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
 ffffc90000dd7880: 00 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3
>ffffc90000dd7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1
                                                             ^
 ffffc90000dd7980: f1 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00
 ffffc90000dd7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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