==================================================================
BUG: KASAN: out-of-bounds in csd_lock_record+0xcb/0xe0 kernel/smp.c:118
Read of size 8 at addr ffffc900052f7830 by task syz-executor.3/15368

CPU: 1 PID: 15368 Comm: syz-executor.3 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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199
Code: c0 10 ff b4 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d ee 7a c8 01 00 74 25 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 db 01 63 f9 65 8b 05 44 7a 15 78 85 c0 74 02 5d
RSP: 0018:ffffc9001947f568 EFLAGS: 00000286
RAX: 1ffffffff1369fe2 RBX: ffff888091a0a5c0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff87ec83ff
RBP: ffff8880ae735e00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880ae735e00
R13: ffff888056cc0300 R14: 0000000000000000 R15: 0000000000000001
 finish_lock_switch kernel/sched/core.c:3184 [inline]
 finish_task_switch+0x147/0x750 kernel/sched/core.c:3284
 context_switch kernel/sched/core.c:3448 [inline]
 __schedule+0x8bc/0x1e80 kernel/sched/core.c:4169
 preempt_schedule_irq+0xb0/0x150 kernel/sched/core.c:4427
 idtentry_exit_cond_resched arch/x86/entry/common.c:645 [inline]
 idtentry_exit_cond_rcu+0xc0/0xf0 arch/x86/entry/common.c:692
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596
RIP: 0010:pud_pfn_mask arch/x86/include/asm/pgtable_types.h:427 [inline]
RIP: 0010:pud_flags_mask arch/x86/include/asm/pgtable_types.h:435 [inline]
RIP: 0010:pud_flags arch/x86/include/asm/pgtable_types.h:440 [inline]
RIP: 0010:pud_bad arch/x86/include/asm/pgtable.h:889 [inline]
RIP: 0010:pud_none_or_clear_bad include/linux/pgtable.h:763 [inline]
RIP: 0010:zap_pud_range mm/memory.c:1220 [inline]
RIP: 0010:zap_p4d_range mm/memory.c:1243 [inline]
RIP: 0010:unmap_page_range+0x55f/0x2b20 mm/memory.c:1264
Code: 3c 30 00 0f 85 f4 20 00 00 48 8b 04 24 31 ff 48 8b 28 48 89 eb 48 83 e3 9f 48 89 de e8 2a 85 d0 ff 48 85 db 0f 84 f6 0b 00 00 <e8> 7c 88 d0 ff 49 89 ec 31 ff 48 bb ff ff ff 3f 00 00 f0 ff 41 81
RSP: 0018:ffffc9001947f790 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000094986007 RCX: ffffffff81a37e76
RDX: 0000000094986007 RSI: ffff888091a0a5c0 RDI: 0000000000000007
RBP: 0000000094986067 R08: 0000000000000000 R09: ffff888033555d83
R10: 0000000000000000 R11: 0000000000000000 R12: 00007fffffffffff
R13: 00007fed9b379000 R14: dffffc0000000000 R15: 00007fed9b579000
 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:00007fed99d77cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000078bf08 RCX: 000000000045cb29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078bf08
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fff66f9c59f R14: 00007fed99d789c0 R15: 000000000078bf0c


Memory state around the buggy address:
 ffffc900052f7700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900052f7780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900052f7800: f1 f1 f1 f1 00 00 00 00 f3 f3 f3 f3 00 00 00 00
                                        ^
 ffffc900052f7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900052f7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================