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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 ffffc900052d7830 by task syz-executor.3/31086

CPU: 0 PID: 31086 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:__rcu_read_lock+0x5a/0x90 kernel/rcu/tree_plugin.h:376
Code: 78 03 00 00 01 48 b8 00 00 00 00 00 fc ff df 65 48 8b 1c 25 c0 fe 01 00 48 8d bb 78 03 00 00 48 89 fa 48 c1 ea 03 0f b6 04 02 <84> c0 74 04 3c 03 7e 19 81 bb 78 03 00 00 ff ff ff 3f 7f 02 5b c3
RSP: 0018:ffffc900178f7658 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: ffff88804942e500 RCX: ffffc9000eb95000
RDX: 1ffff11009285d0f RSI: ffffffff81a863ed RDI: ffff88804942e878
RBP: ffffea0001634600 R08: 0000000000000000 R09: ffffea0001634607
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffea0001634608 R14: dffffc0000000000 R15: 00007f056ee11000
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 lock_page_memcg+0x43/0x260 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
 copy_process+0x4f5c/0x6b90 kernel/fork.c:2319
 _do_fork+0x12c/0xa70 kernel/fork.c:2425
 __do_sys_clone3+0x1dd/0x320 kernel/fork.c:2748
 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:00007f056eae2c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00000000004db5e0 RCX: 000000000045cb29
RDX: 0000000000000000 RSI: 0000000000000058 RDI: 00000000200003c0
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000007d R14: 00000000004c34c0 R15: 00007f056eae36d4


Memory state around the buggy address:
 ffffc900052d7700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900052d7780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900052d7800: f1 f1 f1 f1 00 00 00 00 f3 f3 f3 f3 00 00 00 00
                                        ^
 ffffc900052d7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900052d7900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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