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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 ffffc90017697930 by task syz-executor.5/7271

CPU: 1 PID: 7271 Comm: syz-executor.5 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:__kasan_check_read+0x0/0x10 mm/kasan/common.c:71
Code: fb 01 8b 5c 24 04 e9 75 b8 ff ff 48 8b 73 58 89 c2 48 c7 c7 80 aa 69 89 f7 da e8 5a f2 a9 ff e9 9d f5 ff ff cc cc cc cc cc cc <48> 8b 0c 24 89 f6 31 d2 e9 43 2a 00 00 0f 1f 00 48 8b 0c 24 89 f6
RSP: 0018:ffffc90007b2f870 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffea00014daac0 RCX: ffffffff81a4b2f9
RDX: ffff888050d66300 RSI: 0000000000000004 RDI: ffffea00014daaf4
RBP: ffffea00014daaf4 R08: 0000000000000000 R09: ffffea00014daa87
R10: 0000000000000000 R11: 0000000000000000 R12: 80000000536ab007
R13: dffffc0000000000 R14: ffffea00014daac0 R15: 0000000000000010
 instrument_atomic_read include/linux/instrumented.h:56 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
 page_ref_count include/linux/page_ref.h:67 [inline]
 get_page include/linux/mm.h:1139 [inline]
 copy_one_pte mm/memory.c:801 [inline]
 copy_pte_range mm/memory.c:850 [inline]
 copy_pmd_range mm/memory.c:901 [inline]
 copy_pud_range mm/memory.c:935 [inline]
 copy_p4d_range mm/memory.c:957 [inline]
 copy_page_range+0xf88/0x2750 mm/memory.c:1019
 dup_mmap kernel/fork.c:591 [inline]
 dup_mm+0x98f/0x1300 kernel/fork.c:1353
 copy_mm kernel/fork.c:1409 [inline]
 copy_process+0x28ba/0x6b90 kernel/fork.c:2080
 _do_fork+0x12c/0xa70 kernel/fork.c:2425
 __do_sys_clone+0xef/0x150 kernel/fork.c:2581
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:367
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45b15a
Code: Bad RIP value.
RSP: 002b:00007ffe3ee10950 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffe3ee10950 RCX: 000000000045b15a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffe3ee10990 R08: 0000000000000001 R09: 0000000001d8e940
R10: 0000000001d8ec10 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffe3ee109e0


Memory state around the buggy address:
 ffffc90017697800: 00 00 f1 f1 f1 f1 00 00 00 00 00 00 00 00 00 00
 ffffc90017697880: 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00
>ffffc90017697900: 00 00 00 f1 f1 f1 f1 00 00 00 f3 f3 f3 f3 f3 00
                                     ^
 ffffc90017697980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90017697a00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
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