==================================================================
BUG: KASAN: out-of-bounds in csd_lock_record+0xcb/0xe0 kernel/smp.c:118
Read of size 8 at addr ffffc90002457830 by task syz-executor.5/21608

CPU: 0 PID: 21608 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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x8c/0xe0 kernel/locking/spinlock.c:191
Code: 48 c7 c0 00 ff b4 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 37 48 83 3d 9b 74 c8 01 00 74 22 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 95 fb 62 f9 65 8b 05 fe 73 15 78
RSP: 0018:ffffc90018f97618 EFLAGS: 00000282
RAX: 1ffffffff1369fe0 RBX: 0000000000000282 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000282
RBP: ffff88809488d1c8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000282
R13: ffff88809488d1b0 R14: ffffc90018f97758 R15: ffff88809488d1c8
 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline]
 __skb_try_recv_datagram+0x162/0x3d0 net/core/datagram.c:267
 __skb_recv_datagram+0x1a1/0x220 net/core/datagram.c:297
 skb_recv_datagram+0xa7/0xe0 net/core/datagram.c:317
 netlink_recvmsg+0xe3/0xee0 net/netlink/af_netlink.c:1941
 sock_recvmsg_nosec net/socket.c:886 [inline]
 ____sys_recvmsg+0x561/0x640 net/socket.c:2573
 ___sys_recvmsg+0x127/0x200 net/socket.c:2617
 do_recvmmsg+0x24d/0x6d0 net/socket.c:2715
 __sys_recvmmsg net/socket.c:2796 [inline]
 __do_sys_recvmmsg net/socket.c:2817 [inline]
 __se_sys_recvmmsg net/socket.c:2810 [inline]
 __x64_sys_recvmmsg+0x17d/0x260 net/socket.c:2810
 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:00007f8480a40c78 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00000000004fc860 RCX: 000000000045cb29
RDX: 04000000000008e0 RSI: 0000000020002ec0 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 00000000200001c0 R09: 0000000000000000
R10: 000000000000000a R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008c7 R14: 00000000004cbb2f R15: 00007f8480a416d4


Memory state around the buggy address:
 ffffc90002457700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90002457780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90002457800: f1 f1 f1 f1 00 00 00 00 f3 f3 f3 f3 00 00 00 00
                                        ^
 ffffc90002457880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90002457900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================