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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 ffffc90004fe7550 by task syz-executor.4/29561

CPU: 0 PID: 29561 Comm: syz-executor.4 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:nf_nat_inet_fn+0x64d/0xb70 net/netfilter/nf_nat_core.c:760
Code: 09 e8 f8 fa 48 8b 44 24 20 83 c3 01 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 74 08 3c 01 0f 8e 4c 04 00 00 41 0f b7 2e <89> de 49 83 c5 10 89 ef e8 d6 e3 f8 fa 39 dd 0f 8e ed 00 00 00 e8
RSP: 0018:ffffc90004f37268 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: 0000000000040000 RSI: ffffffff867b1ef7 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88809e988388 R14: ffff88809e988380 R15: 0000000000000100
 nf_nat_ipv4_fn net/netfilter/nf_nat_proto.c:645 [inline]
 nf_nat_ipv4_out+0xa0/0x4f0 net/netfilter/nf_nat_proto.c:673
 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
 nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:512
 nf_hook+0x2b8/0x540 include/linux/netfilter.h:262
 NF_HOOK_COND include/linux/netfilter.h:295 [inline]
 ip_output+0x216/0x310 net/ipv4/ip_output.c:430
 dst_output include/net/dst.h:435 [inline]
 ip_local_out net/ipv4/ip_output.c:125 [inline]
 __ip_queue_xmit+0x8e9/0x19c0 net/ipv4/ip_output.c:530
 sctp_packet_transmit+0x20d7/0x3240 net/sctp/output.c:629
 sctp_outq_flush_transports net/sctp/outqueue.c:1147 [inline]
 sctp_outq_flush+0x2b7/0x2380 net/sctp/outqueue.c:1195
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1801 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline]
 sctp_do_sm+0x4d0/0x4d80 net/sctp/sm_sideeffect.c:1156
 sctp_primitive_REQUESTHEARTBEAT+0x9b/0xc0 net/sctp/primitive.c:185
 sctp_apply_peer_addr_params+0x110/0x1ed0 net/sctp/socket.c:2452
 sctp_setsockopt_peer_addr_params+0x457/0x510 net/sctp/socket.c:2706
 sctp_setsockopt net/sctp/socket.c:4738 [inline]
 sctp_setsockopt+0x255b/0x70d0 net/sctp/socket.c:4677
 __sys_setsockopt+0x24a/0x480 net/socket.c:2127
 __do_sys_setsockopt net/socket.c:2143 [inline]
 __se_sys_setsockopt net/socket.c:2140 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2140
 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:00007f9df4ef7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000505de0 RCX: 000000000045cb29
RDX: 0000000000000009 RSI: 0000000000000084 RDI: 0000000000000003
RBP: 000000000078bfa0 R08: 000000000000009c R09: 0000000000000000
R10: 0000000020000300 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000b1d R14: 00000000004d7ba8 R15: 00007f9df4ef86d4


Memory state around the buggy address:
 ffffc90004fe7400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90004fe7480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90004fe7500: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 f3 f3 f3 f3
                                                    ^
 ffffc90004fe7580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90004fe7600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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