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BUG: KMSAN: uninit-value in tcp_parse_options+0x1161/0x1c70 net/ipv4/tcp_input.c:3720
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.16.0+ #86
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x185/0x1d0 lib/dump_stack.c:53
 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:683
 tcp_parse_options+0x1161/0x1c70 net/ipv4/tcp_input.c:3720
 tcp_fast_parse_options net/ipv4/tcp_input.c:3858 [inline]
 tcp_validate_incoming+0x4f1/0x2790 net/ipv4/tcp_input.c:5184
 tcp_rcv_established+0xf60/0x2bb0 net/ipv4/tcp_input.c:5453
 tcp_v4_do_rcv+0x6cd/0xd90 net/ipv4/tcp_ipv4.c:1469
 tcp_v4_rcv+0x5ecf/0x6af0 net/ipv4/tcp_ipv4.c:1746
 ip_local_deliver_finish+0x874/0xec0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:449 [inline]
 ip_rcv_finish+0xa36/0x1d00 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x118f/0x16d0 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x47df/0x4a90 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:365 [inline]
 irq_exit+0x202/0x240 kernel/softirq.c:405
 exiting_irq+0xe/0x10 arch/x86/include/asm/apic.h:541
 smp_apic_timer_interrupt+0x64/0x90 arch/x86/kernel/apic/apic.c:1055
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857
 </IRQ>
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:55 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:97 [inline]
RIP: 0010:default_idle+0x1fb/0x3c0 arch/x86/kernel/process.c:354
RSP: 0018:ffffffff8aa0fd88 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff12
RAX: ffff8801fddd81a0 RBX: 0000000000000000 RCX: ffff880000000000
RDX: ffff8801fd9d81a0 RSI: aaaaaaaaaaaab000 RDI: ffffea0000000000
RBP: ffffffff8aa0fdc0 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8aa36c00 R14: ffffffff8aa0fe24 R15: ffffffff8aa37518
 arch_cpu_idle+0x20/0x30 arch/x86/kernel/process.c:345
 default_idle_call kernel/sched/idle.c:98 [inline]
 cpuidle_idle_call kernel/sched/idle.c:156 [inline]
 do_idle+0x349/0x790 kernel/sched/idle.c:246
 cpu_startup_entry+0x45/0x50 kernel/sched/idle.c:351
 rest_init+0x1c1/0x1f0 init/main.c:438
 start_kernel+0xf93/0xfb0 init/main.c:719
 x86_64_start_reservations arch/x86/kernel/head64.c:378 [inline]
 x86_64_start_kernel+0x2fa/0x310 arch/x86/kernel/head64.c:359
 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321
 slab_post_alloc_hook mm/slab.h:445 [inline]
 slab_alloc_node mm/slub.c:2737 [inline]
 __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:984 [inline]
 tcp_send_ack+0x18c/0x910 net/ipv4/tcp_output.c:3624
 __tcp_ack_snd_check net/ipv4/tcp_input.c:5040 [inline]
 tcp_ack_snd_check net/ipv4/tcp_input.c:5053 [inline]
 tcp_rcv_established+0x2103/0x2bb0 net/ipv4/tcp_input.c:5469
 tcp_v4_do_rcv+0x6cd/0xd90 net/ipv4/tcp_ipv4.c:1469
 tcp_v4_rcv+0x5ecf/0x6af0 net/ipv4/tcp_ipv4.c:1746
 ip_local_deliver_finish+0x874/0xec0 net/ipv4/ip_input.c:216
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_local_deliver+0x43c/0x4e0 net/ipv4/ip_input.c:257
 dst_input include/net/dst.h:449 [inline]
 ip_rcv_finish+0xa36/0x1d00 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x118f/0x16d0 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x47df/0x4a90 net/core/dev.c:4562
 __netif_receive_skb net/core/dev.c:4627 [inline]
 process_backlog+0x62d/0xe20 net/core/dev.c:5307
 napi_poll net/core/dev.c:5705 [inline]
 net_rx_action+0x7c1/0x1a70 net/core/dev.c:5771
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
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