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BUG: KMSAN: uninit-value in tcp_parse_options+0xd74/0x1a30 net/ipv4/tcp_input.c:3720
CPU: 1 PID: 5034 Comm: udevd Not tainted 4.16.0+ #83
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:676
 tcp_parse_options+0xd74/0x1a30 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_state_process+0xb19/0x6490 net/ipv4/tcp_input.c:5875
 tcp_v4_do_rcv+0xb26/0xd90 net/ipv4/tcp_ipv4.c:1491
 tcp_v4_rcv+0x5b25/0x6750 net/ipv4/tcp_ipv4.c:1746
 ip_local_deliver_finish+0x6ed/0xd40 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+0x1253/0x16d0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x47cf/0x4a80 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:set_nlink+0x1/0x280 fs/inode.c:317
RSP: 0018:ffff8801696af7b8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff12
RAX: 0000000000000000 RBX: 000000000000000c RCX: 0000000000000000
RDX: 0000000081e00009 RSI: 000000000000000c RDI: ffff8801dd9f2e10
RBP: ffff8801696af870 R08: 0000000001080020 R09: 0000000000000002
R10: 0000000000000000 R11: ffff8801696a0000 R12: ffff8801dfbb9040
R13: 0000000000000000 R14: 0000000000000001 R15: ffff88016a270918
 kernfs_iop_permission+0xc7/0x160 fs/kernfs/inode.c:302
 do_inode_permission fs/namei.c:383 [inline]
 inode_permission+0x1ec/0x8c0 fs/namei.c:448
 may_lookup fs/namei.c:1655 [inline]
 link_path_walk+0x218/0x2140 fs/namei.c:2035
 path_lookupat+0x1cb/0x1140 fs/namei.c:2280
 filename_lookup+0x2bb/0xa60 fs/namei.c:2315
 user_path_at_empty+0x123/0x140 fs/namei.c:2569
 SYSC_readlinkat+0x163/0x4e0 fs/stat.c:394
 SyS_readlinkat+0x64/0x90 fs/stat.c:382
 SYSC_readlink+0x98/0xb0 fs/stat.c:421
 SyS_readlink+0x55/0x80 fs/stat.c:418
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x7fb162a48577
RSP: 002b:00007fffe776a6e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 0000000001c59250 RCX: 00007fb162a48577
RDX: 0000000000000400 RSI: 00007fffe776a6f0 RDI: 00007fffe776abd0
RBP: 0000000001c72090 R08: 0000000001c72090 R09: 7665642f7379732f
R10: 7269762f73656369 R11: 0000000000000246 R12: 00007fffe776abd0
R13: 0000000000000400 R14: 0000000001c59250 R15: 000000000000000b

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_fin+0x298/0x8f0 net/ipv4/tcp_input.c:4048
 tcp_ofo_queue net/ipv4/tcp_input.c:4349 [inline]
 tcp_data_queue+0x2cb9/0xa200 net/ipv4/tcp_input.c:4622
 tcp_rcv_state_process+0x5c61/0x6490 net/ipv4/tcp_input.c:6044
 tcp_v4_do_rcv+0xb26/0xd90 net/ipv4/tcp_ipv4.c:1491
 tcp_v4_rcv+0x5b25/0x6750 net/ipv4/tcp_ipv4.c:1746
 ip_local_deliver_finish+0x6ed/0xd40 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+0x1253/0x16d0 net/ipv4/ip_input.c:397
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x119d/0x16f0 net/ipv4/ip_input.c:493
 __netif_receive_skb_core+0x47cf/0x4a80 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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