syzbot

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BUG: KCSAN: data-race in vti_rcv_cb / vti_rcv_cb

read to 0xffff88813cb05148 of 8 bytes by interrupt on cpu 0:
 vti_rcv_cb+0x7b/0x550 net/ipv4/ip_vti.c:110
 tunnel4_rcv_cb+0x9a/0x120 net/ipv4/tunnel4.c:124
 xfrm_rcv_cb net/xfrm/xfrm_input.c:111 [inline]
 xfrm_input+0x2b11/0x3340 net/xfrm/xfrm_input.c:751
 vti_input+0x2cf/0x2f0 net/ipv4/ip_vti.c:66
 vti_rcv_tunnel+0x72/0x80 net/ipv4/ip_vti.c:479
 tunnel4_rcv+0x6d/0x120 net/ipv4/tunnel4.c:103
 ip_protocol_deliver_rcu+0x291/0x540 net/ipv4/ip_input.c:204
 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip_local_deliver+0x1d6/0x2a0 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:460 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:429 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip_rcv+0x1a6/0x250 net/ipv4/ip_input.c:540
 __netif_receive_skb_one_core net/core/dev.c:5462 [inline]
 __netif_receive_skb+0x8b/0x1b0 net/core/dev.c:5576
 process_backlog+0x23f/0x3e0 net/core/dev.c:6452
 __napi_poll+0x65/0x3f0 net/core/dev.c:7020
 napi_poll net/core/dev.c:7087 [inline]
 net_rx_action+0x29e/0x650 net/core/dev.c:7174
 __do_softirq+0x158/0x2de kernel/softirq.c:558
 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:920
 smpboot_thread_fn+0x308/0x4a0 kernel/smpboot.c:164
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

write to 0xffff88813cb05148 of 8 bytes by interrupt on cpu 1:
 vti_rcv_cb+0x8d/0x550 net/ipv4/ip_vti.c:110
 tunnel4_rcv_cb+0x9a/0x120 net/ipv4/tunnel4.c:124
 xfrm_rcv_cb net/xfrm/xfrm_input.c:111 [inline]
 xfrm_input+0x2b11/0x3340 net/xfrm/xfrm_input.c:751
 vti_input+0x2cf/0x2f0 net/ipv4/ip_vti.c:66
 vti_rcv_tunnel+0x72/0x80 net/ipv4/ip_vti.c:479
 tunnel4_rcv+0x6d/0x120 net/ipv4/tunnel4.c:103
 ip_protocol_deliver_rcu+0x291/0x540 net/ipv4/ip_input.c:204
 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip_local_deliver+0x1d6/0x2a0 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:460 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:429 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip_rcv+0x1a6/0x250 net/ipv4/ip_input.c:540
 __netif_receive_skb_one_core net/core/dev.c:5462 [inline]
 __netif_receive_skb+0x8b/0x1b0 net/core/dev.c:5576
 process_backlog+0x23f/0x3e0 net/core/dev.c:6452
 __napi_poll+0x65/0x3f0 net/core/dev.c:7020
 napi_poll net/core/dev.c:7087 [inline]
 net_rx_action+0x29e/0x650 net/core/dev.c:7174
 __do_softirq+0x158/0x2de kernel/softirq.c:558
 do_softirq+0xb1/0xf0 kernel/softirq.c:459
 __local_bh_enable_ip+0x68/0x70 kernel/softirq.c:383
 local_bh_enable+0x1b/0x20 include/linux/bottom_half.h:33
 rcu_read_unlock_bh include/linux/rcupdate.h:758 [inline]
 ip_finish_output2+0x735/0xb40 net/ipv4/ip_output.c:222
 ip_finish_output+0xfb/0x240 net/ipv4/ip_output.c:309
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:423
 dst_output include/net/dst.h:450 [inline]
 ip_local_out net/ipv4/ip_output.c:126 [inline]
 ip_send_skb+0x6e/0xe0 net/ipv4/ip_output.c:1555
 udp_send_skb+0x62d/0x860 net/ipv4/udp.c:966
 udp_sendmsg+0x12e4/0x14c0 net/ipv4/udp.c:1253
 udpv6_sendmsg+0x6a3/0x16e0
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:644
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2409
 ___sys_sendmsg net/socket.c:2463 [inline]
 __sys_sendmmsg+0x267/0x4c0 net/socket.c:2549
 __do_sys_sendmmsg net/socket.c:2578 [inline]
 __se_sys_sendmmsg net/socket.c:2575 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000018f75 -> 0x0000000000018f76

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13606 Comm: syz-executor.0 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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