syzbot

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BUG: KCSAN: data-race in ip_tunnel_rcv / ip_tunnel_rcv

read to 0xffff88813463c170 of 8 bytes by interrupt on cpu 0:
 ip_tunnel_rcv+0xc0/0x1370 net/ipv4/ip_tunnel.c:371
 erspan_rcv net/ipv4/ip_gre.c:341 [inline]
 gre_rcv+0x848/0x8d0 net/ipv4/ip_gre.c:442
 gre_rcv+0xb8/0x130 net/ipv4/gre_demux.c:163
 ip_protocol_deliver_rcu+0x2a8/0x570 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:461 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:429 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip_rcv+0x1b1/0x260 net/ipv4/ip_input.c:540
 __netif_receive_skb_one_core net/core/dev.c:5351 [inline]
 __netif_receive_skb+0x8b/0x1b0 net/core/dev.c:5465
 process_backlog+0x23f/0x3e0 net/core/dev.c:5797
 __napi_poll+0x65/0x3f0 net/core/dev.c:6365
 napi_poll net/core/dev.c:6432 [inline]
 net_rx_action+0x29e/0x650 net/core/dev.c:6519
 __do_softirq+0x158/0x2de kernel/softirq.c:558
 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:921
 smpboot_thread_fn+0x308/0x4a0 kernel/smpboot.c:164
 kthread+0x1bf/0x1e0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30

write to 0xffff88813463c170 of 8 bytes by interrupt on cpu 1:
 ip_tunnel_rcv+0xd2/0x1370 net/ipv4/ip_tunnel.c:371
 erspan_rcv net/ipv4/ip_gre.c:341 [inline]
 gre_rcv+0x848/0x8d0 net/ipv4/ip_gre.c:442
 gre_rcv+0xb8/0x130 net/ipv4/gre_demux.c:163
 ip_protocol_deliver_rcu+0x2a8/0x570 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:461 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:429 [inline]
 NF_HOOK include/linux/netfilter.h:307 [inline]
 ip_rcv+0x1b1/0x260 net/ipv4/ip_input.c:540
 __netif_receive_skb_one_core net/core/dev.c:5351 [inline]
 __netif_receive_skb+0x8b/0x1b0 net/core/dev.c:5465
 process_backlog+0x23f/0x3e0 net/core/dev.c:5797
 __napi_poll+0x65/0x3f0 net/core/dev.c:6365
 napi_poll net/core/dev.c:6432 [inline]
 net_rx_action+0x29e/0x650 net/core/dev.c:6519
 __do_softirq+0x158/0x2de kernel/softirq.c:558
 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:921
 smpboot_thread_fn+0x308/0x4a0 kernel/smpboot.c:164
 kthread+0x1bf/0x1e0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30

value changed: 0x00000000000081bd -> 0x00000000000081be

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 5.17.0-rc3-syzkaller-00247-g83e396641110-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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