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BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit

write to 0xffff88812ed5c170 of 8 bytes by interrupt on cpu 1:
 ip_tunnel_xmit+0x907/0x11a0 net/ipv4/ip_tunnel.c:762
 sit_tunnel_xmit__ net/ipv6/sit.c:1065 [inline]
 sit_tunnel_xmit+0x3c2/0x11f0 net/ipv6/sit.c:1081
 __netdev_start_xmit include/linux/netdevice.h:4944 [inline]
 netdev_start_xmit include/linux/netdevice.h:4958 [inline]
 xmit_one+0xf9/0x270 net/core/dev.c:3659
 dev_hard_start_xmit net/core/dev.c:3675 [inline]
 __dev_queue_xmit+0x693/0xa50 net/core/dev.c:4285
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4318
 neigh_connected_output+0x264/0x290 net/core/neighbour.c:1525
 neigh_output include/net/neighbour.h:510 [inline]
 ip_finish_output2+0x874/0xb10 net/ipv4/ip_output.c:230
 __ip_finish_output net/ipv4/ip_output.c:252 [inline]
 ip_finish_output+0x2fa/0x490 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:448 [inline]
 ip_local_out+0x164/0x220 net/ipv4/ip_output.c:126
 __ip_queue_xmit+0x97f/0x9a0 net/ipv4/ip_output.c:533
 ip_queue_xmit+0x34/0x40 net/ipv4/ip_output.c:547
 __tcp_transmit_skb+0x140a/0x19d0 net/ipv4/tcp_output.c:1405
 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline]
 tcp_xmit_probe_skb net/ipv4/tcp_output.c:4010 [inline]
 tcp_write_wakeup+0x28f/0x810 net/ipv4/tcp_output.c:4062
 tcp_send_probe0+0x2c/0x2b0 net/ipv4/tcp_output.c:4078
 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline]
 tcp_write_timer_handler+0x394/0x520 net/ipv4/tcp_timer.c:626
 tcp_write_timer+0xb9/0x180 net/ipv4/tcp_timer.c:642
 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1419
 expire_timers+0x135/0x250 kernel/time/timer.c:1464
 __run_timers+0x358/0x420 kernel/time/timer.c:1732
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1745
 __do_softirq+0x12c/0x26e kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x9a/0xb0 kernel/softirq.c:636
 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
 acpi_idle_do_entry drivers/acpi/processor_idle.c:553 [inline]
 acpi_idle_enter+0x258/0x2e0 drivers/acpi/processor_idle.c:688
 cpuidle_enter_state+0x2b6/0x750 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x1a3/0x240 kernel/sched/idle.c:306
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403
 secondary_startup_64_no_verify+0xb0/0xbb

read to 0xffff88812ed5c170 of 8 bytes by interrupt on cpu 0:
 ip_tunnel_xmit+0x8f5/0x11a0 net/ipv4/ip_tunnel.c:762
 sit_tunnel_xmit__ net/ipv6/sit.c:1065 [inline]
 sit_tunnel_xmit+0x3c2/0x11f0 net/ipv6/sit.c:1081
 __netdev_start_xmit include/linux/netdevice.h:4944 [inline]
 netdev_start_xmit include/linux/netdevice.h:4958 [inline]
 xmit_one+0xf9/0x270 net/core/dev.c:3659
 dev_hard_start_xmit net/core/dev.c:3675 [inline]
 __dev_queue_xmit+0x693/0xa50 net/core/dev.c:4285
 dev_queue_xmit+0x13/0x20 net/core/dev.c:4318
 neigh_connected_output+0x264/0x290 net/core/neighbour.c:1525
 neigh_output include/net/neighbour.h:510 [inline]
 ip_finish_output2+0x874/0xb10 net/ipv4/ip_output.c:230
 __ip_finish_output net/ipv4/ip_output.c:252 [inline]
 ip_finish_output+0x2fa/0x490 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:296 [inline]
 ip_output+0xf3/0x1a0 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:448 [inline]
 ip_local_out+0x164/0x220 net/ipv4/ip_output.c:126
 __ip_queue_xmit+0x97f/0x9a0 net/ipv4/ip_output.c:533
 ip_queue_xmit+0x34/0x40 net/ipv4/ip_output.c:547
 __tcp_transmit_skb+0x140a/0x19d0 net/ipv4/tcp_output.c:1405
 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline]
 tcp_xmit_probe_skb net/ipv4/tcp_output.c:4010 [inline]
 tcp_write_wakeup+0x28f/0x810 net/ipv4/tcp_output.c:4062
 tcp_send_probe0+0x2c/0x2b0 net/ipv4/tcp_output.c:4078
 tcp_probe_timer net/ipv4/tcp_timer.c:398 [inline]
 tcp_write_timer_handler+0x394/0x520 net/ipv4/tcp_timer.c:626
 tcp_write_timer+0xb9/0x180 net/ipv4/tcp_timer.c:642
 call_timer_fn+0x2e/0x1d0 kernel/time/timer.c:1419
 expire_timers+0x135/0x250 kernel/time/timer.c:1464
 __run_timers+0x358/0x420 kernel/time/timer.c:1732
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1745
 __do_softirq+0x12c/0x26e kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x9a/0xb0 kernel/softirq.c:636
 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
 acpi_idle_do_entry drivers/acpi/processor_idle.c:553 [inline]
 acpi_idle_enter+0x258/0x2e0 drivers/acpi/processor_idle.c:688
 cpuidle_enter_state+0x2b6/0x750 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x3c/0x60 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x1a3/0x240 kernel/sched/idle.c:306
 cpu_startup_entry+0x15/0x20 kernel/sched/idle.c:403
 rest_init+0xee/0x100 init/main.c:714
 arch_call_rest_init+0xa/0xb
 start_kernel+0x5ae/0x633 init/main.c:1120
 secondary_startup_64_no_verify+0xb0/0xbb

value changed: 0x000000000000129f -> 0x00000000000012a0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W         5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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