==================================================================
BUG: KCSAN: data-race in ip_tunnel_xmit / ip_tunnel_xmit

read-write to 0xffff888136b82158 of 8 bytes by task 2167 on cpu 0:
 ip_tunnel_xmit+0x9e1/0x11c0 net/ipv4/ip_tunnel.c:820
 __gre_xmit net/ipv4/ip_gre.c:469 [inline]
 ipgre_xmit+0x525/0x570 net/ipv4/ip_gre.c:657
 __netdev_start_xmit include/linux/netdevice.h:4775 [inline]
 netdev_start_xmit include/linux/netdevice.h:4789 [inline]
 __dev_direct_xmit+0x323/0x4b0 net/core/dev.c:4244
 dev_direct_xmit include/linux/netdevice.h:2943 [inline]
 packet_direct_xmit+0xeb/0x1a0 net/packet/af_packet.c:282
 packet_snd net/packet/af_packet.c:3063 [inline]
 packet_sendmsg+0x20c3/0x2930 net/packet/af_packet.c:3094
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmmsg+0x27c/0x4a0 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read-write to 0xffff888136b82158 of 8 bytes by task 2168 on cpu 1:
 ip_tunnel_xmit+0x9e1/0x11c0 net/ipv4/ip_tunnel.c:820
 __gre_xmit net/ipv4/ip_gre.c:469 [inline]
 ipgre_xmit+0x525/0x570 net/ipv4/ip_gre.c:657
 __netdev_start_xmit include/linux/netdevice.h:4775 [inline]
 netdev_start_xmit include/linux/netdevice.h:4789 [inline]
 __dev_direct_xmit+0x323/0x4b0 net/core/dev.c:4244
 dev_direct_xmit include/linux/netdevice.h:2943 [inline]
 packet_direct_xmit+0xeb/0x1a0 net/packet/af_packet.c:282
 packet_snd net/packet/af_packet.c:3063 [inline]
 packet_sendmsg+0x20c3/0x2930 net/packet/af_packet.c:3094
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg net/socket.c:725 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2413
 ___sys_sendmsg net/socket.c:2467 [inline]
 __sys_sendmmsg+0x27c/0x4a0 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000003dce -> 0x0000000000003dd1

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2168 Comm: syz-executor.1 Not tainted 5.18.0-rc6-syzkaller-00161-gbc403203d65a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================