toolchain: LLVM 11.0.0
config: defconfig + kcsan.config
==================================================================
BUG: KCSAN: data-race in virtqueue_get_buf_ctx+0xe8/0x458

race at unknown origin, with read to 0xffff4518d34fc4c2 of 2 bytes by task 1882 on cpu 8:
 virtqueue_get_buf_ctx+0xe8/0x458
 virtqueue_get_buf+0x14/0x20
 virtnet_send_command+0x1a8/0x250
 virtnet_set_rx_mode+0x12c/0x3ac
 __dev_set_rx_mode+0xd4/0xe8
 dev_mc_add+0x90/0xb4
 igmp_group_added+0xc0/0x2fc
 ____ip_mc_inc_group+0x32c/0x3e8
 ip_mc_up+0x9c/0x110
 inetdev_event+0x23c/0x79c
 raw_notifier_call_chain+0x60/0x90
 __dev_notify_flags+0x124/0x274
 dev_change_flags+0x90/0xb0
 do_setlink+0x4f4/0x1424
 rtnl_setlink+0x18c/0x1c0
 rtnetlink_rcv_msg+0x328/0x518
 netlink_rcv_skb+0x174/0x198
 rtnetlink_rcv+0x18/0x24
 netlink_unicast_kernel+0x148/0x1f0
 netlink_unicast+0x110/0x1cc
 netlink_sendmsg+0x37c/0x458
 __sys_sendto+0x174/0x1e8
 __arm64_sys_sendto+0x78/0x94
 invoke_syscall+0x54/0x160
 el0_svc_common+0xc0/0x148
 do_el0_svc+0x38/0xa8
 el0_svc+0x20/0x50
 el0t_64_sync_handler+0x68/0xac
 el0t_64_sync+0x180/0x184
  
value changed: 0x0004 -> 0x0005
  
Reported by Kernel Concurrency Sanitizer on:
CPU: 8 PID: 1882 Comm: systemd-network Not tainted 5.16.0-rc4-00002-g5854738642b4 #1
Hardware name: linux,dummy-virt (DT)
==================================================================