toolchain: GCC 11.1.0
config: defconfig + kcsan.config
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BUG: KCSAN: data-race in virtqueue_get_buf_ctx_split+0x68/0x2dc

race at unknown origin, with read to 0xffff4f1d8caa74c2 of 2 bytes by task 1885 on cpu 15:
 virtqueue_get_buf_ctx_split+0x68/0x2dc
 virtqueue_get_buf+0x58/0x70
 virtnet_send_command+0x1a8/0x234
 virtnet_set_rx_mode+0x150/0x420
 __dev_set_rx_mode+0x9c/0x100
 __dev_open+0x1e4/0x294
 __dev_change_flags+0x264/0x310
 dev_change_flags+0x5c/0xbc
 do_setlink+0x38c/0x1464
 rtnl_setlink+0x118/0x1cc
 rtnetlink_rcv_msg+0x198/0x490
 netlink_rcv_skb+0x78/0x190
 rtnetlink_rcv+0x1c/0x30
 netlink_unicast+0x3a0/0x3f0
 netlink_sendmsg+0x2e0/0x5bc
 __sys_sendto+0x15c/0x22c
 __arm64_sys_sendto+0x7c/0xa0
 invoke_syscall+0x60/0x180
 el0_svc_common.constprop.0+0x128/0x160
 do_el0_svc+0x8c/0xb0
 el0_svc+0x3c/0x80
 el0t_64_sync_handler+0xa8/0x130
 el0t_64_sync+0x1a0/0x1a4

value changed: 0x0001 -> 0x0002

Reported by Kernel Concurrency Sanitizer on:
CPU: 15 PID: 1885 Comm: systemd-network Not tainted 5.16.0-rc4-00002-g58b9ffdc5dc3 #1
Hardware name: linux,dummy-virt (DT)
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