KCSAN: data-race in dev_get_tstats64 / wg_packet_handshake_receive

KCSAN: data-race in dev_get_tstats64 / wg_packet_handshake_receive_worker
Status: auto-closed as invalid on 2021/02/26 04:57
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 197d, last: 189d

Sample crash report:

==================================================================
BUG: KCSAN: data-race in dev_get_tstats64 / wg_packet_handshake_receive_worker

read-write to 0xffffe8ffffc7e2c8 of 8 bytes by task 9222 on cpu 0:
 update_rx_stats drivers/net/wireguard/receive.c:27 [inline]
 wg_receive_handshake_packet drivers/net/wireguard/receive.c:205 [inline]
 wg_packet_handshake_receive_worker+0x37c/0x440 drivers/net/wireguard/receive.c:220
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x635/0xb90 kernel/workqueue.c:2421
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffffe8ffffc7e2c8 of 8 bytes by task 8478 on cpu 1:
 dev_fetch_sw_netstats net/core/dev.c:10439 [inline]
 dev_get_tstats64+0xe6/0x1a0 net/core/dev.c:10463
 dev_get_stats+0x63/0x160 net/core/dev.c:10405
 rtnl_fill_stats+0x45/0x320 net/core/rtnetlink.c:1211
 rtnl_fill_ifinfo+0xe92/0x2430 net/core/rtnetlink.c:1783
 rtmsg_ifinfo_build_skb+0xa2/0x130 net/core/rtnetlink.c:3798
 rtmsg_ifinfo_event net/core/rtnetlink.c:3830 [inline]
 rtmsg_ifinfo+0x55/0xc0 net/core/rtnetlink.c:3839
 __dev_notify_flags+0x63/0x3a0 net/core/dev.c:8512
 dev_change_flags+0xa2/0xc0 net/core/dev.c:8554
 do_setlink+0x741/0x21d0 net/core/rtnetlink.c:2708
 __rtnl_newlink net/core/rtnetlink.c:3376 [inline]
 rtnl_newlink+0xe58/0x12f0 net/core/rtnetlink.c:3491
 rtnetlink_rcv_msg+0x723/0x7c0 net/core/rtnetlink.c:5553
 netlink_rcv_skb+0x13e/0x240 net/netlink/af_netlink.c:2494
 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5571
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x5df/0x6b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x6f8/0x7c0 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 __sys_sendto+0x2a8/0x370 net/socket.c:1975
 __do_sys_sendto net/socket.c:1987 [inline]
 __se_sys_sendto net/socket.c:1983 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:1983
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8478 Comm: syz-executor.5 Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2021/01/22 04:55	upstream	83d09ad4b950	d4f4eca5	.config	log	report			info	KCSAN: data-race in dev_get_tstats64 / wg_packet_handshake_receive_worker
ci2-upstream-kcsan-gce	2021/01/14 11:32	upstream	65f0d2414b70	269d24e8	.config	log	report			info