KCSAN: data-race in netlink_insert / netlink

KCSAN: data-race in netlink_insert / netlink_sendmsg (3)
Status: auto-closed as invalid on 2021/03/06 18:35
Reported-by: syzbot+a06e7056c0085906c3ff@syzkaller.appspotmail.com
First crash: 297d, last: 176d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in netlink_insert / netlink_sendmsg (2)				2	554d	604d	0/22	auto-closed as invalid on 2020/03/28 20:50
upstream	KCSAN: data-race in netlink_insert / netlink_sendmsg				1	639d	639d	0/22	closed as invalid on 2019/11/19 13:44

Sample crash report:

==================================================================
BUG: KCSAN: data-race in netlink_insert / netlink_sendmsg

write to 0xffff888064aa7b40 of 1 bytes by task 18130 on cpu 0:
 netlink_insert+0x636/0x8e0 net/netlink/af_netlink.c:587
 netlink_autobind+0xa9/0x150 net/netlink/af_netlink.c:832
 netlink_sendmsg+0x47c/0x7c0 net/netlink/af_netlink.c:1882
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmsg+0x1ed/0x270 net/socket.c:2432
 __do_sys_sendmsg net/socket.c:2441 [inline]
 __se_sys_sendmsg net/socket.c:2439 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2439
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888064aa7b40 of 1 bytes by task 18140 on cpu 1:
 netlink_sendmsg+0x26c/0x7c0 net/netlink/af_netlink.c:1881
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmsg+0x1ed/0x270 net/socket.c:2432
 __do_sys_sendmsg net/socket.c:2441 [inline]
 __se_sys_sendmsg net/socket.c:2439 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2439
 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: 18140 Comm: syz-executor.4 Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (14):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/01/30 18:34	upstream	0e9bcda5d286	fc9fd31e	.config	log	report	info	KCSAN: data-race in netlink_insert / netlink_sendmsg
ci2-upstream-kcsan-gce	2021/01/22 06:17	upstream	83d09ad4b950	d4f4eca5	.config	log	report	info	KCSAN: data-race in netlink_insert / netlink_sendmsg
ci2-upstream-kcsan-gce	2021/01/14 20:10	upstream	65f0d2414b70	468dbb55	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/06 22:55	upstream	9f1abbe97c08	fff20c29	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/05 08:44	upstream	36bbbd0e234d	2a28ff1f	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/01 14:45	upstream	f6e1ea196492	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/25 12:52	upstream	71c5f03154ac	b982b3ea	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/12 14:34	upstream	7f376f1917d7	bca53db9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/07 22:43	upstream	cd796ed33450	51a9082e	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/16 15:23	upstream	09162bc32c88	1bf9a662	.config	log	report	info
ci2-upstream-kcsan-gce	2020/11/07 08:25	upstream	bf3e76289cd2	cba33199	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/12 02:19	upstream	3dd0130f2430	4a77ae0b	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/02 17:58	upstream	472e5b056f00	062c9832	.config	log	report	info
ci2-upstream-kcsan-gce	2020/10/01 06:27	upstream	60e720931556	a9767fb2	.config	log	report	info