KCSAN: data-race in __inet_hash_connect / inet_send

KCSAN: data-race in __inet_hash_connect / inet_send_prepare (3)
Status: auto-closed as invalid on 2021/02/06 14:09
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 278d, last: 262d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare	2	623d	659d	0/22	auto-closed as invalid on 2020/03/17 07:16
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare (4)	7	99d	103d	21/22	internal: reported on 2021/06/10 14:00
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare (2)	1	347d	347d	0/22	auto-closed as invalid on 2020/11/12 23:57

Sample crash report:

==================================================================
BUG: KCSAN: data-race in __inet_hash_connect / inet_send_prepare

write to 0xffff88803349c1ce of 2 bytes by task 20425 on cpu 1:
 inet_bind_hash net/ipv4/inet_hashtables.c:98 [inline]
 __inet_hash_connect+0x6d1/0x860 net/ipv4/inet_hashtables.c:810
 inet6_hash_connect+0x77/0x80 net/ipv6/inet6_hashtables.c:327
 tcp_v6_connect+0xabd/0xd00 net/ipv6/tcp_ipv6.c:311
 __inet_stream_connect+0x5f1/0x710 net/ipv4/af_inet.c:661
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1191 [inline]
 tcp_sendmsg_locked+0x2036/0x2130 net/ipv4/tcp.c:1233
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1459
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:638
 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

read to 0xffff88803349c1ce of 2 bytes by task 20438 on cpu 0:
 inet_send_prepare+0x21/0x210 net/ipv4/af_inet.c:802
 inet6_sendmsg+0x29/0x80 net/ipv6/af_inet6.c:635
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x352/0x4c0 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: 0 PID: 20438 Comm: syz-executor.0 Not tainted 5.11.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info
ci2-upstream-kcsan-gce	2021/01/02 14:00	upstream	eda809aef534	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2021/01/01 05:02	upstream	f6e1ea196492	79264ae3	.config	log	report	info
ci2-upstream-kcsan-gce	2020/12/17 03:33	upstream	5e60366d56c6	04201c06	.config	log	report	info