KCSAN: data-race in inet_dgram_connect / udp_lib_get

KCSAN: data-race in inet_dgram_connect / udp_lib_get_port (4)
Status: auto-closed as invalid on 2021/03/07 18:58
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 239d, last: 239d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in inet_dgram_connect / udp_lib_get_port	1	702d	702d	0/22	closed as invalid on 2019/11/19 13:44
upstream	KCSAN: data-race in inet_dgram_connect / udp_lib_get_port (2)	3	670d	675d	0/22	auto-closed as invalid on 2020/02/05 16:37
upstream	KCSAN: data-race in inet_dgram_connect / udp_lib_get_port (3)	1	326d	290d	0/22	auto-closed as invalid on 2020/12/25 11:24
upstream	KCSAN: data-race in inet_dgram_connect / udp_lib_get_port (5)	6	122d	109d	21/22	internal: reported on 2021/06/10 14:00

Sample crash report:

==================================================================
BUG: KCSAN: data-race in inet_dgram_connect / udp_lib_get_port

write to 0xffff88810e4c84ce of 2 bytes by task 19756 on cpu 0:
 udp_lib_get_port+0x4ad/0xde0 net/ipv4/udp.c:308
 udp_v4_get_port+0xde/0xf0 net/ipv4/udp.c:354
 __inet_bind+0x3eb/0x610 net/ipv4/af_inet.c:528
 inet_bind+0xac/0xe0 net/ipv4/af_inet.c:457
 __sys_bind+0x200/0x290 net/socket.c:1635
 __do_sys_bind net/socket.c:1646 [inline]
 __se_sys_bind net/socket.c:1644 [inline]
 __x64_sys_bind+0x3d/0x50 net/socket.c:1644
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88810e4c84ce of 2 bytes by task 19766 on cpu 1:
 inet_dgram_connect+0xa5/0x200 net/ipv4/af_inet.c:575
 __sys_connect_file net/socket.c:1835 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1852
 __do_sys_connect net/socket.c:1862 [inline]
 __se_sys_connect net/socket.c:1859 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1859
 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: 19766 Comm: syz-executor.0 Not tainted 5.11.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2021/01/31 18:55	upstream	6642d600b541	fc9fd31e	.config	log	report			info	KCSAN: data-race in inet_dgram_connect / udp_lib_get_port