KCSAN: data-race in inet_send_prepare / sctp_get_port

KCSAN: data-race in inet_send_prepare / sctp_get_port_local
Status: auto-closed as invalid on 2020/01/26 16:46
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 677d, last: 677d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in inet_send_prepare / sctp_get_port_local (3)	2	372d	403d	0/22	auto-closed as invalid on 2020/10/22 02:42
upstream	KCSAN: data-race in inet_send_prepare / sctp_get_port_local (2)	1	451d	451d	0/22	auto-closed as invalid on 2020/08/04 21:16
upstream	KCSAN: data-race in inet_send_prepare / sctp_get_port_local (5)	3	164d	205d	0/22	auto-closed as invalid on 2021/05/18 14:42
upstream	KCSAN: data-race in inet_send_prepare / sctp_get_port_local (4)	3	255d	287d	0/22	auto-closed as invalid on 2021/02/16 22:07

Sample crash report:

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

write to 0xffff88809e0b368e of 2 bytes by task 12270 on cpu 0:
 sctp_get_port_local+0x962/0xba0 net/sctp/socket.c:8305
 sctp_do_bind+0x165/0x360 net/sctp/socket.c:402
 sctp_autobind+0x9f/0xd0 net/sctp/socket.c:8587
 sctp_connect_new_asoc+0x2d2/0x360 net/sctp/socket.c:1061
 sctp_sendmsg_new_asoc net/sctp/socket.c:1680 [inline]
 sctp_sendmsg+0xe31/0x14e0 net/sctp/socket.c:1990
 inet_sendmsg+0x6d/0x90 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 __sys_sendto+0x21f/0x320 net/socket.c:1952
 __do_sys_sendto net/socket.c:1964 [inline]
 __se_sys_sendto net/socket.c:1960 [inline]
 __x64_sys_sendto+0x89/0xb0 net/socket.c:1960
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809e0b368e of 2 bytes by task 12275 on cpu 1:
 inet_send_prepare+0x4a/0x200 net/ipv4/af_inet.c:792
 inet_sendmsg+0x37/0x90 net/ipv4/af_inet.c:804
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 __sys_sendto+0x21f/0x320 net/socket.c:1952
 __do_sys_sendto net/socket.c:1964 [inline]
 __se_sys_sendto net/socket.c:1960 [inline]
 __x64_sys_sendto+0x89/0xb0 net/socket.c:1960
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12275 Comm: syz-executor.1 Not tainted 5.4.0-rc7+ #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	2019/11/17 16:38	https://github.com/google/ktsan.git kcsan	5863cc791e4c	d5696d51	.config	log	report