KCSAN: data-race in inet6_getname / sctp_do

KCSAN: data-race in inet6_getname / sctp_do_bind (3)
Status: auto-closed as invalid on 2021/05/17 11:26
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 110d, last: 110d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in inet6_getname / sctp_do_bind (2)				1	178d	178d	0/22	auto-closed as invalid on 2021/03/10 06:45
upstream	KCSAN: data-race in inet6_getname / sctp_do_bind				2	334d	350d	0/22	auto-closed as invalid on 2020/10/05 19:48

Sample crash report:

==================================================================
BUG: KCSAN: data-race in inet6_getname / sctp_do_bind

write to 0xffff888026a9a408 of 2 bytes by task 31488 on cpu 1:
 sctp_do_bind+0x45d/0x4a0 net/sctp/socket.c:435
 sctp_bind+0x6a/0x80 net/sctp/socket.c:317
 inet6_bind+0x6a/0x160 net/ipv6/af_inet6.c:448
 __sys_bind+0x200/0x290 net/socket.c:1637
 __do_sys_bind net/socket.c:1648 [inline]
 __se_sys_bind net/socket.c:1646 [inline]
 __x64_sys_bind+0x3d/0x50 net/socket.c:1646
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888026a9a408 of 2 bytes by task 31489 on cpu 0:
 inet6_getname+0x195/0x330 net/ipv6/af_inet6.c:541
 sctp_getname+0x20/0x200 net/sctp/ipv6.c:1024
 tomoyo_socket_listen_permission+0x116/0x1c0 security/tomoyo/network.c:661
 tomoyo_socket_listen+0x11/0x20 security/tomoyo/tomoyo.c:435
 security_socket_listen+0x42/0x90 security/security.c:2144
 __sys_listen+0xe8/0x180 net/socket.c:1669
 __do_sys_listen net/socket.c:1680 [inline]
 __se_sys_listen net/socket.c:1678 [inline]
 __x64_sys_listen+0x29/0x30 net/socket.c:1678
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 31489 Comm: syz-executor.4 Tainted: G        W         5.12.0-rc6-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	2021/04/12 01:59	upstream	7d900724913c	6a81331a	.config	log	report			info	KCSAN: data-race in inet6_getname / sctp_do_bind