KCSAN: data-race in unix_dgram_connect / unix_dgram

KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (4)
Status: auto-closed as invalid on 2021/06/27 09:27
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 141d, last: 125d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in unix_dgram_connect / unix_dgram_poll	5	429d	459d	0/22	auto-closed as invalid on 2020/08/27 17:47
upstream	KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (3)	4	206d	250d	0/22	auto-closed as invalid on 2021/04/07 19:26
upstream	KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (5)	1	43d	43d	0/22	auto-closed as invalid on 2021/09/17 19:26
upstream	KCSAN: data-race in unix_dgram_connect / unix_dgram_poll (2)	3	311d	288d	0/22	auto-closed as invalid on 2020/12/25 10:44

Sample crash report:

==================================================================
BUG: KCSAN: data-race in unix_dgram_connect / unix_dgram_poll

write to 0xffff888149264a30 of 4 bytes by task 17725 on cpu 1:
 unix_dgram_disconnected net/unix/af_unix.c:486 [inline]
 unix_dgram_connect+0x73d/0x850 net/unix/af_unix.c:1191
 __sys_connect_file net/socket.c:1837 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1854
 __do_sys_connect net/socket.c:1864 [inline]
 __se_sys_connect net/socket.c:1861 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1861
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888149264a30 of 4 bytes by task 17720 on cpu 0:
 unix_dgram_poll+0x6e/0x3e0 net/unix/af_unix.c:2693
 sock_poll+0x23e/0x260 net/socket.c:1246
 vfs_poll include/linux/poll.h:90 [inline]
 do_pollfd fs/select.c:869 [inline]
 do_poll fs/select.c:917 [inline]
 do_sys_poll+0x622/0xc40 fs/select.c:1011
 __do_sys_ppoll fs/select.c:1117 [inline]
 __se_sys_ppoll+0x169/0x1b0 fs/select.c:1097
 __x64_sys_ppoll+0x63/0x70 fs/select.c:1097
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17720 Comm: syz-executor.4 Tainted: G        W         5.13.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2021/05/23 09:21	upstream	4d7620341eda	3c7fef33	.config	log	report			info	KCSAN: data-race in unix_dgram_connect / unix_dgram_poll
ci2-upstream-kcsan-gce	2021/05/07 22:38	upstream	1ad77a05cfae	bc5434be	.config	log	report			info	KCSAN: data-race in unix_dgram_connect / unix_dgram_poll