KCSAN: data-race in __skb_wait_for_more_packets / inet

KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown (2)
Status: auto-closed as invalid on 2020/11/11 11:35
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 390d, last: 355d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown (5)	2	99d	106d	0/22	auto-closed as invalid on 2021/07/25 13:18
upstream	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown (4)	1	144d	144d	0/22	auto-closed as invalid on 2021/06/10 09:09
upstream	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown (3)	4	235d	294d	0/22	auto-closed as invalid on 2021/03/10 20:35
upstream	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown	8	546d	684d	0/22	auto-closed as invalid on 2020/06/07 18:23

Sample crash report:

==================================================================
BUG: KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown

write to 0xffff888122c0d46a of 1 bytes by task 25495 on cpu 0:
 inet_shutdown+0x146/0x200 net/ipv4/af_inet.c:887
 __sys_shutdown net/socket.c:2204 [inline]
 __do_sys_shutdown net/socket.c:2212 [inline]
 __se_sys_shutdown+0xf2/0x140 net/socket.c:2210
 __x64_sys_shutdown+0x2d/0x40 net/socket.c:2210
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888122c0d46a of 1 bytes by task 25464 on cpu 1:
 __skb_wait_for_more_packets+0xe0/0x2a0 net/core/datagram.c:106
 __skb_recv_udp+0x6be/0x7d0 net/ipv4/udp.c:1771
 udp_recvmsg+0x134/0xa10 net/ipv4/udp.c:1801
 inet_recvmsg+0xa3/0x210 net/ipv4/af_inet.c:848
 sock_recvmsg_nosec net/socket.c:885 [inline]
 sock_recvmsg net/socket.c:903 [inline]
 __sys_recvfrom+0x1cb/0x290 net/socket.c:2049
 __do_sys_recvfrom net/socket.c:2067 [inline]
 __se_sys_recvfrom net/socket.c:2063 [inline]
 __x64_sys_recvfrom+0x74/0x90 net/socket.c:2063
 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: 25464 Comm: syz-executor.1 Not tainted 5.9.0-rc8-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	2020/10/07 11:27	upstream	c85fb28b6f99	1880b4a9	.config	log	report	info
ci2-upstream-kcsan-gce	2020/09/04 15:53	upstream	59126901f200	abf9ba4f	.config	log	report
ci2-upstream-kcsan-gce	2020/09/02 03:34	upstream	b765a32a2e91	abf9ba4f	.config	log	report