KCSAN: data-race in __skb_wait_for_more_packets / inet

KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown (4)
Status: auto-closed as invalid on 2021/06/10 09:09
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 85d, last: 85d

similar bugs (4):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown (5)	2	39d	47d	0/22	auto-closed as invalid on 2021/07/25 13:18
upstream	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown (3)	4	176d	234d	0/22	auto-closed as invalid on 2021/03/10 20:35
upstream	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown (2)	3	295d	331d	0/22	auto-closed as invalid on 2020/11/11 11:35
upstream	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown	8	487d	624d	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 0xffff888100c4efaa of 1 bytes by task 7457 on cpu 1:
 inet_shutdown+0x148/0x200 net/ipv4/af_inet.c:891
 __sys_shutdown_sock net/socket.c:2189 [inline]
 __sys_shutdown net/socket.c:2201 [inline]
 __do_sys_shutdown net/socket.c:2209 [inline]
 __se_sys_shutdown+0xf6/0x140 net/socket.c:2207
 __x64_sys_shutdown+0x2d/0x40 net/socket.c:2207
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888100c4efaa of 1 bytes by task 7456 on cpu 0:
 __skb_wait_for_more_packets+0xdd/0x2e0 net/core/datagram.c:106
 __skb_recv_udp+0x761/0x890 net/ipv4/udp.c:1776
 udp_recvmsg+0x155/0xa40 net/ipv4/udp.c:1835
 inet_recvmsg+0xa3/0x200 net/ipv4/af_inet.c:852
 sock_recvmsg_nosec net/socket.c:888 [inline]
 sock_recvmsg net/socket.c:906 [inline]
 __sys_recvfrom+0x1d7/0x2a0 net/socket.c:2034
 __do_sys_recvfrom net/socket.c:2052 [inline]
 __se_sys_recvfrom net/socket.c:2048 [inline]
 __x64_sys_recvfrom+0x74/0x90 net/socket.c:2048
 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: 7456 Comm: syz-executor.5 Not tainted 5.12.0-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	2021/05/06 09:07	upstream	a79cdfba68a1	06c27ff5	.config	log	report			info	KCSAN: data-race in __skb_wait_for_more_packets / inet_shutdown