KCSAN: data-race in __inet_hash_connect / inet_send

KCSAN: data-race in __inet_hash_connect / inet_send_prepare (4)
Status: internal: reported on 2021/06/10 14:00
Reported-by: syzbot+@syzkaller.appspotmail.com
Fix commit: dcd01eeac144 inet: annotate data race in inet_send_prepare() and inet_dgram_connect()
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce ci-upstream-kmsan-gce-386 ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-arm32]
First crash: 104d, last: 48d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare	2	571d	607d	0/22	auto-closed as invalid on 2020/03/17 07:16
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare (2)	1	296d	296d	0/22	auto-closed as invalid on 2020/11/12 23:57
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare (3)	3	210d	226d	0/22	auto-closed as invalid on 2021/02/06 14:09

Sample crash report:

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

write to 0xffff888107c2e98e of 2 bytes by task 18238 on cpu 1:
 inet_bind_hash net/ipv4/inet_hashtables.c:98 [inline]
 __inet_hash_connect+0x716/0x900 net/ipv4/inet_hashtables.c:829
 inet6_hash_connect+0x77/0x80 net/ipv6/inet6_hashtables.c:327
 tcp_v6_connect+0x983/0xbb0 net/ipv6/tcp_ipv6.c:311
 __inet_stream_connect+0x156/0x6d0 net/ipv4/af_inet.c:664
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1190 [inline]
 tcp_sendmsg_locked+0x22e9/0x23f0 net/ipv4/tcp.c:1232
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1458
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888107c2e98e of 2 bytes by task 18239 on cpu 0:
 inet_send_prepare+0x21/0x210 net/ipv4/af_inet.c:806
 inet6_sendmsg+0x29/0x80 net/ipv6/af_inet6.c:639
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg net/socket.c:674 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2350
 ___sys_sendmsg net/socket.c:2404 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2490
 __do_sys_sendmmsg net/socket.c:2519 [inline]
 __se_sys_sendmmsg net/socket.c:2516 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2516
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0xbb7c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18239 Comm: syz-executor.3 Not tainted 5.13.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (7):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-upstream-kcsan-gce	2021/06/13 16:35	upstream	8ecfa36cd4db	1ba81399	.config	log	report	info	KCSAN: data-race in __inet_hash_connect / inet_send_prepare
ci2-upstream-kcsan-gce	2021/06/09 14:36	upstream	368094df48e6	84fe5d96	.config	log	report	info	KCSAN: data-race in __inet_hash_connect / inet_send_prepare
ci2-upstream-kcsan-gce	2021/06/07 17:09	upstream	614124bea77e	e59537be	.config	log	report	info	KCSAN: data-race in __inet_hash_connect / inet_send_prepare
ci2-upstream-kcsan-gce	2021/05/26 03:42	upstream	a050a6d2b7e8	93d3a9f6	.config	log	report	info	KCSAN: data-race in __inet_hash_connect / inet_send_prepare
ci2-upstream-kcsan-gce	2021/04/21 05:39	upstream	1fe5501ba1ab	c0ced557	.config	log	report	info	KCSAN: data-race in __inet_hash_connect / inet_send_prepare
ci2-upstream-kcsan-gce	2021/04/20 00:35	upstream	7af08140979a	4285c989	.config	log	report	info	KCSAN: data-race in __inet_hash_connect / inet_send_prepare
ci2-upstream-kcsan-gce	2021/04/18 23:53	upstream	bf05bf16c76b	7e2b734b	.config	log	report	info	KCSAN: data-race in __inet_hash_connect / inet_send_prepare