syzbot

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BUG: KCSAN: data-race in __ip4_datagram_connect / skb_set_owner_w

write to 0xffff888043ca120c of 4 bytes by task 30434 on cpu 0:
 sk_set_txhash include/net/sock.h:1921 [inline]
 __ip4_datagram_connect+0x722/0x790 net/ipv4/datagram.c:75
 __ip6_datagram_connect+0x559/0x900 net/ipv6/datagram.c:189
 ip6_datagram_connect+0x2a/0x40 net/ipv6/datagram.c:272
 inet_dgram_connect+0x115/0x200 net/ipv4/af_inet.c:577
 __sys_connect_file net/socket.c:1835 [inline]
 __sys_connect+0x245/0x280 net/socket.c:1852
 __do_sys_connect net/socket.c:1862 [inline]
 __se_sys_connect net/socket.c:1859 [inline]
 __x64_sys_connect+0x3d/0x50 net/socket.c:1859
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888043ca120c of 4 bytes by task 30440 on cpu 1:
 skb_set_hash_from_sk include/net/sock.h:2188 [inline]
 skb_set_owner_w+0x10d/0x210 net/core/sock.c:2087
 sock_alloc_send_pskb+0x452/0x4e0 net/core/sock.c:2351
 sock_alloc_send_skb+0x2d/0x40 net/core/sock.c:2365
 __ip6_append_data+0x1758/0x2080 net/ipv6/ip6_output.c:1581
 ip6_make_skb+0x258/0x420 net/ipv6/ip6_output.c:1944
 udpv6_sendmsg+0x1544/0x17e0 net/ipv6/udp.c:1527
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:638
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x352/0x4c0 net/socket.c:2345
 ___sys_sendmsg net/socket.c:2399 [inline]
 __sys_sendmmsg+0x335/0x4b0 net/socket.c:2489
 __do_sys_sendmmsg net/socket.c:2518 [inline]
 __se_sys_sendmmsg net/socket.c:2515 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2515
 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: 30440 Comm: syz-executor.0 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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