syzbot

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BUG: KCSAN: data-race in sock_set_timestamping / udpv6_sendmsg

write to 0xffff888100896d28 of 2 bytes by task 15220 on cpu 0:
 sock_set_timestamping+0x197/0x4b0 net/core/sock.c:882
 sock_setsockopt+0x17b6/0x1d50 net/core/sock.c:1134
 __sys_setsockopt+0x14f/0x200 net/socket.c:2155
 __do_sys_setsockopt net/socket.c:2170 [inline]
 __se_sys_setsockopt net/socket.c:2167 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2167
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888100896d28 of 2 bytes by task 15221 on cpu 1:
 udpv6_sendmsg+0x18c/0x16b0 net/ipv6/udp.c:1313
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:642
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg net/socket.c:723 [inline]
 __sys_sendto+0x2a8/0x370 net/socket.c:2019
 __do_sys_sendto net/socket.c:2031 [inline]
 __se_sys_sendto net/socket.c:2027 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2027
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0x0044

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15221 Comm: syz-executor.1 Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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