syzbot

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BUG: KCSAN: data-race in netlink_insert / netlink_sendmsg

read to 0xffff8880a0447340 of 1 bytes by task 32386 on cpu 0:
 netlink_sendmsg+0x28f/0x8b0 net/netlink/af_netlink.c:1879
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:659
 ____sys_sendmsg+0x212/0x4d0 net/socket.c:2330
 ___sys_sendmsg+0xb5/0x100 net/socket.c:2384
 __sys_sendmmsg+0x123/0x350 net/socket.c:2474
 __do_sys_sendmmsg net/socket.c:2503 [inline]
 __se_sys_sendmmsg net/socket.c:2500 [inline]
 __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2500
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880a0447340 of 1 bytes by task 32336 on cpu 1:
 netlink_insert+0x4b7/0xa00 net/netlink/af_netlink.c:586
 netlink_autobind.isra.0+0xf8/0x170 net/netlink/af_netlink.c:831
 netlink_bind+0x2e1/0x690 net/netlink/af_netlink.c:1034
 __sys_bind+0x1df/0x220 net/socket.c:1649
 __do_sys_bind net/socket.c:1660 [inline]
 __se_sys_bind net/socket.c:1658 [inline]
 __x64_sys_bind+0x4c/0x60 net/socket.c:1658
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 32336 Comm: syz-executor.2 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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