syzbot

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BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg

read to 0xffff8880a3f31320 of 8 bytes by task 13703 on cpu 0:
 netlink_recvmsg+0xf3/0x910 net/netlink/af_netlink.c:1964
 sock_recvmsg_nosec net/socket.c:873 [inline]
 sock_recvmsg net/socket.c:891 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:887
 __sys_recvfrom+0x1ae/0x2d0 net/socket.c:2042
 __do_sys_recvfrom net/socket.c:2060 [inline]
 __se_sys_recvfrom net/socket.c:2056 [inline]
 __x64_sys_recvfrom+0x89/0xb0 net/socket.c:2056
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880a3f31320 of 8 bytes by task 13707 on cpu 1:
 netlink_recvmsg+0x124/0x910 net/netlink/af_netlink.c:1965
 sock_recvmsg_nosec net/socket.c:873 [inline]
 ____sys_recvmsg+0x387/0x3a0 net/socket.c:2551
 ___sys_recvmsg+0xb2/0x100 net/socket.c:2595
 do_recvmmsg+0x19a/0x5c0 net/socket.c:2693
 __sys_recvmmsg+0x1ef/0x200 net/socket.c:2772
 __do_sys_recvmmsg net/socket.c:2795 [inline]
 __se_sys_recvmmsg net/socket.c:2788 [inline]
 __x64_sys_recvmmsg+0x89/0xb0 net/socket.c:2788
 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: 13707 Comm: syz-executor.0 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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