net: Set fput_needed iff FDPUT_FPUT is set

BugLink: https://bugs.launchpad.net/bugs/1892822

[ Upstream commit ce787a5a ]

We should fput() file iff FDPUT_FPUT is set. So we should set fput_needed
accordingly.

Fixes: 00e188ef ("sockfd_lookup_light(): switch to fdget^W^Waway from fget_light")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

net/socket.c

@@ -456,7 +456,7 @@ static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
 	if (f.file) {
 		sock = sock_from_file(f.file, err);
 		if (likely(sock)) {
-			*fput_needed = f.flags;
+			*fput_needed = f.flags & FDPUT_FPUT;
 			return sock;
 		}
 		fdput(f);