--- orig-linux_socket.c	2021-11-08 00:00:00 +0000
+++ work-linux_socket.c	2021-11-09 00:00:00 +0000
@@ -890,11 +890,49 @@
 	    UIO_USERSPACE));
 }
 
+static int
+linux_sa_put(struct osockaddr *osa)
+{
+	struct osockaddr sa;
+	int error, bdom;
+
+	/*
+	 * Only read/write the osockaddr family part, the rest is
+	 * not changed.
+	 */
+	error = copyin(osa, &sa, sizeof(sa.sa_family));
+	if (error != 0)
+		return (error);
+
+	bdom = bsd_to_linux_domain(sa.sa_family);
+	if (bdom == -1)
+		return (EINVAL);
+
+	sa.sa_family = bdom;
+	return (copyout(&sa, osa, sizeof(sa.sa_family)));
+}
+
+static int
+old_bsd_to_linux_sockaddr(struct sockaddr *arg)
+{
+	struct sockaddr sa;
+	size_t sa_len = sizeof(struct sockaddr);
+	int error, bdom;
+
+	if ((error = copyin(arg, &sa, sa_len)))
+		return (error);
+
+	bdom = bsd_to_linux_domain(sa.sa_family);
+	if (bdom == -1)
+		return (EAFNOSUPPORT);
+
+	*(u_short *)&sa = bdom;
+	return (copyout(&sa, arg, sa_len));
+}
+
 int
 linux_recvfrom(struct thread *td, struct linux_recvfrom_args *args)
 {
-	struct l_sockaddr *lsa;
-	struct sockaddr *sa;
 	struct msghdr msg;
 	struct iovec aiov;
 	int error, fromlen;
@@ -906,14 +944,11 @@
 			return (error);
 		if (fromlen < 0)
 			return (EINVAL);
-		sa = malloc(fromlen, M_SONAME, M_WAITOK);
-	} else {
-		fromlen = 0;
-		sa = NULL;
-	}
+		msg.msg_namelen = fromlen;
+	} else
+		msg.msg_namelen = 0;
 
-	msg.msg_name = sa;
-	msg.msg_namelen = fromlen;
+	msg.msg_name = (struct sockaddr * __restrict)PTRIN(args->from);
 	msg.msg_iov = &aiov;
 	msg.msg_iovlen = 1;
 	aiov.iov_base = PTRIN(args->buf);
@@ -921,23 +956,23 @@
 	msg.msg_control = 0;
 	msg.msg_flags = linux_to_bsd_msg_flags(args->flags);
 
-	error = kern_recvit(td, args->s, &msg, UIO_SYSSPACE, NULL);
+	error = kern_recvit(td, args->s, &msg, UIO_USERSPACE, NULL);
 	if (error != 0)
-		goto out;
+		return (error);
 
 	if (PTRIN(args->from) != NULL) {
-		error = bsd_to_linux_sockaddr(sa, &lsa, msg.msg_namelen);
-		if (error == 0)
-			error = copyout(lsa, PTRIN(args->from),
-			    msg.msg_namelen);
-		free(lsa, M_SONAME);
+		error = old_bsd_to_linux_sockaddr((struct sockaddr *)PTRIN(args->from));
+		if (error != 0)
+			return (error);
+
+		error = linux_sa_put((struct osockaddr *)
+		    PTRIN(args->from));
 	}
 
-	if (error == 0 && PTRIN(args->fromlen) != NULL)
+	if (PTRIN(args->fromlen) != NULL)
 		error = copyout(&msg.msg_namelen, PTRIN(args->fromlen),
 		    sizeof(msg.msg_namelen));
-out:
-	free(sa, M_SONAME);
+
 	return (error);
 }