Index: lib/libc/sys/recv.2
===================================================================
--- lib/libc/sys/recv.2
+++ lib/libc/sys/recv.2
@@ -332,7 +332,7 @@
 The argument
 .Fa s
 does not refer to a socket.
-.It Bq Er EMSGSIZE
+.It Bq Er EMFILE
 The
 .Fn recvmsg
 system call
@@ -340,9 +340,18 @@
 connection.
 However, the receiving program did not have enough free file
 descriptor slots to accept them.
-In this case the descriptors are
-closed, any pending data can be returned by another call to
+In this case the descriptors are closed, with pending data either discarded
+in case of unreliable datagram protocol or preserved in case of a reliable
+protocol.
+The pending data can be returned by another call to
 .Fn recvmsg .
+.It Bq Er EMSGSIZE
+The
+.Fa msg_iovlen
+member of the
+.Fa msghdr
+structure pointed to by message is less than or equal to 0, or is greater than
+.Va IOV_MAX .
 .It Bq Er EAGAIN
 The socket is marked non-blocking and the receive operation
 would block, or
Index: sys/kern/uipc_usrreq.c
===================================================================
--- sys/kern/uipc_usrreq.c
+++ sys/kern/uipc_usrreq.c
@@ -2547,9 +2547,8 @@
 
 			fdp = (int *)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
-			if (fdallocn(td, 0, fdp, newfds) != 0) {
+			if ((error = fdallocn(td, 0, fdp, newfds))) {
 				FILEDESC_XUNLOCK(fdesc);
-				error = EMSGSIZE;
 				unp_freerights(fdep, newfds);
 				m_freem(*controlp);
 				*controlp = NULL;
Index: tests/sys/kern/unix_passfd_test.c
===================================================================
--- tests/sys/kern/unix_passfd_test.c
+++ tests/sys/kern/unix_passfd_test.c
@@ -428,8 +428,8 @@
 	msghdr.msg_controllen = CMSG_LEN(sizeof(int));
 	ATF_REQUIRE(sendmsg(fd[0], &msghdr, 0) == 1);
 	ATF_REQUIRE(recvmsg(fd[1], &msghdr, 0) == -1);
-	/* Such attempt shall fail with EMSGSIZE. */
-	ATF_REQUIRE(errno == EMSGSIZE);
+	/* Such attempt shall fail with EMFILE. */
+	ATF_REQUIRE(errno == EMFILE);
 	ATF_REQUIRE(getnfds() == nfds);
 #if TEST_PROTO == SOCK_STREAM
 	/*