diff --git a/src/net/unixsock_posix.go b/src/net/unixsock_posix.go
index 0306b5989b..99a89c827b 100644
--- a/src/net/unixsock_posix.go
+++ b/src/net/unixsock_posix.go
@@ -114,7 +114,7 @@ func (c *UnixConn) readFrom(b []byte) (int, *UnixAddr, error) {
 func (c *UnixConn) readMsg(b, oob []byte) (n, oobn, flags int, addr *UnixAddr, err error) {
 	var sa syscall.Sockaddr
 	n, oobn, flags, sa, err = c.fd.readMsg(b, oob, readMsgFlags)
-	if oobn > 0 {
+	if readMsgFlags == 0 && err == nil && oobn > 0 {
 		setReadMsgCloseOnExec(oob[:oobn])
 	}
 
diff --git a/src/net/unixsock_readmsg_posix.go b/src/net/unixsock_readmsg_cloexec.go
similarity index 78%
rename from src/net/unixsock_readmsg_posix.go
rename to src/net/unixsock_readmsg_cloexec.go
index 07d7df5e66..716484cc6c 100644
--- a/src/net/unixsock_readmsg_posix.go
+++ b/src/net/unixsock_readmsg_cloexec.go
@@ -2,14 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build aix || darwin || dragonfly || freebsd || netbsd || openbsd || solaris
-// +build aix darwin dragonfly freebsd netbsd openbsd solaris
+//go:build aix || darwin || freebsd || solaris
+// +build aix darwin freebsd solaris
 
 package net
 
-import (
-	"syscall"
-)
+import "syscall"
 
 const readMsgFlags = 0
 
diff --git a/src/net/unixsock_readmsg_linux.go b/src/net/unixsock_readmsg_cmsg_cloexec.go
similarity index 59%
rename from src/net/unixsock_readmsg_linux.go
rename to src/net/unixsock_readmsg_cmsg_cloexec.go
index 3296681017..bb851b89c0 100644
--- a/src/net/unixsock_readmsg_linux.go
+++ b/src/net/unixsock_readmsg_cmsg_cloexec.go
@@ -2,16 +2,13 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build linux
-// +build linux
+//go:build dragonfly || linux || netbsd || openbsd
+// +build dragonfly linux netbsd openbsd
 
 package net
 
-import (
-	"syscall"
-)
+import "syscall"
 
 const readMsgFlags = syscall.MSG_CMSG_CLOEXEC
 
-func setReadMsgCloseOnExec(oob []byte) {
-}
+func setReadMsgCloseOnExec(oob []byte) {}
diff --git a/src/net/unixsock_readmsg_other.go b/src/net/unixsock_readmsg_other.go
index c8db657cd6..329076183a 100644
--- a/src/net/unixsock_readmsg_other.go
+++ b/src/net/unixsock_readmsg_other.go
@@ -9,5 +9,4 @@ package net
 
 const readMsgFlags = 0
 
-func setReadMsgCloseOnExec(oob []byte) {
-}
+func setReadMsgCloseOnExec(oob []byte) {}
diff --git a/src/syscall/zerrors_dragonfly_amd64.go b/src/syscall/zerrors_dragonfly_amd64.go
index b572f44a6b..8ed611b3e4 100644
--- a/src/syscall/zerrors_dragonfly_amd64.go
+++ b/src/syscall/zerrors_dragonfly_amd64.go
@@ -850,6 +850,7 @@ const (
 	MAP_VPAGETABLE                    = 0x2000
 	MCL_CURRENT                       = 0x1
 	MCL_FUTURE                        = 0x2
+	MSG_CMSG_CLOEXEC                  = 0x1000
 	MSG_CTRUNC                        = 0x20
 	MSG_DONTROUTE                     = 0x4
 	MSG_DONTWAIT                      = 0x80
diff --git a/src/syscall/zerrors_openbsd_386.go b/src/syscall/zerrors_openbsd_386.go
index 04d1b3f177..a8457c6edf 100644
--- a/src/syscall/zerrors_openbsd_386.go
+++ b/src/syscall/zerrors_openbsd_386.go
@@ -891,6 +891,7 @@ const (
 	MCL_CURRENT                       = 0x1
 	MCL_FUTURE                        = 0x2
 	MSG_BCAST                         = 0x100
+	MSG_CMSG_CLOEXEC                  = 0x800
 	MSG_CTRUNC                        = 0x20
 	MSG_DONTROUTE                     = 0x4
 	MSG_DONTWAIT                      = 0x80
diff --git a/src/syscall/zerrors_openbsd_amd64.go b/src/syscall/zerrors_openbsd_amd64.go
index 923a3a47c5..eb19537a2a 100644
--- a/src/syscall/zerrors_openbsd_amd64.go
+++ b/src/syscall/zerrors_openbsd_amd64.go
@@ -891,6 +891,7 @@ const (
 	MCL_CURRENT                       = 0x1
 	MCL_FUTURE                        = 0x2
 	MSG_BCAST                         = 0x100
+	MSG_CMSG_CLOEXEC                  = 0x800
 	MSG_CTRUNC                        = 0x20
 	MSG_DONTROUTE                     = 0x4
 	MSG_DONTWAIT                      = 0x80