Index: sys/compat/cloudabi/cloudabi_sock.c
===================================================================
--- sys/compat/cloudabi/cloudabi_sock.c
+++ sys/compat/cloudabi/cloudabi_sock.c
@@ -210,7 +210,7 @@
 	int error;
 
 	error = getsock_cap(td, uap->sock, cap_rights_init(&rights,
-	    CAP_GETSOCKOPT, CAP_GETPEERNAME, CAP_GETSOCKNAME), &fp, NULL);
+	    CAP_GETSOCKOPT, CAP_GETPEERNAME, CAP_GETSOCKNAME), &fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 	so = fp->f_data;
Index: sys/compat/linux/linux_socket.c
===================================================================
--- sys/compat/linux/linux_socket.c
+++ sys/compat/linux/linux_socket.c
@@ -855,7 +855,7 @@
 		if (error == EFAULT && namelen != sizeof(struct sockaddr_in))
 			return (EINVAL);
 		if (error == EINVAL) {
-			error1 = getsock_cap(td, s, &rights, &fp, NULL);
+			error1 = getsock_cap(td, s, &rights, &fp, NULL, NULL);
 			if (error1 != 0)
 				return (error1);
 			so = fp->f_data;
Index: sys/kern/kern_sendfile.c
===================================================================
--- sys/kern/kern_sendfile.c
+++ sys/kern/kern_sendfile.c
@@ -502,7 +502,7 @@
 	 * The socket must be a stream socket and connected.
 	 */
 	error = getsock_cap(td, s, cap_rights_init(&rights, CAP_SEND),
-	    sock_fp, NULL);
+	    sock_fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 	*so = (*sock_fp)->f_data;
Index: sys/kern/uipc_syscalls.c
===================================================================
--- sys/kern/uipc_syscalls.c
+++ sys/kern/uipc_syscalls.c
@@ -89,26 +89,52 @@
 /*
  * Convert a user file descriptor to a kernel file entry and check if required
  * capability rights are present.
+ * If required copy of current set of capability rights is returned.
  * A reference on the file entry is held upon returning.
  */
 int
 getsock_cap(struct thread *td, int fd, cap_rights_t *rightsp,
-    struct file **fpp, u_int *fflagp)
+    struct file **fpp, u_int *fflagp, struct filecaps *havecaps)
 {
 	struct file *fp;
+	struct filedesc *fdp;
 	int error;
-
-	error = fget_unlocked(td->td_proc->p_fd, fd, rightsp, &fp, NULL);
-	if (error != 0)
-		return (error);
-	if (fp->f_type != DTYPE_SOCKET) {
+	bool locked;
+	seq_t seq;
+
+	error = 0;
+	locked = false;
+	fdp = td->td_proc->p_fd;
+	for (;;) {
+		error = fget_unlocked(fdp, fd, rightsp, &fp, &seq);
+		if (error != 0)
+			goto out;
+		if (fp->f_type != DTYPE_SOCKET) {
+			fdrop(fp, td);
+			error = ENOTSOCK;
+			goto out;
+		}
+		if (havecaps != NULL) {
+			if (filecaps_copy(&fdp->fd_ofiles[fd].fde_caps,
+			    havecaps, locked)) {
+				fdrop(fp, td);
+				FILEDESC_SLOCK(fdp);
+				locked = true;
+				continue;
+			}
+		}
+		if (locked || !fd_modified(fdp, fd, seq))
+			break;
 		fdrop(fp, td);
-		return (ENOTSOCK);
 	}
+
 	if (fflagp != NULL)
 		*fflagp = fp->f_flag;
 	*fpp = fp;
-	return (0);
+out:
+	if (locked)
+		FILEDESC_SUNLOCK(fdp);
+	return (error);
 }
 
 /*
@@ -201,7 +227,7 @@
 	AUDIT_ARG_FD(fd);
 	AUDIT_ARG_SOCKADDR(td, dirfd, sa);
 	error = getsock_cap(td, fd, cap_rights_init(&rights, CAP_BIND),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 	so = fp->f_data;
@@ -262,7 +288,7 @@
 
 	AUDIT_ARG_FD(uap->s);
 	error = getsock_cap(td, uap->s, cap_rights_init(&rights, CAP_LISTEN),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error == 0) {
 		so = fp->f_data;
 #ifdef MAC
@@ -335,6 +361,7 @@
 	struct file *headfp, *nfp = NULL;
 	struct sockaddr *sa = NULL;
 	struct socket *head, *so;
+	struct filecaps fcaps;
 	cap_rights_t rights;
 	u_int fflag;
 	pid_t pgid;
@@ -345,7 +372,7 @@
 
 	AUDIT_ARG_FD(s);
 	error = getsock_cap(td, s, cap_rights_init(&rights, CAP_ACCEPT),
-	    &headfp, &fflag);
+	    &headfp, &fflag, &fcaps);
 	if (error != 0)
 		return (error);
 	head = headfp->f_data;
@@ -358,7 +385,8 @@
 	if (error != 0)
 		goto done;
 #endif
-	error = falloc(td, &nfp, &fd, (flags & SOCK_CLOEXEC) ? O_CLOEXEC : 0);
+	error = falloc_caps(td, &nfp, &fd,
+	    (flags & SOCK_CLOEXEC) ? O_CLOEXEC : 0, &fcaps);
 	if (error != 0)
 		goto done;
 	ACCEPT_LOCK();
@@ -467,6 +495,8 @@
 	 * a reference on nfp to the caller on success if they request it.
 	 */
 done:
+	if (nfp == NULL)
+		filecaps_free(&fcaps);
 	if (fp != NULL) {
 		if (error == 0) {
 			*fp = nfp;
@@ -545,7 +575,7 @@
 	AUDIT_ARG_FD(fd);
 	AUDIT_ARG_SOCKADDR(td, dirfd, sa);
 	error = getsock_cap(td, fd, cap_rights_init(&rights, CAP_CONNECT),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 	so = fp->f_data;
@@ -805,7 +835,7 @@
 		AUDIT_ARG_SOCKADDR(td, AT_FDCWD, mp->msg_name);
 		cap_rights_set(&rights, CAP_CONNECT);
 	}
-	error = getsock_cap(td, s, &rights, &fp, NULL);
+	error = getsock_cap(td, s, &rights, &fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 	so = (struct socket *)fp->f_data;
@@ -1006,7 +1036,7 @@
 
 	AUDIT_ARG_FD(s);
 	error = getsock_cap(td, s, cap_rights_init(&rights, CAP_RECV),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 	so = fp->f_data;
@@ -1321,7 +1351,7 @@
 
 	AUDIT_ARG_FD(uap->s);
 	error = getsock_cap(td, uap->s, cap_rights_init(&rights, CAP_SHUTDOWN),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error == 0) {
 		so = fp->f_data;
 		error = soshutdown(so, uap->how);
@@ -1395,7 +1425,7 @@
 
 	AUDIT_ARG_FD(s);
 	error = getsock_cap(td, s, cap_rights_init(&rights, CAP_SETSOCKOPT),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error == 0) {
 		so = fp->f_data;
 		error = sosetopt(so, &sopt);
@@ -1476,7 +1506,7 @@
 
 	AUDIT_ARG_FD(s);
 	error = getsock_cap(td, s, cap_rights_init(&rights, CAP_GETSOCKOPT),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error == 0) {
 		so = fp->f_data;
 		error = sogetopt(so, &sopt);
@@ -1537,7 +1567,7 @@
 
 	AUDIT_ARG_FD(fd);
 	error = getsock_cap(td, fd, cap_rights_init(&rights, CAP_GETSOCKNAME),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 	so = fp->f_data;
@@ -1636,7 +1666,7 @@
 
 	AUDIT_ARG_FD(fd);
 	error = getsock_cap(td, fd, cap_rights_init(&rights, CAP_GETPEERNAME),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 	so = fp->f_data;
Index: sys/netinet/sctp_syscalls.c
===================================================================
--- sys/netinet/sctp_syscalls.c
+++ sys/netinet/sctp_syscalls.c
@@ -248,7 +248,7 @@
 	}
 
 	AUDIT_ARG_FD(uap->sd);
-	error = getsock_cap(td, uap->sd, &rights, &fp, NULL);
+	error = getsock_cap(td, uap->sd, &rights, &fp, NULL, NULL);
 	if (error != 0)
 		goto sctp_bad;
 #ifdef KTRACE
@@ -361,7 +361,7 @@
 	}
 
 	AUDIT_ARG_FD(uap->sd);
-	error = getsock_cap(td, uap->sd, &rights, &fp, NULL);
+	error = getsock_cap(td, uap->sd, &rights, &fp, NULL, NULL);
 	if (error != 0)
 		goto sctp_bad1;
 
@@ -477,7 +477,7 @@
 
 	AUDIT_ARG_FD(uap->sd);
 	error = getsock_cap(td, uap->sd, cap_rights_init(&rights, CAP_RECV),
-	    &fp, NULL);
+	    &fp, NULL, NULL);
 	if (error != 0)
 		return (error);
 #ifdef COMPAT_FREEBSD32
Index: sys/sys/socketvar.h
===================================================================
--- sys/sys/socketvar.h
+++ sys/sys/socketvar.h
@@ -321,6 +321,7 @@
 extern so_gen_t so_gencnt;
 
 struct file;
+struct filecaps;
 struct filedesc;
 struct mbuf;
 struct sockaddr;
@@ -340,7 +341,7 @@
  */
 int	getsockaddr(struct sockaddr **namp, caddr_t uaddr, size_t len);
 int	getsock_cap(struct thread *td, int fd, cap_rights_t *rightsp,
-	    struct file **fpp, u_int *fflagp);
+	    struct file **fpp, u_int *fflagp, struct filecaps *havecaps);
 void	soabort(struct socket *so);
 int	soaccept(struct socket *so, struct sockaddr **nam);
 void	soaio_enqueue(struct task *task);