--- a/sys/vfs/procfs/procfs_type.c
+++ b/sys/vfs/procfs/procfs_type.c
@@ -48,19 +48,25 @@ int
 procfs_dotype(struct proc *curp, struct lwp *lp, struct pfsnode *pfs,
 	      struct uio *uio)
 {
 	struct proc *p = lp->lwp_proc;
+	const char *emul;
 	int len;
 	int error;
 	/*
 	 * buffer for emulation type
 	 */
 	char mebuffer[256];
 	char *none = "Not Available";

+	emul = (p != NULL && p->p_sysent != NULL &&
+	    p->p_sysent->sv_name != NULL) ? p->p_sysent->sv_name : none;
+
 	if (uio->uio_rw != UIO_READ)
 		return (EOPNOTSUPP);

 	if (uio->uio_offset != 0)
 		return (0);

-	if (p && p->p_sysent && p->p_sysent->sv_name) {
-		len = strlen(p->p_sysent->sv_name);
-		bcopy(p->p_sysent->sv_name, mebuffer, len);
-	} else {
-		len = strlen(none);
-		bcopy(none, mebuffer, len);
-	}
+	/*
+	 * sv_name is typically a short literal, but the sysentvec API
+	 * imposes no length limit; bound the copy to leave room for the
+	 * trailing newline so a long name cannot overflow the stack.
+	 */
+	len = strnlen(emul, sizeof(mebuffer) - 1);
+	bcopy(emul, mebuffer, len);
 	mebuffer[len++] = '\n';
 	error = uiomove(mebuffer, len, uio);
 	return error;
 }