Index: unix/tclUnixPipe.c
==================================================================
--- unix/tclUnixPipe.c
+++ unix/tclUnixPipe.c
@@ -153,10 +153,21 @@
     Tcl_DString ds;
 
     native = Tcl_UtfToExternalDString(NULL, fname, -1, &ds);
     fd = TclOSopen(native, mode, 0666);			/* INTL: Native. */
     Tcl_DStringFree(&ds);
+
+    /*
+     * Ticket [c6897e6e6a].
+     */
+
+    if (fd >= FD_SETSIZE) {
+	close(fd);
+	fd = -1;
+	errno = EMFILE;
+    }
+
     if (fd != -1) {
 	fcntl(fd, F_SETFD, FD_CLOEXEC);
 
 	/*
 	 * If the file is being opened for writing, seek to the end so we can
@@ -318,10 +329,20 @@
     int pipeIds[2];
 
     if (pipe(pipeIds) != 0) {
 	return 0;
     }
+
+    /*
+     * Ticket [c6897e6e6a].
+     */
+
+    if (pipeIds[0] >= FD_SETSIZE || pipeIds[1] >= FD_SETSIZE) {
+	close(pipeIds[0]);
+	close(pipeIds[1]);
+	return 0;
+    }
 
     fcntl(pipeIds[0], F_SETFD, FD_CLOEXEC);
     fcntl(pipeIds[1], F_SETFD, FD_CLOEXEC);
 
     *readPipe = MakeFile(pipeIds[0]);
@@ -894,13 +915,27 @@
     Tcl_Interp *interp,		/* Errors returned in result. */
     Tcl_Channel *rchan,		/* Returned read side. */
     Tcl_Channel *wchan,		/* Returned write side. */
     int flags)			/* Reserved for future use. */
 {
-    int fileNums[2];
+    int ret, fileNums[2];
+
+    ret = pipe(fileNums);
+    if (ret >= 0) {
+
+	/*
+	 * Ticket [c6897e6e6a].
+	 */
 
-    if (pipe(fileNums) < 0) {
+	if (fileNums[0] >= FD_SETSIZE || fileNums[1] >= FD_SETSIZE) {
+	    close(fileNums[0]);
+	    close(fileNums[1]);
+	    errno = EMFILE;
+	    ret = -1;
+	}
+    }
+    if (ret < 0) {
 	Tcl_SetObjResult(interp, Tcl_ObjPrintf("pipe creation failed: %s",
 		Tcl_PosixError(interp)));
 	return TCL_ERROR;
     }