diff --git a/usr.sbin/bsdinstall/distfetch/distfetch.c b/usr.sbin/bsdinstall/distfetch/distfetch.c
index c431e187799d..094929d89ea1 100644
--- a/usr.sbin/bsdinstall/distfetch/distfetch.c
+++ b/usr.sbin/bsdinstall/distfetch/distfetch.c
@@ -1,255 +1,268 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2011 Nathan Whitehorn
  * Copyright (c) 2014 Devin Teske <dteske@FreeBSD.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include <sys/param.h>
 
 #include <bsddialog.h>
 #include <ctype.h>
 #include <err.h>
 #include <errno.h>
 #include <stdio.h>
 #include <fetch.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #include "opt_osname.h"
 
 static int fetch_files(int nfiles, char **urls);
 
 int
 main(void)
 {
-	char *diststring;
+	char *diststring, *dists, *distdir, *distsite;
 	char **urls;
 	int i;
 	int ndists = 0;
 	int nfetched;
 	char error[PATH_MAX + 512];
 	struct bsddialog_conf conf;
 
-	if (getenv("DISTRIBUTIONS") == NULL)
+	if ((dists = getenv("DISTRIBUTIONS")) == NULL)
 		errx(EXIT_FAILURE, "DISTRIBUTIONS variable is not set");
 
-	diststring = strdup(getenv("DISTRIBUTIONS"));
+	if ((distdir = getenv("BSDINSTALL_DISTDIR")) == NULL)
+		errx(EXIT_FAILURE, "BSDINSTALL_DISTDIR variable is not set");
+
+	if ((distsite = getenv("BSDINSTALL_DISTSITE")) == NULL)
+		errx(EXIT_FAILURE, "BSDINSTALL_DISTSITE variable is not set");
+
+	if ((diststring = strdup(dists)) == NULL)
+		errx(EXIT_FAILURE, "Error: diststring variable out of memory!");
+
 	for (i = 0; diststring[i] != 0; i++)
 		if (isspace(diststring[i]) && !isspace(diststring[i+1]))
 			ndists++;
 	ndists++; /* Last one */
 
-	urls = calloc(ndists, sizeof(const char *));
-	if (urls == NULL) {
+	if ((urls = calloc(ndists, sizeof(char *))) == NULL) {
 		free(diststring);
 		errx(EXIT_FAILURE, "Error: distfetch URLs out of memory!");
 	}
 
 	if (bsddialog_init() == BSDDIALOG_ERROR) {
 		free(diststring);
 		errx(EXIT_FAILURE, "Error libbsddialog: %s\n",
 		    bsddialog_geterror());
 	}
 	bsddialog_initconf(&conf);
 	bsddialog_backtitle(&conf, OSNAME " Installer");
 
 	for (i = 0; i < ndists; i++) {
-		urls[i] = malloc(PATH_MAX);
+		if ((urls[i] = malloc(PATH_MAX)) == NULL) {
+			free(urls);
+			free(diststring);
+			bsddialog_end();
+			errx(EXIT_FAILURE, "Error: distfetch URLs out of memory!");
+		}
+
 		snprintf(urls[i], PATH_MAX, "%s/%s",
-		    getenv("BSDINSTALL_DISTSITE"), strsep(&diststring, " \t"));
+			 distsite, strsep(&diststring, " \t"));
 	}
 
-	if (chdir(getenv("BSDINSTALL_DISTDIR")) != 0) {
+	if (chdir(distdir) != 0) {
 		snprintf(error, sizeof(error),
-		    "Could not change to directory %s: %s\n",
-		    getenv("BSDINSTALL_DISTDIR"), strerror(errno));
+			 "Could not change to directory %s: %s\n",
+			 distdir, strerror(errno));
 		conf.title = "Error";
 		bsddialog_msgbox(&conf, error, 0, 0);
 		bsddialog_end();
 		return (EXIT_FAILURE);
 	}
 
 	nfetched = fetch_files(ndists, urls);
 
 	bsddialog_end();
 
 	free(diststring);
 	for (i = 0; i < ndists; i++) 
 		free(urls[i]);
 	free(urls);
 
 	return ((nfetched == ndists) ? EXIT_SUCCESS : EXIT_FAILURE);
 }
 
 static int
 fetch_files(int nfiles, char **urls)
 {
 	FILE *fetch_out;
 	FILE *file_out;
 	const char **minilabel;
 	int *miniperc;
 	int perc;
 	int i;
 	int last_progress;
 	int nsuccess = 0; /* Number of files successfully downloaded */
 	int progress = 0;
 	size_t chunk;
 	off_t current_bytes;
 	off_t fsize;
 	off_t total_bytes;
 	float file_perc;
 	float mainperc_file;
 	struct url_stat ustat;
 	char errormsg[PATH_MAX + 512];
 	uint8_t block[4096];
 	struct bsddialog_conf errconf;
 	struct bsddialog_conf mgconf;
 
 	/* Make the transfer list for mixedgauge */
 	minilabel = calloc(sizeof(char *), nfiles);
 	miniperc = calloc(sizeof(int), nfiles);
 	if (minilabel == NULL || miniperc == NULL)
 		errx(EXIT_FAILURE, "Error: distfetch minibars out of memory!");
 
 	for (i = 0; i < nfiles; i++) {
 		minilabel[i] = strrchr(urls[i], '/');
 		if (minilabel[i] != NULL)
 			minilabel[i]++;
 		else
 			minilabel[i] = urls[i];
 		miniperc[i] = BSDDIALOG_MG_PENDING;
 	}
 
 	bsddialog_initconf(&errconf);
 	bsddialog_infobox(&errconf, "Connecting to server.\nPlease wait...",
 	    0, 0);
 
 	/* Try to stat all the files */
 	total_bytes = 0;
 	for (i = 0; i < nfiles; i++) {
 		if (fetchStatURL(urls[i], &ustat, "") == 0 && ustat.size > 0) {
 			total_bytes += ustat.size;
 		} else {
 			total_bytes = 0;
 			break;
 		}
 	}
 
 	errconf.title = "Fetch Error";
 	errconf.clear = true;
 	bsddialog_initconf(&mgconf);
 	mgconf.title = "Fetching Distribution";
 	mgconf.auto_minwidth = 40;
 
 	mainperc_file = 100.0 / nfiles;
 	current_bytes = 0;
 	for (i = 0; i < nfiles; i++) {
 		fetchLastErrCode = 0;
 		fetch_out = fetchXGetURL(urls[i], &ustat, "");
 		if (fetch_out == NULL) {
 			snprintf(errormsg, sizeof(errormsg),
 			    "Error (URL) while fetching %s: %s\n", urls[i],
 			    fetchLastErrString);
 			miniperc[2] = BSDDIALOG_MG_FAILED;
 			bsddialog_msgbox(&errconf, errormsg, 0, 0);
 			total_bytes = 0;
 			continue;
 		}
 
 		miniperc[i] = BSDDIALOG_MG_INPROGRESS;
 		fsize = 0;
 		file_out = fopen(minilabel[i], "w+");
 		if (file_out == NULL) {
 			snprintf(errormsg, sizeof(errormsg),
 			    "Error (fopen) while fetching %s: %s\n",
 			    urls[i], strerror(errno));
 			miniperc[i] = BSDDIALOG_MG_FAILED;
 			bsddialog_msgbox(&errconf, errormsg, 0, 0);
 			fclose(fetch_out);
 			total_bytes = 0;
 			continue;
 		}
 
 		while ((chunk = fread(block, 1, sizeof(block), fetch_out))
 		    > 0) {
 			if (fwrite(block, 1, chunk, file_out) < chunk)
 				break;
 
 			current_bytes += chunk;
 			fsize += chunk;
 
 			last_progress = progress;
 			if (total_bytes > 0) {
 				progress = (current_bytes * 100) / total_bytes;
 			} else {
 				file_perc = ustat.size > 0 ?
 				    (fsize * 100) / ustat.size : 0;
 				progress = (i * mainperc_file) +
 				    ((file_perc * mainperc_file) / 100);
 			}
 
 			if (ustat.size > 0) {
 				perc = (fsize * 100) / ustat.size;
 				miniperc[i] = perc;
 			}
 
 			if (progress > last_progress) {
 				bsddialog_mixedgauge(&mgconf,
 				    "\nFetching distribution files...\n",
 				    0, 0, progress, nfiles, minilabel,
 				    miniperc);
 			}
 		}
 
 		if (ustat.size > 0 && fsize < ustat.size) {
 			if (fetchLastErrCode == 0)
 				snprintf(errormsg, sizeof(errormsg),
 				    "Error (undone) while fetching %s: %s\n",
 				    urls[i], strerror(errno));
 			else
 				snprintf(errormsg, sizeof(errormsg),
 				    "Error (libfetch) while fetching %s: %s\n",
 				    urls[i], fetchLastErrString);
 			miniperc[i] = BSDDIALOG_MG_FAILED;
 			bsddialog_msgbox(&errconf, errormsg, 0, 0);
 			total_bytes = 0;
 		} else {
 			miniperc[i] = BSDDIALOG_MG_DONE;
 			nsuccess++;
 		}
 
 		fclose(fetch_out);
 		fclose(file_out);
 	}
 
 	bsddialog_mixedgauge(&mgconf, "\nFetching distribution completed\n",
 	    0, 0, progress, nfiles, minilabel, miniperc);
 
 	free(minilabel);
 	free(miniperc);
 	return (nsuccess);
 }