pledge() won't work but we can use unveil() to reduce filesystem access

in these 3 related programs (they borrow parts of each other using .PATH)
Hopefully no regressions, ktrace checks by myself and mestre

3 files changed, 25 insertions, 10 deletions

diff --git a/usr.bin/systat/main.c b/usr.bin/systat/main.c
index 7df80a19c3a..09e9f77506b 100644
--- a/usr.bin/systat/main.c
+++ b/usr.bin/systat/main.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: main.c,v 1.70 2019/06/28 13:35:04 deraadt Exp $	 */
+/* $OpenBSD: main.c,v 1.71 2019/10/14 19:22:17 deraadt Exp $	 */
 /*
  * Copyright (c) 2001, 2007 Can Erkin Acar
  * Copyright (c) 2001 Daniel Hartmeier
@@ -526,6 +526,11 @@ main(int argc, char *argv[])
 
 	setup_term(maxlines);
 
+	if (unveil("/", "r") == -1)
+		err(1, "unveil");
+	if (unveil(NULL, NULL) == -1)
+		err(1, "unveil");
+
 	if (rawmode && countmax == 0)
 		countmax = 1;
 
diff --git a/usr.bin/vmstat/vmstat.c b/usr.bin/vmstat/vmstat.c
index af88afcb006..742ce0022f1 100644
--- a/usr.bin/vmstat/vmstat.c
+++ b/usr.bin/vmstat/vmstat.c
@@ -1,5 +1,5 @@
 /*	$NetBSD: vmstat.c,v 1.29.4.1 1996/06/05 00:21:05 cgd Exp $	*/
-/*	$OpenBSD: vmstat.c,v 1.148 2019/10/14 14:40:00 deraadt Exp $	*/
+/*	$OpenBSD: vmstat.c,v 1.149 2019/10/14 19:22:17 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1980, 1986, 1991, 1993
@@ -131,6 +131,7 @@ main(int argc, char *argv[])
 {
 	char errbuf[_POSIX2_LINE_MAX];
 	int c, todo = 0, reps = 0;
+	struct winsize winsize;
 	const char *errstr;
 	u_int interval = 0;
 
@@ -207,16 +208,19 @@ main(int argc, char *argv[])
 	}
 
 	if (todo & VMSTAT) {
-		struct winsize winsize;
-
 		dkinit(0);	/* Initialize disk stats, no disks selected. */
 		argv = choosedrives(argv);	/* Select disks. */
-		winsize.ws_row = 0;
-		if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize) == 0) {
-			if (winsize.ws_row > 0)
-				winlines = winsize.ws_row;
-		}
+	}
+
+	if (unveil("/", "") == -1)
+		err(1, "unveil");
+	if (unveil(NULL, NULL) == -1)
+		err(1, "unveil");
 
+	winsize.ws_row = 0;
+	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize) == 0) {
+		if (winsize.ws_row > 0)
+			winlines = winsize.ws_row;
 	}
 
 #define	BACKWARD_COMPATIBILITY
diff --git a/usr.sbin/iostat/iostat.c b/usr.sbin/iostat/iostat.c
index 70a00fe5278..9384c3e47bc 100644
--- a/usr.sbin/iostat/iostat.c
+++ b/usr.sbin/iostat/iostat.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: iostat.c,v 1.41 2018/09/05 09:35:49 yasuoka Exp $	*/
+/*	$OpenBSD: iostat.c,v 1.42 2019/10/14 19:22:17 deraadt Exp $	*/
 /*	$NetBSD: iostat.c,v 1.10 1996/10/25 18:21:58 scottr Exp $	*/
 
 /*
@@ -161,6 +161,12 @@ main(int argc, char *argv[])
 		todo |= SHOW_CPU | SHOW_TTY | SHOW_STATS_1;
 
 	dkinit(0);
+
+	if (unveil("/", "") == -1)
+		err(1, "unveil");
+	if (unveil(NULL, NULL) == -1)
+		err(1, "unveil");
+
 	dkreadstats();
 	selectdrives(argv);