Module Name: src
Committed By: christos
Date: Wed Aug 26 23:08:29 UTC 2020
Modified Files:
src/usr.bin/fstat: fstat.c
Log Message:
Provide a helpful error message if we don't have privs to read kernel
addresses.
To generate a diff of this commit:
cvs rdiff -u -r1.113 -r1.114 src/usr.bin/fstat/fstat.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/fstat/fstat.c
diff -u src/usr.bin/fstat/fstat.c:1.113 src/usr.bin/fstat/fstat.c:1.114
--- src/usr.bin/fstat/fstat.c:1.113 Fri Sep 6 13:08:22 2019
+++ src/usr.bin/fstat/fstat.c Wed Aug 26 19:08:29 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: fstat.c,v 1.113 2019/09/06 17:08:22 christos Exp $ */
+/* $NetBSD: fstat.c,v 1.114 2020/08/26 23:08:29 christos Exp $ */
/*-
* Copyright (c) 1988, 1993
@@ -39,7 +39,7 @@ __COPYRIGHT("@(#) Copyright (c) 1988, 19
#if 0
static char sccsid[] = "@(#)fstat.c 8.3 (Berkeley) 5/2/95";
#else
-__RCSID("$NetBSD: fstat.c,v 1.113 2019/09/06 17:08:22 christos Exp $");
+__RCSID("$NetBSD: fstat.c,v 1.114 2020/08/26 23:08:29 christos Exp $");
#endif
#endif /* not lint */
@@ -181,6 +181,7 @@ static void vtrans(struct file *, struct
static void ftrans(fdfile_t *, int);
static void ptrans(struct file *, struct pipe *, int);
static void kdriver_init(void);
+static void check_privs(void);
int
main(int argc, char **argv)
@@ -244,6 +245,8 @@ main(int argc, char **argv)
usage();
}
+ check_privs();
+
kdriver_init();
if (*(argv += optind)) {
@@ -309,6 +312,23 @@ main(int argc, char **argv)
return 0;
}
+static void
+check_privs(void)
+{
+ int expaddr;
+ size_t expsize = sizeof(expaddr);
+ const char *expname = "kern.expose_address";
+
+ if (geteuid() == 0)
+ return;
+
+ if (sysctlbyname(expname, &expaddr, &expsize, NULL, 0) == -1)
+ err(EXIT_FAILURE, "Can't get sysctl `%s'", expname);
+ if (expaddr == 0)
+ errx(EXIT_FAILURE, "This program does not work without "
+ "sysctl `%s' being set", expname);
+}
+
static const char *Uname, *Comm;
pid_t Pid;
