From: Ondřej Surý <ondrej@sury.org>
Date: Thu, 17 Sep 2020 12:37:24 +0000 (+0200)
Subject: Handle the errors from sysconf() call in isc_meminfo_totalphys()
X-Git-Tag: v9.17.6~48^2~1
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=79ca724d46918387fba6b2dc484d67390bcbbd56;p=thirdparty%2Fbind9.git

Handle the errors from sysconf() call in isc_meminfo_totalphys()

isc_meminfo_totalphys() would return invalid memory size when sysconf()
call would fail, because ((size_t)-1 * -1) is very large number.
---

diff --git a/lib/isc/unix/meminfo.c b/lib/isc/unix/meminfo.c
index 04b01ce177c..46cb7d68550 100644
--- a/lib/isc/unix/meminfo.c
+++ b/lib/isc/unix/meminfo.c
@@ -35,7 +35,14 @@ isc_meminfo_totalphys(void) {
 #endif /* if defined(CTL_HW) && (defined(HW_PHYSMEM64) || defined(HW_MEMSIZE)) \
 	* */
 #if defined(_SC_PHYS_PAGES) && defined(_SC_PAGESIZE)
-	return ((size_t)(sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGESIZE)));
+	long pages = sysconf(_SC_PHYS_PAGES);
+	long pagesize = sysconf(_SC_PAGESIZE);
+
+	if (pages == -1 || pagesize == -1) {
+		return (0);
+	}
+
+	return ((size_t)pages * pagesize);
 #endif /* if defined(_SC_PHYS_PAGES) && defined(_SC_PAGESIZE) */
 	return (0);
 }