Commit b8c3511d authored May 14, 2019 by Markus Armbruster

qemu-bridge-helper: Fix misuse of isspace()



parse_acl_file() passes char values to isspace().  Undefined behavior
when the value is negative.  Not a security issue, because the
characters come from trusted $prefix/etc/qemu/bridge.conf and the
files it includes.

Furthermore, isspace()'s locale-dependence means qemu-bridge-helper
uses the user's locale for parsing $prefix/etc/bridge.conf.  Feels
wrong.

Use g_ascii_isspace() instead.  This fixes the undefined behavior, and
makes parsing of $prefix/etc/bridge.conf locale-independent.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190514180311.16028-2-armbru@redhat.com>

parent a4f667b6

qemu-bridge-helper.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -75,7 +75,7 @@ static int parse_acl_file(const char filename, ACLList acl_list)
		char *ptr = line;
		char cmd, arg, *argend;

		while (isspace(*ptr)) {
		while (g_ascii_isspace(*ptr)) {
		ptr++;
		}

		@@ -99,12 +99,12 @@ static int parse_acl_file(const char filename, ACLList acl_list)

		*arg = 0;
		arg++;
		while (isspace(*arg)) {
		while (g_ascii_isspace(*arg)) {
		arg++;
		}

		argend = arg + strlen(arg);
		while (arg != argend && isspace(*(argend - 1))) {
		while (arg != argend && g_ascii_isspace(*(argend - 1))) {
		argend--;
		}
		*argend = 0;