From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 25 Feb 2019 03:35:40 +0000 (+0900)
Subject: udev/ethtool: fix error detection of ethtool_link_mode_bit_from_string()
X-Git-Tag: v242-rc1~252^2~5
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=84fb56d396b14fb778dbe51f02d247f0899a74ef;p=thirdparty%2Fsystemd.git

udev/ethtool: fix error detection of ethtool_link_mode_bit_from_string()
---

diff --git a/src/udev/net/ethtool-util.c b/src/udev/net/ethtool-util.c
index 6a0a42386be..55620926dc4 100644
--- a/src/udev/net/ethtool-util.c
+++ b/src/udev/net/ethtool-util.c
@@ -775,7 +775,9 @@ int config_parse_advertise(const char *unit,
                         break;
 
                 mode = ethtool_link_mode_bit_from_string(w);
-                if (mode < 0) {
+                /* We reuse the kernel provided enum which does not contain negative value. So, the cast
+                 * below is mandatory. Otherwise, the check below always passes and access an invalid address. */
+                if ((int) mode < 0) {
                         log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse advertise mode, ignoring: %s", w);
                         continue;
                 }