[PATCH] nl80211: fix get_inact_sec returning -1

[Joel Cunningham]

From 0c74513a8cde8f9518bc9b9e2f6095ccc4bbdf09 Mon Sep 17 00:00:00 2001
From: Joel Cunningham <joel.cunningham at me.com>
Date: Thu, 10 Nov 2016 13:24:41 -0600
Subject: [PATCH] nl80211: fix get_inact_sec returning -1

This commit fixes the nl80211 driver call get_inact_sec to return -1
when sta inactivity time retrieval fails in i802_read_sta_data

This was intended to be handled by initalizing the inactive_msec member
to -1 but i802_read_sta_data() assumes the data parameter is
uninitialized and memsets the entire structure, neutralizing the attempt
to distinguish between no value (-1) and a time value of 0

This is fixed by now requiring i802_read_sta_data callers to initialize
the data structure first (allowing get_inact_sec to use -1). This is a
safe change because it does not change any driver API behavior and only
affects one other static function in driver_nl80211.c

Signed-off-by: Joel Cunningham <joel.cunningham at me.com>
---
 src/drivers/driver_nl80211.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 75c4271..20ead77 100644
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -5647,8 +5647,6 @@ static int i802_read_sta_data(struct i802_bss *bss,
 {
 	struct nl_msg *msg;
 
-	os_memset(data, 0, sizeof(*data));
-
 	if (!(msg = nl80211_bss_msg(bss, 0, NL80211_CMD_GET_STATION)) ||
 	    nla_put(msg, NL80211_ATTR_MAC, ETH_ALEN, addr)) {
 		nlmsg_free(msg);
@@ -5754,6 +5752,7 @@ static int i802_get_inact_sec(void *priv, const u8 *addr)
 	struct hostap_sta_driver_data data;
 	int ret;
 
+	os_memset(&data, 0, sizeof(data));
 	data.inactive_msec = (unsigned long) -1;
 	ret = i802_read_sta_data(priv, &data, addr);
 	if (ret == -ENOENT)
@@ -7756,6 +7755,7 @@ static int driver_nl80211_read_sta_data(void *priv,
 					const u8 *addr)
 {
 	struct i802_bss *bss = priv;
+	os_memset(data, 0, sizeof(*data));
 	return i802_read_sta_data(bss, data, addr);
 }
 
-- 
2.9.3