[PATCH v2] staging/rtl8192e: Remove all strcpy() uses

[PATCH v2] staging/rtl8192e: Remove all strcpy() uses

[Len Baker]

strcpy() performs no bounds checking on the destination buffer. This
could result in linear overflows beyond the end of the buffer, leading
to all kinds of misbehaviors. The safe replacement is strscpy().

It is also dangerous a strcpy() followed by a strcat(). In this case,
refactor the code using scnprintf() and avoid this combination.

Signed-off-by: Len Baker <len.baker@gmx.com>
---
Changelog v1 -> v2
- Refactor the code to avoid the strcpy() + strcat() combination (Dan
  Carpenter)

 drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c |  2 +-
 drivers/staging/rtl8192e/rtllib_softmac.c      |  3 ++-
 drivers/staging/rtl8192e/rtllib_softmac_wx.c   | 18 +++++++-----------
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c b/drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c
index b626ac45db80..358b629d2cc6 100644
--- a/drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c
+++ b/drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c
@@ -2167,7 +2167,7 @@ rtl92e_init_variables(struct net_device  *dev)
 {
 	struct r8192_priv *priv = rtllib_priv(dev);

-	strcpy(priv->nick, "rtl8192E");
+	strscpy(priv->nick, "rtl8192E", sizeof(priv->nick));

 	priv->rtllib->softmac_features  = IEEE_SOFTMAC_SCAN |
 		IEEE_SOFTMAC_ASSOCIATE | IEEE_SOFTMAC_PROBERQ |
diff --git a/drivers/staging/rtl8192e/rtllib_softmac.c b/drivers/staging/rtl8192e/rtllib_softmac.c
index 25b3d3950a3c..d2726d01c757 100644
--- a/drivers/staging/rtl8192e/rtllib_softmac.c
+++ b/drivers/staging/rtl8192e/rtllib_softmac.c
@@ -2582,7 +2582,8 @@ static void rtllib_start_ibss_wq(void *data)
 	mutex_lock(&ieee->wx_mutex);

 	if (ieee->current_network.ssid_len == 0) {
-		strcpy(ieee->current_network.ssid, RTLLIB_DEFAULT_TX_ESSID);
+		strscpy(ieee->current_network.ssid, RTLLIB_DEFAULT_TX_ESSID,
+			sizeof(ieee->current_network.ssid));
 		ieee->current_network.ssid_len = strlen(RTLLIB_DEFAULT_TX_ESSID);
 		ieee->ssid_set = 1;
 	}
diff --git a/drivers/staging/rtl8192e/rtllib_softmac_wx.c b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
index f89799d43b1b..57a6d1130b6a 100644
--- a/drivers/staging/rtl8192e/rtllib_softmac_wx.c
+++ b/drivers/staging/rtl8192e/rtllib_softmac_wx.c
@@ -539,18 +539,14 @@ int rtllib_wx_set_rawtx(struct rtllib_device *ieee,
 }
 EXPORT_SYMBOL(rtllib_wx_set_rawtx);

-int rtllib_wx_get_name(struct rtllib_device *ieee,
-			     struct iw_request_info *info,
-			     union iwreq_data *wrqu, char *extra)
+int rtllib_wx_get_name(struct rtllib_device *ieee, struct iw_request_info *info,
+		       union iwreq_data *wrqu, char *extra)
 {
-	strcpy(wrqu->name, "802.11");
-
-	if (ieee->modulation & RTLLIB_CCK_MODULATION)
-		strcat(wrqu->name, "b");
-	if (ieee->modulation & RTLLIB_OFDM_MODULATION)
-		strcat(wrqu->name, "g");
-	if (ieee->mode & (IEEE_N_24G | IEEE_N_5G))
-		strcat(wrqu->name, "n");
+	const char *b = ieee->modulation & RTLLIB_CCK_MODULATION ? "b" : "";
+	const char *g = ieee->modulation & RTLLIB_OFDM_MODULATION ? "g" : "";
+	const char *n = ieee->mode & (IEEE_N_24G | IEEE_N_5G) ? "n" : "";
+
+	scnprintf(wrqu->name, sizeof(wrqu->name), "802.11%s%s%s", b, g, n);
 	return 0;
 }
 EXPORT_SYMBOL(rtllib_wx_get_name);
--
2.25.1