[PATCH] staging/rtl8192u/ieee80211: Fix buffer overflow in ieee80211_softmac_wx.c

From: Peter Huewe
Date: Wed Feb 13 2013 - 22:04:44 EST


Clang/scan-build complains about a possible buffer overflow in
ieee80211_wx_get_name:

.../staging/rtl8192u/ieee80211/ieee80211_softmac_wx.c:499:3:
warning: String copy function overflows destination buffer
strcat(wrqu->name," link..");

.../staging/rtl8192u/ieee80211/ieee80211_softmac_wx.c:497:3:
warning: String copy function overflows destination buffer
strcat(wrqu->name," linked");

The buffer wrqu->name is only IFNAMSIZ bytes big (currently 16),
so if we have a "802.11b/g/n linked" device we overrun the buffer by 3
bytes.

-> Use strlcopy / strlcat to populate the name.
This is done in a similar fashion in
staging/rtl8187se/ieee80211/ieee80211_softmac_wx.c

While at it cleaned some whitespace issues.

Signed-off-by: Peter Huewe <peterhuewe@xxxxxx>
---
.../rtl8192u/ieee80211/ieee80211_softmac_wx.c | 29 ++++++++++---------
1 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac_wx.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac_wx.c
index 45422db..60746b8 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac_wx.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac_wx.c
@@ -482,22 +482,23 @@ int ieee80211_wx_get_name(struct ieee80211_device *ieee,
struct iw_request_info *info,
union iwreq_data *wrqu, char *extra)
{
- strcpy(wrqu->name, "802.11");
- if(ieee->modulation & IEEE80211_CCK_MODULATION){
- strcat(wrqu->name, "b");
- if(ieee->modulation & IEEE80211_OFDM_MODULATION)
- strcat(wrqu->name, "/g");
- }else if(ieee->modulation & IEEE80211_OFDM_MODULATION)
- strcat(wrqu->name, "g");
- if (ieee->mode & (IEEE_N_24G | IEEE_N_5G))
- strcat(wrqu->name, "/n");
+ strlcpy(wrqu->name, "802.11", IFNAMSIZ);
+ if (ieee->modulation & IEEE80211_CCK_MODULATION) {
+ strlcat(wrqu->name, "b", IFNAMSIZ);
+ if (ieee->modulation & IEEE80211_OFDM_MODULATION)
+ strlcat(wrqu->name, "/g", IFNAMSIZ);
+ } else if (ieee->modulation & IEEE80211_OFDM_MODULATION) {
+ strlcat(wrqu->name, "g", IFNAMSIZ);
+ }

- if((ieee->state == IEEE80211_LINKED) ||
- (ieee->state == IEEE80211_LINKED_SCANNING))
- strcat(wrqu->name," linked");
- else if(ieee->state != IEEE80211_NOLINK)
- strcat(wrqu->name," link..");
+ if (ieee->mode & (IEEE_N_24G | IEEE_N_5G))
+ strlcat(wrqu->name, "/n", IFNAMSIZ);

+ if ((ieee->state == IEEE80211_LINKED) ||
+ (ieee->state == IEEE80211_LINKED_SCANNING))
+ strlcat(wrqu->name, " linked", IFNAMSIZ);
+ else if (ieee->state != IEEE80211_NOLINK)
+ strlcat(wrqu->name, " link..", IFNAMSIZ);

return 0;
}
--
1.7.8.6

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