From dan@aloni.org Fri Jul 10 11:03:29 2009 From: Dan Aloni Date: Sat, 20 Jun 2009 16:32:22 +0300 Subject: Staging: prevent rtl8187se from crashing dev_ioctl() in SIOCGIWNAME Cc: Greg Kroah-Hartman Message-ID: <20090620133222.GA18731@localhost> I repeatedly get __stack_chk_fail panic()s with this driver before applying the attached fix. ieee80211_wx_get_name() ignores sizeof(wrqu->name) which is IFNAMSIZ (16), and on certain conditions, the concatenated string will be larger than IFNAMSIZ including the terminating zero. length ("802.11" ++ "b" ++ "/g" ++ " linked" ++ "\x00") == 17 This fix uses strl{cpy,cat} in addition to the reduction of the total possible length of the output string by a char. It can be applied to 2.6.30-stable as well. Signed-off-by: Dan Aloni Cc: Bartlomiej Zolnierkiewicz Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rtl8187se/ieee80211/ieee80211_softmac_wx.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/drivers/staging/rtl8187se/ieee80211/ieee80211_softmac_wx.c +++ b/drivers/staging/rtl8187se/ieee80211/ieee80211_softmac_wx.c @@ -461,19 +461,19 @@ int ieee80211_wx_get_name(struct ieee802 struct iw_request_info *info, union iwreq_data *wrqu, char *extra) { - strcpy(wrqu->name, "802.11"); + strlcpy(wrqu->name, "802.11", IFNAMSIZ); if(ieee->modulation & IEEE80211_CCK_MODULATION){ - strcat(wrqu->name, "b"); + strlcat(wrqu->name, "b", IFNAMSIZ); if(ieee->modulation & IEEE80211_OFDM_MODULATION) - strcat(wrqu->name, "/g"); + strlcat(wrqu->name, "/g", IFNAMSIZ); }else if(ieee->modulation & IEEE80211_OFDM_MODULATION) - strcat(wrqu->name, "g"); + strlcat(wrqu->name, "g", IFNAMSIZ); if((ieee->state == IEEE80211_LINKED) || (ieee->state == IEEE80211_LINKED_SCANNING)) - strcat(wrqu->name," linked"); + strlcat(wrqu->name," link", IFNAMSIZ); else if(ieee->state != IEEE80211_NOLINK) - strcat(wrqu->name," link.."); + strlcat(wrqu->name," .....", IFNAMSIZ); return 0;