From 208c72f4fe44fe09577e7975ba0e7fa0278f3d03 Mon Sep 17 00:00:00 2001 From: Luciano Coelho Date: Thu, 19 May 2011 00:43:38 +0300 Subject: [PATCH] nl80211: fix check for valid SSID size in scan operations In both trigger_scan and sched_scan operations, we were checking for the SSID length before assigning the value correctly. Since the memory was just kzalloc'ed, the check was always failing and SSID with over 32 characters were allowed to go through. This was causing a buffer overflow when copying the actual SSID to the proper place. This bug has been there since 2.6.29-rc4. Cc: stable@kernel.org Signed-off-by: Luciano Coelho Signed-off-by: John W. Linville --- net/wireless/nl80211.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index ec83f413a7ed..88a565f130a5 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3406,12 +3406,12 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info) i = 0; if (info->attrs[NL80211_ATTR_SCAN_SSIDS]) { nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_SSIDS], tmp) { + request->ssids[i].ssid_len = nla_len(attr); if (request->ssids[i].ssid_len > IEEE80211_MAX_SSID_LEN) { err = -EINVAL; goto out_free; } memcpy(request->ssids[i].ssid, nla_data(attr), nla_len(attr)); - request->ssids[i].ssid_len = nla_len(attr); i++; } } @@ -3572,6 +3572,7 @@ static int nl80211_start_sched_scan(struct sk_buff *skb, if (info->attrs[NL80211_ATTR_SCAN_SSIDS]) { nla_for_each_nested(attr, info->attrs[NL80211_ATTR_SCAN_SSIDS], tmp) { + request->ssids[i].ssid_len = nla_len(attr); if (request->ssids[i].ssid_len > IEEE80211_MAX_SSID_LEN) { err = -EINVAL; @@ -3579,7 +3580,6 @@ static int nl80211_start_sched_scan(struct sk_buff *skb, } memcpy(request->ssids[i].ssid, nla_data(attr), nla_len(attr)); - request->ssids[i].ssid_len = nla_len(attr); i++; } } -- 2.20.1