mac80211: fix SSID copy on IBSS JOIN

commit badecb001a310408d3473b1fc2ed5aefd0bc92a9 upstream.

The 'ssid' field of the cfg80211_ibss_params is a u8 pointer and
its length is likely to be less than IEEE80211_MAX_SSID_LEN most
of the time.

This patch fixes the ssid copy in ieee80211_ibss_join() by using
the SSID length to prevent it from reading beyond the string.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
[rewrapped commit message, small rewording]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 56c24cabf26d3cb6552f157320e1e782acff16cf..8adcc9e93b013cc6131957d0b322e2ed08fd22f3 100644 (file)
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -940,7 +940,7 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
        sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
        sdata->u.ibss.ibss_join_req = jiffies;
 
-       memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
+       memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
        sdata->u.ibss.ssid_len = params->ssid_len;
 
        mutex_unlock(&sdata->u.ibss.mtx);