[PATCH] ieee80211: Fix iwlist scan can only show about 20 APs

Limit the amount of output given to iwlist scan.

Signed-off-by: Hong Liu <hong.liu@intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/net/ieee80211/ieee80211_wx.c b/net/ieee80211/ieee80211_wx.c
index 23e1630f50b7..f87c6b89f845 100644
--- a/net/ieee80211/ieee80211_wx.c
+++ b/net/ieee80211/ieee80211_wx.c
@@ -232,15 +232,18 @@ static char *ipw2100_translate_scan(struct ieee80211_device *ieee,
         return start;
 }
 
+#define SCAN_ITEM_SIZE 128
+
 int ieee80211_wx_get_scan(struct ieee80211_device *ieee,
                           struct iw_request_info *info,
                           union iwreq_data *wrqu, char *extra)
 {
         struct ieee80211_network *network;
         unsigned long flags;
+        int err = 0;
 
         char *ev = extra;
-        char *stop = ev + IW_SCAN_MAX_DATA;
+        char *stop = ev + wrqu->data.length;
         int i = 0;
 
         IEEE80211_DEBUG_WX("Getting scan\n");
@@ -249,6 +252,11 @@ int ieee80211_wx_get_scan(struct ieee80211_device *ieee,
 
         list_for_each_entry(network, &ieee->network_list, list) {
                 i++;
+                if (stop - ev < SCAN_ITEM_SIZE) {
+                        err = -E2BIG;
+                        break;
+                }
+
                 if (ieee->scan_age == 0 ||
                     time_after(network->last_scanned + ieee->scan_age, jiffies))
                         ev = ipw2100_translate_scan(ieee, ev, stop, network);
@@ -270,7 +278,7 @@ int ieee80211_wx_get_scan(struct ieee80211_device *ieee,
 
         IEEE80211_DEBUG_WX("exit: %d networks returned.\n", i);
 
-        return 0;
+        return err;
 }
 
 int ieee80211_wx_set_encode(struct ieee80211_device *ieee,