rndis_wlan: resize bssid list if too small

Buffer used for bssid list might be too small. Change rndis_query_oid()
to return required buffer length to caller and make rndis_check_bssid_list()
resize buffer when needed.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c
index 37796210db55..2309ad2214a0 100644
--- a/drivers/net/wireless/rndis_wlan.c
+++ b/drivers/net/wireless/rndis_wlan.c
@@ -676,7 +676,8 @@ static int rndis_query_oid(struct usbnet *dev, __le32 oid, void *data, int *len)
 
         if (ret == 0) {
                 ret = le32_to_cpu(u.get_c->len);
-                *len = (*len > ret) ? ret : *len;
+                if (ret > *len)
+                        *len = ret;
                 memcpy(data, u.buf + le32_to_cpu(u.get_c->offset) + 8, *len);
                 ret = rndis_error_status(u.get_c->status);
 
@@ -1656,6 +1657,9 @@ static struct cfg80211_bss *rndis_bss_info_update(struct usbnet *usbdev,
         int ie_len, bssid_len;
         u8 *ie;
 
+        devdbg(usbdev, " found bssid: '%.32s' [%pM]", bssid->ssid.essid,
+                                                        bssid->mac);
+
         /* parse bssid structure */
         bssid_len = le32_to_cpu(bssid->length);
 
@@ -1695,10 +1699,12 @@ static int rndis_check_bssid_list(struct usbnet *usbdev)
         struct ndis_80211_bssid_list_ex *bssid_list;
         struct ndis_80211_bssid_ex *bssid;
         int ret = -EINVAL, len, count, bssid_len;
+        bool resized = false;
 
         devdbg(usbdev, "check_bssid_list");
 
         len = CONTROL_BUFFER_SIZE;
+resize_buf:
         buf = kmalloc(len, GFP_KERNEL);
         if (!buf) {
                 ret = -ENOMEM;
@@ -1709,11 +1715,18 @@ static int rndis_check_bssid_list(struct usbnet *usbdev)
         if (ret != 0)
                 goto out;
 
+        if (!resized && len > CONTROL_BUFFER_SIZE) {
+                resized = true;
+                kfree(buf);
+                goto resize_buf;
+        }
+
         bssid_list = buf;
         bssid = bssid_list->bssid;
         bssid_len = le32_to_cpu(bssid->length);
         count = le32_to_cpu(bssid_list->num_items);
-        devdbg(usbdev, "check_bssid_list: %d BSSIDs found", count);
+        devdbg(usbdev, "check_bssid_list: %d BSSIDs found (buflen: %d)", count,
+                                                                        len);
 
         while (count && ((void *)bssid + bssid_len) <= (buf + len)) {
                 rndis_bss_info_update(usbdev, bssid);