staging: rtl8723au: Fix buffer overflow in rtw_get_wfd_ie()

Add bounds checking to not allow WFD Information Elements larger than
128, and make sure we use the correct buffer size MAX_WFD_IE_LEN
instea of hardcoding the size.

This also simplifies rtw_get_wfd_ie() by using the cfg80211
infrastructure.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rtl8723au/core/rtw_ieee80211.c b/drivers/staging/rtl8723au/core/rtw_ieee80211.c
index 780631fd3b6d4a8f9bbbb9b7662853f7ba5d9608..a48ab25a7d8a251cd93a30cb04349a09ce3cdf1b 100644 (file)
--- a/drivers/staging/rtl8723au/core/rtw_ieee80211.c
+++ b/drivers/staging/rtl8723au/core/rtw_ieee80211.c
@@ -1496,45 +1496,23 @@ void rtw_wlan_bssid_ex_remove_p2p_attr23a(struct wlan_bssid_ex *bss_ex, u8 attr_
 int rtw_get_wfd_ie(u8 *in_ie, int in_len, u8 *wfd_ie, uint *wfd_ielen)
 {
        int match;
-       uint cnt = 0;
-       u8 eid, wfd_oui[4] = {0x50, 0x6F, 0x9A, 0x0A};
+       const u8 *ie;
 
-       match = false;
+       match = 0;
 
-       if (in_len < 0) {
+       if (in_len < 0)
                return match;
-       }
-
-       while (cnt < in_len)
-       {
-               eid = in_ie[cnt];
 
-               if ((eid == _VENDOR_SPECIFIC_IE_) &&
-                   !memcmp(&in_ie[cnt+2], wfd_oui, 4)) {
-                       if (wfd_ie != NULL) {
-                               memcpy(wfd_ie, &in_ie[cnt], in_ie[cnt + 1] + 2);
-
-                       } else {
-                               if (wfd_ielen != NULL) {
-                                       *wfd_ielen = 0;
-                               }
-                       }
-
-                       if (wfd_ielen != NULL) {
-                               *wfd_ielen = in_ie[cnt + 1] + 2;
-                       }
-
-                       cnt += in_ie[cnt + 1] + 2;
-
-                       match = true;
-                       break;
-               } else {
-                       cnt += in_ie[cnt + 1] +2; /* goto next */
-               }
-       }
+       ie = cfg80211_find_vendor_ie(0x506F9A, 0x0A, in_ie, in_len);
+       if (ie && (ie[1] <= (MAX_WFD_IE_LEN - 2))) {
+               if (wfd_ie) {
+                       *wfd_ielen = ie[1] + 2;
+                       memcpy(wfd_ie, ie, ie[1] + 2);
+               } else
+                       if (wfd_ielen)
+                               *wfd_ielen = 0;
 
-       if (match == true) {
-               match = cnt;
+               match = 1;
        }
 
        return match;

diff --git a/drivers/staging/rtl8723au/core/rtw_mlme_ext.c b/drivers/staging/rtl8723au/core/rtw_mlme_ext.c
index 4c753639ea5a64b27ada4d02ea1d343bf16ada04..1f3e8a0aece4603a7b26a9b704290ef198f13caa 100644 (file)
--- a/drivers/staging/rtl8723au/core/rtw_mlme_ext.c
+++ b/drivers/staging/rtl8723au/core/rtw_mlme_ext.c
@@ -1281,7 +1281,7 @@ unsigned int OnAssocReq23a(struct rtw_adapter *padapter, struct recv_frame *prec
        u8 p2p_status_code = P2P_STATUS_SUCCESS;
        u8 *p2pie;
        u32 p2pielen = 0;
-       u8      wfd_ie[ 128 ] = { 0x00 };
+       u8      wfd_ie[MAX_WFD_IE_LEN] = { 0x00 };
        u32     wfd_ielen = 0;
 #endif /* CONFIG_8723AU_P2P */
 

diff --git a/drivers/staging/rtl8723au/core/rtw_p2p.c b/drivers/staging/rtl8723au/core/rtw_p2p.c
index 27a6cc76973de4970ba903d24060bab46f1a83d1..1a961e3f3a5541d183d6edeed532834d23e59892 100644 (file)
--- a/drivers/staging/rtl8723au/core/rtw_p2p.c
+++ b/drivers/staging/rtl8723au/core/rtw_p2p.c
@@ -2535,7 +2535,7 @@ u8 process_p2p_group_negotation_req23a(struct wifidirect_info *pwdinfo, u8 *pfra
        u16             wps_devicepassword_id = 0x0000;
        uint    wps_devicepassword_id_len = 0;
 #ifdef CONFIG_8723AU_P2P
-       u8      wfd_ie[ 128 ] = { 0x00 };
+       u8      wfd_ie[MAX_WFD_IE_LEN] = { 0x00 };
        u32     wfd_ielen = 0;
 #endif /*  CONFIG_8723AU_P2P */
 
@@ -2741,7 +2741,7 @@ u8 process_p2p_group_negotation_resp23a(struct wifidirect_info *pwdinfo, u8 *pfr
        u32 ies_len;
        u8 * p2p_ie;
 #ifdef CONFIG_8723AU_P2P
-       u8      wfd_ie[ 128 ] = { 0x00 };
+       u8      wfd_ie[MAX_WFD_IE_LEN] = { 0x00 };
        u32     wfd_ielen = 0;
 #endif /*  CONFIG_8723AU_P2P */
 

diff --git a/drivers/staging/rtl8723au/core/rtw_wlan_util.c b/drivers/staging/rtl8723au/core/rtw_wlan_util.c
index 0dfcfbce3b521f7fc241c3ead72136c0be75710d..e743b053b8a290c2b46dba567be9563e64f3117b 100644 (file)
--- a/drivers/staging/rtl8723au/core/rtw_wlan_util.c
+++ b/drivers/staging/rtl8723au/core/rtw_wlan_util.c
@@ -570,7 +570,7 @@ void flush_all_cam_entry23a(struct rtw_adapter *padapter)
 int WFD_info_handler(struct rtw_adapter *padapter, struct ndis_802_11_var_ies *        pIE)
 {
        struct wifidirect_info  *pwdinfo;
-       u8      wfd_ie[128] = {0x00};
+       u8      wfd_ie[MAX_WFD_IE_LEN] = {0x00};
        u32     wfd_ielen = 0;
 
        pwdinfo = &padapter->wdinfo;