staging: rtl8723bs: fix OOB reads in is_ap_in_tkip() IE loop

The loop in is_ap_in_tkip() iterates over IEs without verifying that
enough bytes remain before dereferencing the IE header or its payload:

- pIE->element_id and pIE->length are read without checking that
  i + sizeof(*pIE) <= ie_length, so a truncated IE at the end of the
  buffer causes an OOB read.

- For WLAN_EID_VENDOR_SPECIFIC the code compares pIE->data + 12,
  which requires pIE->length >= 16.  For WLAN_EID_RSN it compares
  pIE->data + 8, requiring pIE->length >= 12.  Neither requirement
  is checked.

Add the missing IE header and payload bounds checks and guard each
data access with an explicit pIE->length minimum, matching the
pattern established in update_beacon_info().

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Alexandru Hossu <hossu.alexandru@gmail.com>
Link: https://patch.msgid.link/20260522004531.1038924-7-hossu.alexandru@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c
index 4c0eb93f412e4fdd823fa2eee82fbc2ba709ae7e..a4de538722b56e5ee13e7a2bb3506342b4dd8b4c 100644 (file)
--- a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c
+++ b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c
@@ -1308,15 +1308,23 @@ unsigned int is_ap_in_tkip(struct adapter *padapter)
                for (i = sizeof(struct ndis_802_11_fix_ie); i < pmlmeinfo->network.ie_length;) {
                        pIE = (struct ndis_80211_var_ie *)(pmlmeinfo->network.ies + i);
 
+                       if (i + sizeof(*pIE) > pmlmeinfo->network.ie_length)
+                               break;
+                       if (i + sizeof(*pIE) + pIE->length > pmlmeinfo->network.ie_length)
+                               break;
+
                        switch (pIE->element_id) {
                        case WLAN_EID_VENDOR_SPECIFIC:
-                               if ((!memcmp(pIE->data, RTW_WPA_OUI, 4)) && (!memcmp((pIE->data + 12), WPA_TKIP_CIPHER, 4)))
+                               if (pIE->length >= 16 &&
+                                   !memcmp(pIE->data, RTW_WPA_OUI, 4) &&
+                                   !memcmp((pIE->data + 12), WPA_TKIP_CIPHER, 4))
                                        return true;
 
                                break;
 
                        case WLAN_EID_RSN:
-                               if (!memcmp((pIE->data + 8), RSN_TKIP_CIPHER, 4))
+                               if (pIE->length >= 12 &&
+                                   !memcmp((pIE->data + 8), RSN_TKIP_CIPHER, 4))
                                        return true;
                                break;
 
@@ -1324,7 +1332,7 @@ unsigned int is_ap_in_tkip(struct adapter *padapter)
                                break;
                        }
 
-                       i += (pIE->length + 2);
+                       i += sizeof(*pIE) + pIE->length;
                }
 
                return false;