Staging: vt6655: fix buffer overflow

"param->u.wpa_associate.wpa_ie_len" comes from the user. We should check it so that the copy_from_user() doesn't overflow the buffer. Also further down in the function, we assume that if "param->u.wpa_associate.wpa_ie_len" is set then "abyWPAIE[0]" is initialized. To make that work, I changed the test here to say that if "wpa_ie_len" is set then "wpa_ie" has to be a valid pointer or we return -EINVAL. Oddly, we only use the first element of the abyWPAIE[] array. So I suspect there may be some other issues in this function. Signed-off-by: Dan Carpenter <[email protected]> Cc: stable <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
hanmiltonxing · Sep 20, 2010 · dd173ab · dd173ab
1 parent 350aede
commit dd173ab
Showing 1 changed file with 8 additions and 3 deletions.
diff --git a/drivers/staging/vt6655/wpactl.c b/drivers/staging/vt6655/wpactl.c
@@ -766,9 +766,14 @@ static int wpa_set_associate(PSDevice pDevice,
     DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "wpa_ie_len = %d\n", param->u.wpa_associate.wpa_ie_len);
 
 
-	if (param->u.wpa_associate.wpa_ie &&
-	    copy_from_user(&abyWPAIE[0], param->u.wpa_associate.wpa_ie, param->u.wpa_associate.wpa_ie_len))
-	    return -EINVAL;
+	if (param->u.wpa_associate.wpa_ie_len) {
+		if (!param->u.wpa_associate.wpa_ie)
+			return -EINVAL;
+		if (param->u.wpa_associate.wpa_ie_len > sizeof(abyWPAIE))
+			return -EINVAL;
+		if (copy_from_user(&abyWPAIE[0], param->u.wpa_associate.wpa_ie, param->u.wpa_associate.wpa_ie_len))
+			return -EFAULT;
+	}
 
 	if (param->u.wpa_associate.mode == 1)
 	    pMgmt->eConfigMode = WMAC_CONFIG_IBSS_STA;