staging: wfx: fix potential vulnerability to spectre

array_index_nospec() should be applied after a bound check.

Fixes: 9bca45f3d692 ("staging: wfx: allow to send 802.11 frames")
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20191011164746.2518-1-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/wfx/wfx.h b/drivers/staging/wfx/wfx.h
index 4898368..d678b5a 100644 (file)
--- a/drivers/staging/wfx/wfx.h
+++ b/drivers/staging/wfx/wfx.h
@@ -13,6 +13,7 @@
 #include <linux/completion.h>
 #include <linux/workqueue.h>
 #include <linux/mutex.h>
+#include <linux/nospec.h>
 #include <net/mac80211.h>
 
 #include "bh.h"
@@ -138,6 +139,7 @@ static inline struct wfx_vif *wdev_to_wvif(struct wfx_dev *wdev, int vif_id)
                dev_dbg(wdev->dev, "requesting non-existent vif: %d\n", vif_id);
                return NULL;
        }
+       vif_id = array_index_nospec(vif_id, ARRAY_SIZE(wdev->vif));
        if (!wdev->vif[vif_id]) {
                dev_dbg(wdev->dev, "requesting non-allocated vif: %d\n", vif_id);
                return NULL;