[PATCH v3] staging: wfx: fix potential vulnerability to spectre

[Jerome Pouiller]

From: JÃrÃme Pouiller <jerome.pouiller@xxxxxxxxxx>

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@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: JÃrÃme Pouiller <jerome.pouiller@xxxxxxxxxx>
---
v2: cut down commit-id to 12 characters
v3: fix missing include

 drivers/staging/wfx/wfx.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/wfx/wfx.h b/drivers/staging/wfx/wfx.h
index 489836837b0a..d678b5a08873 100644
--- 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;
-- 
2.20.1