staging: wfx: standardize the error when vif does not exist

Smatch complains:

   drivers/staging/wfx/hif_rx.c:177 hif_scan_complete_indication() warn: potential NULL parameter dereference 'wvif'
   drivers/staging/wfx/data_tx.c:576 wfx_flush() warn: potential NULL parameter dereference 'wvif'

Indeed, if the vif id returned by the device does not exist anymore,
wdev_to_wvif() could return NULL.

In add, the error is not handled uniformly in the code, sometime a
WARN() is displayed but code continue, sometime a dev_warn() is
displayed, sometime it is just not tested, ...

This patch standardize that.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20201009171307.864608-4-Jerome.Pouiller@silabs.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/wfx/data_tx.c b/drivers/staging/wfx/data_tx.c
index b4d5dd3..8db0be0 100644 (file)
--- a/drivers/staging/wfx/data_tx.c
+++ b/drivers/staging/wfx/data_tx.c
@@ -431,7 +431,10 @@ static void wfx_skb_dtor(struct wfx_vif *wvif, struct sk_buff *skb)
                              sizeof(struct hif_req_tx) +
                              req->fc_offset;
 
-       WARN_ON(!wvif);
+       if (!wvif) {
+               pr_warn("%s: vif associated with the skb does not exist anymore\n", __func__);
+               return;
+       }
        wfx_tx_policy_put(wvif, req->retry_policy_index);
        skb_pull(skb, offset);
        ieee80211_tx_status_irqsafe(wvif->wdev->hw, skb);

diff --git a/drivers/staging/wfx/hif_rx.c b/drivers/staging/wfx/hif_rx.c
index d6dfab0..ca09467 100644 (file)
--- a/drivers/staging/wfx/hif_rx.c
+++ b/drivers/staging/wfx/hif_rx.c
@@ -110,9 +110,9 @@ static int hif_receive_indication(struct wfx_dev *wdev,
        const struct hif_ind_rx *body = buf;
 
        if (!wvif) {
-               dev_warn(wdev->dev, "ignore rx data for non-existent vif %d\n",
-                        hif->interface);
-               return 0;
+               dev_warn(wdev->dev, "%s: ignore rx data for non-existent vif %d\n",
+                        __func__, hif->interface);
+               return -EIO;
        }
        skb_pull(skb, sizeof(struct hif_msg) + sizeof(struct hif_ind_rx));
        wfx_rx_cb(wvif, body, skb);
@@ -128,8 +128,8 @@ static int hif_event_indication(struct wfx_dev *wdev,
        int type = le32_to_cpu(body->event_id);
 
        if (!wvif) {
-               dev_warn(wdev->dev, "received event for non-existent vif\n");
-               return 0;
+               dev_warn(wdev->dev, "%s: received event for non-existent vif\n", __func__);
+               return -EIO;
        }
 
        switch (type) {
@@ -161,7 +161,10 @@ static int hif_pm_mode_complete_indication(struct wfx_dev *wdev,
 {
        struct wfx_vif *wvif = wdev_to_wvif(wdev, hif->interface);
 
-       WARN_ON(!wvif);
+       if (!wvif) {
+               dev_warn(wdev->dev, "%s: received event for non-existent vif\n", __func__);
+               return -EIO;
+       }
        complete(&wvif->set_pm_mode_complete);
 
        return 0;
@@ -173,7 +176,11 @@ static int hif_scan_complete_indication(struct wfx_dev *wdev,
 {
        struct wfx_vif *wvif = wdev_to_wvif(wdev, hif->interface);
 
-       WARN_ON(!wvif);
+       if (!wvif) {
+               dev_warn(wdev->dev, "%s: received event for non-existent vif\n", __func__);
+               return -EIO;
+       }
+
        wfx_scan_complete(wvif);
 
        return 0;
@@ -185,7 +192,10 @@ static int hif_join_complete_indication(struct wfx_dev *wdev,
 {
        struct wfx_vif *wvif = wdev_to_wvif(wdev, hif->interface);
 
-       WARN_ON(!wvif);
+       if (!wvif) {
+               dev_warn(wdev->dev, "%s: received event for non-existent vif\n", __func__);
+               return -EIO;
+       }
        dev_warn(wdev->dev, "unattended JoinCompleteInd\n");
 
        return 0;
@@ -195,11 +205,15 @@ static int hif_suspend_resume_indication(struct wfx_dev *wdev,
                                         const struct hif_msg *hif,
                                         const void *buf)
 {
-       struct wfx_vif *wvif = wdev_to_wvif(wdev, hif->interface);
        const struct hif_ind_suspend_resume_tx *body = buf;
+       struct wfx_vif *wvif;
 
        if (body->bc_mc_only) {
-               WARN_ON(!wvif);
+               wvif = wdev_to_wvif(wdev, hif->interface);
+               if (!wvif) {
+                       dev_warn(wdev->dev, "%s: received event for non-existent vif\n", __func__);
+                       return -EIO;
+               }
                if (body->resume)
                        wfx_suspend_resume_mc(wvif, STA_NOTIFY_AWAKE);
                else

diff --git a/drivers/staging/wfx/sta.c b/drivers/staging/wfx/sta.c
index a246f0d..2320a81 100644 (file)
--- a/drivers/staging/wfx/sta.c
+++ b/drivers/staging/wfx/sta.c
@@ -619,6 +619,10 @@ int wfx_set_tim(struct ieee80211_hw *hw, struct ieee80211_sta *sta, bool set)
        struct wfx_sta_priv *sta_dev = (struct wfx_sta_priv *)&sta->drv_priv;
        struct wfx_vif *wvif = wdev_to_wvif(wdev, sta_dev->vif_id);
 
+       if (!wvif) {
+               dev_warn(wdev->dev, "%s: received event for non-existent vif\n", __func__);
+               return -EIO;
+       }
        schedule_work(&wvif->update_tim_work);
        return 0;
 }