ath6kl: check for sband existence when creating scan cmd

The patch "ath6kl: support fw reporting phy capabilities" gave the
firmware the ability to disable certain wiphy supported bands. Check if
this is the case in ath6kl_wmi_beginscan_cmd to avoid dereferencing a
NULL pointer.

kvalo: change the patch so that there's no code between declarations

Signed-off-by: Thomas Pedersen <c_tpeder@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
index bb802e49919c..102477d5900f 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.c
+++ b/drivers/net/wireless/ath/ath6kl/wmi.c
@@ -1818,12 +1818,14 @@ int ath6kl_wmi_beginscan_cmd(struct wmi *wmi, u8 if_idx,
                              u32 home_dwell_time, u32 force_scan_interval,
                              s8 num_chan, u16 *ch_list, u32 no_cck, u32 *rates)
 {
+        struct ieee80211_supported_band *sband;
         struct sk_buff *skb;
         struct wmi_begin_scan_cmd *sc;
-        s8 size;
+        s8 size, *supp_rates;
         int i, band, ret;
         struct ath6kl *ar = wmi->parent_dev;
         int num_rates;
+        u32 ratemask;
 
         size = sizeof(struct wmi_begin_scan_cmd);
 
@@ -1850,10 +1852,13 @@ int ath6kl_wmi_beginscan_cmd(struct wmi *wmi, u8 if_idx,
         sc->num_ch = num_chan;
 
         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
-                struct ieee80211_supported_band *sband =
-                    ar->wiphy->bands[band];
-                u32 ratemask = rates[band];
-                u8 *supp_rates = sc->supp_rates[band].rates;
+                sband = ar->wiphy->bands[band];
+
+                if (!sband)
+                        continue;
+
+                ratemask = rates[band];
+                supp_rates = sc->supp_rates[band].rates;
                 num_rates = 0;
 
                 for (i = 0; i < sband->n_bitrates; i++) {