qcacld-3.0: Fix NULL pointer dereference issue in DP

Pointer 'dp_ctx' returned from call to function 'dp_psoc_get_priv'
may be NULL in below APIs:
ucfg_dp_set_hif_handle
ucfg_dp_update_config
ucfg_dp_get_rx_softirq_yield_duration
ucfg_dp_register_rx_mic_error_ind_handler
ucfg_dp_is_roam_after_nud_enabled

Fix is to add NULL check for dp_ctx before use.

Change-Id: I040f1a6ed92ad572e625663eee9ea1dd0c5e8530
CRs-Fixed: 3770367

components/dp/dispatcher/src/wlan_dp_ucfg_api.c

@@ -319,6 +319,10 @@ void ucfg_dp_set_hif_handle(struct wlan_objmgr_psoc *psoc,
 	struct wlan_dp_psoc_context *dp_ctx;
 
 	dp_ctx = dp_psoc_get_priv(psoc);
+	if (!dp_ctx) {
+		dp_err("Unable to get DP context");
+		return;
+	}
 
 	dp_ctx->hif_handle = hif_handle;
 }
@@ -1057,6 +1061,10 @@ ucfg_dp_update_config(struct wlan_objmgr_psoc *psoc,
 	void *soc;
 
 	dp_ctx =  dp_psoc_get_priv(psoc);
+	if (!dp_ctx) {
+		dp_err("Unable to get DP context");
+		return QDF_STATUS_E_INVAL;
+	}
 
 	dp_ctx->arp_connectivity_map = req->arp_connectivity_map;
 	soc = cds_get_context(QDF_MODULE_ID_SOC);
@@ -1097,7 +1105,13 @@ ucfg_dp_update_config(struct wlan_objmgr_psoc *psoc,
 uint64_t
 ucfg_dp_get_rx_softirq_yield_duration(struct wlan_objmgr_psoc *psoc)
 {
-	struct wlan_dp_psoc_context *dp_ctx = dp_psoc_get_priv(psoc);
+	struct wlan_dp_psoc_context *dp_ctx;
+
+	dp_ctx = dp_psoc_get_priv(psoc);
+	if (!dp_ctx) {
+		dp_err("Unable to get DP context");
+		return 0;
+	}
 
 	return dp_ctx->dp_cfg.rx_softirq_max_yield_duration_ns;
 }
@@ -1537,8 +1551,20 @@ void ucfg_dp_register_rx_mic_error_ind_handler(void *soc)
 bool
 ucfg_dp_is_roam_after_nud_enabled(struct wlan_objmgr_psoc *psoc)
 {
-	struct wlan_dp_psoc_context *dp_ctx = dp_psoc_get_priv(psoc);
-	struct wlan_dp_psoc_cfg *dp_cfg = &dp_ctx->dp_cfg;
+	struct wlan_dp_psoc_context *dp_ctx;
+	struct wlan_dp_psoc_cfg *dp_cfg;
+
+	dp_ctx = dp_psoc_get_priv(psoc);
+	if (!dp_ctx) {
+		dp_err("Unable to get DP context");
+		return false;
+	}
+
+	dp_cfg = &dp_ctx->dp_cfg;
+	if (!dp_cfg) {
+		dp_err("Unable to get DP config");
+		return false;
+	}
 
 	if (dp_cfg->enable_nud_tracking == DP_ROAM_AFTER_NUD_FAIL ||
 	    dp_cfg->enable_nud_tracking == DP_DISCONNECT_AFTER_ROAM_FAIL)
@@ -1550,8 +1576,20 @@ ucfg_dp_is_roam_after_nud_enabled(struct wlan_objmgr_psoc *psoc)
 bool
 ucfg_dp_is_disconect_after_roam_fail(struct wlan_objmgr_psoc *psoc)
 {
-	struct wlan_dp_psoc_context *dp_ctx = dp_psoc_get_priv(psoc);
-	struct wlan_dp_psoc_cfg *dp_cfg = &dp_ctx->dp_cfg;
+	struct wlan_dp_psoc_context *dp_ctx;
+	struct wlan_dp_psoc_cfg *dp_cfg;
+
+	dp_ctx = dp_psoc_get_priv(psoc);
+	if (!dp_ctx) {
+		dp_err("Unable to get DP context");
+		return false;
+	}
+
+	dp_cfg = &dp_ctx->dp_cfg;
+	if (!dp_cfg) {
+		dp_err("Unable to get DP config");
+		return false;
+	}
 
 	if (dp_cfg->enable_nud_tracking == DP_DISCONNECT_AFTER_ROAM_FAIL)
 		return true;