asoc: mbhc: avoid null pointer derefrence

fix to avoid null pointer dereference by checking
for the structure to be non-null, in below functions
wcd9378_mbhc_post_ssr_init of wcd9378-mbhc and
interpolate_zdet_val, usbcss_sysfs_store of wcd939x-mbhc.

Change-Id: I37979f969786c5490e1964913ad61123a4e09006
Signed-off-by: Srinivas Marka <[email protected]>

asoc/codecs/wcd9378/wcd9378-mbhc.c

@@ -1036,8 +1036,7 @@ int wcd9378_mbhc_post_ssr_init(struct wcd9378_mbhc *mbhc,
 {
 	int ret = 0;
 	struct wcd_mbhc *wcd_mbhc = NULL;
-	struct wcd9378_priv *wcd9378 =
-			dev_get_drvdata(component->dev);
+	struct wcd9378_priv *wcd9378 = NULL;
 
 	if (!mbhc || !component)
 		return -EINVAL;
@@ -1048,6 +1047,12 @@ int wcd9378_mbhc_post_ssr_init(struct wcd9378_mbhc *mbhc,
 		return -EINVAL;
 	}
 
+	wcd9378 = dev_get_drvdata(component->dev);
+	if (wcd9378 == NULL) {
+		pr_err("%s: wcd9378 is NULL\n", __func__);
+		return -EINVAL;
+	}
+
 	/* Reset detection type to insertion after SSR recovery */
 	snd_soc_component_update_bits(component, WCD9378_ANA_MBHC_MECH,
 				0x20, 0x20);
@@ -1088,14 +1093,19 @@ int wcd9378_mbhc_init(struct wcd9378_mbhc **mbhc,
 	struct wcd_mbhc *wcd_mbhc = NULL;
 	int ret = 0;
 	struct wcd9378_pdata *pdata;
-	struct wcd9378_priv *wcd9378 =
-			dev_get_drvdata(component->dev);
+	struct wcd9378_priv *wcd9378 = NULL;
 
 	if (!component) {
 		pr_err("%s: component is NULL\n", __func__);
 		return -EINVAL;
 	}
 
+	wcd9378 = dev_get_drvdata(component->dev);
+	if (!wcd9378) {
+		pr_err("%s: wcd9378 is NULL\n", __func__);
+		return -EINVAL;
+	}
+
 	wcd9378_mbhc = devm_kzalloc(component->dev, sizeof(struct wcd9378_mbhc),
 				    GFP_KERNEL);
 	if (!wcd9378_mbhc)

asoc/codecs/wcd939x/wcd939x-mbhc.c

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
- * Copyright (c) 2022-2023, Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2022-2024, Qualcomm Innovation Center, Inc. All rights reserved.
  */
 #include <linux/module.h>
 #include <linux/init.h>
@@ -836,6 +836,9 @@ static void interpolate_zdet_val(uint32_t *z, s64 z_meas_bias_removed, s64 z_val
 {
 	s64 lb_to_z = 0, lb_to_ub = 0, z_to_ub = 0, lb_corr = 0, ub_corr = 0, z_interp = 0;
 
+	if (lb < 0)
+		return;
+
 	/* If lb is the table upper bound, no interpolation needed, just use the lb corr factor */
 	if ((lb + 1) >= ARRAY_SIZE(zdet_dnl_table)) {
 		z_interp = (s64) ((flag_se_diff) ? (zdet_dnl_table[lb].diff_corr_mohms) :
@@ -977,10 +980,16 @@ static ssize_t usbcss_sysfs_store(struct kobject *kobj, struct kobj_attribute *a
 	bool update_xtalk = false, update_linearizer = false;
 
 	usbc_attr = container_of(attr, struct usbcss_hs_attr, attr);
+	if (!usbc_attr)
+		return -EINVAL;
+
 	wcd939x = usbc_attr->priv;
-	pdata = dev_get_platdata(wcd939x->dev);
 
-	if (!wcd939x || !pdata)
+	if (!wcd939x)
+		return -EINVAL;
+
+	pdata = dev_get_platdata(wcd939x->dev);
+	if (!pdata)
 		return -EINVAL;
 
 	usbcss_hs = &pdata->usbcss_hs;