diff --git a/sound/soc/codecs/cs-amp-lib-test.c b/sound/soc/codecs/cs-amp-lib-test.c
index 45626f99a417..d96d46eb5372 100644
--- a/sound/soc/codecs/cs-amp-lib-test.c
+++ b/sound/soc/codecs/cs-amp-lib-test.c
@@ -12,6 +12,7 @@
 #include <linux/gpio/driver.h>
 #include <linux/list.h>
 #include <linux/module.h>
+#include <linux/overflow.h>
 #include <linux/platform_device.h>
 #include <linux/random.h>
 #include <sound/cs-amp-lib.h>
@@ -40,8 +41,7 @@ static void cs_amp_lib_test_init_dummy_cal_blob(struct kunit *test, int num_amps
 	unsigned int blob_size;
 	int i;
 
-	blob_size = offsetof(struct cirrus_amp_efi_data, data) +
-		    sizeof(struct cirrus_amp_cal_data) * num_amps;
+	blob_size = struct_size(priv->cal_blob, data, num_amps);
 
 	priv->cal_blob = kunit_kzalloc(test, blob_size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_NULL(test, priv->cal_blob);
diff --git a/sound/soc/codecs/cs-amp-lib.c b/sound/soc/codecs/cs-amp-lib.c
index c677868c5d5f..808e67c90f7c 100644
--- a/sound/soc/codecs/cs-amp-lib.c
+++ b/sound/soc/codecs/cs-amp-lib.c
@@ -11,6 +11,7 @@
 #include <linux/efi.h>
 #include <linux/firmware/cirrus/cs_dsp.h>
 #include <linux/module.h>
+#include <linux/overflow.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <sound/cs-amp-lib.h>
@@ -147,7 +148,7 @@ static struct cirrus_amp_efi_data *cs_amp_get_cal_efi_buffer(struct device *dev)
 	dev_dbg(dev, "Calibration: Size=%d, Amp Count=%d\n", efi_data->size, efi_data->count);
 
 	if ((efi_data->count > 128) ||
-	    offsetof(struct cirrus_amp_efi_data, data[efi_data->count]) > data_size) {
+	    struct_size(efi_data, data, efi_data->count) > data_size) {
 		dev_err(dev, "EFI cal variable truncated\n");
 		ret = -EOVERFLOW;
 		goto err;