ASoC: aw88395: use struct_size() and __counted_by() for aw_container

The firmware container allocations passed cont->size + sizeof(int) to
kzalloc(), which was wrong: the struct contains an int len followed by a
u8 data[] flexible array. It ended up being the same as the struct's
size is only the int member but still wrong.

Use the modern struct_size helper for this.

Add __counted_by for extra runtime analysis.

Assisted-by: Claude:Opus-4.7
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20260523011749.101555-1-rosenp@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: neheb

sound/soc/codecs/aw88081.c

@@ -1137,6 +1137,7 @@ static int aw88081_dev_init(struct aw88081 *aw88081, struct aw_container *aw_cfg
 static int aw88081_request_firmware_file(struct aw88081 *aw88081)
 {
 	const struct firmware *cont = NULL;
+	struct aw_container *aw_cfg;
 	int ret;
 
 	aw88081->aw_pa->fw_status = AW88081_DEV_FW_FAILED;
@@ -1148,13 +1149,16 @@ static int aw88081_request_firmware_file(struct aw88081 *aw88081)
 	dev_dbg(aw88081->aw_pa->dev, "loaded %s - size: %zu\n",
 			AW88081_ACF_FILE, cont ? cont->size : 0);
 
-	aw88081->aw_cfg = devm_kzalloc(aw88081->aw_pa->dev, cont->size + sizeof(int), GFP_KERNEL);
-	if (!aw88081->aw_cfg) {
+	aw_cfg = devm_kzalloc(aw88081->aw_pa->dev, struct_size(aw_cfg, data, cont->size), GFP_KERNEL);
+	if (!aw_cfg) {
 		release_firmware(cont);
 		return -ENOMEM;
 	}
-	aw88081->aw_cfg->len = (int)cont->size;
-	memcpy(aw88081->aw_cfg->data, cont->data, cont->size);
+	aw_cfg->len = (int)cont->size;
+	memcpy(aw_cfg->data, cont->data, cont->size);
+
+	aw88081->aw_cfg = aw_cfg;
+
 	release_firmware(cont);
 
 	ret = aw88395_dev_load_acf_check(aw88081->aw_pa, aw88081->aw_cfg);

sound/soc/codecs/aw88261.c

@@ -1094,6 +1094,7 @@ static int aw88261_dev_init(struct aw88261 *aw88261, struct aw_container *aw_cfg
 static int aw88261_request_firmware_file(struct aw88261 *aw88261)
 {
 	const struct firmware *cont = NULL;
+	struct aw_container *aw_cfg;
 	const char *fw_name;
 	int ret;
 
@@ -1111,15 +1112,17 @@ static int aw88261_request_firmware_file(struct aw88261 *aw88261)
 	dev_info(aw88261->aw_pa->dev, "loaded %s - size: %zu\n",
 			fw_name, cont ? cont->size : 0);
 
-	aw88261->aw_cfg = devm_kzalloc(aw88261->aw_pa->dev, cont->size + sizeof(int), GFP_KERNEL);
-	if (!aw88261->aw_cfg) {
+	aw_cfg = devm_kzalloc(aw88261->aw_pa->dev, struct_size(aw_cfg, data, cont->size), GFP_KERNEL);
+	if (!aw_cfg) {
 		release_firmware(cont);
 		return -ENOMEM;
 	}
-	aw88261->aw_cfg->len = (int)cont->size;
-	memcpy(aw88261->aw_cfg->data, cont->data, cont->size);
+	aw_cfg->len = (int)cont->size;
+	memcpy(aw_cfg->data, cont->data, cont->size);
 	release_firmware(cont);
 
+	aw88261->aw_cfg = aw_cfg;
+
 	ret = aw88395_dev_load_acf_check(aw88261->aw_pa, aw88261->aw_cfg);
 	if (ret) {
 		dev_err(aw88261->aw_pa->dev, "load [%s] failed !", fw_name);

sound/soc/codecs/aw88395/aw88395.c

@@ -462,6 +462,7 @@ static void aw88395_hw_reset(struct aw88395 *aw88395)
 static int aw88395_request_firmware_file(struct aw88395 *aw88395)
 {
 	const struct firmware *cont = NULL;
+	struct aw_container *aw_cfg;
 	int ret;
 
 	aw88395->aw_pa->fw_status = AW88395_DEV_FW_FAILED;
@@ -475,15 +476,17 @@ static int aw88395_request_firmware_file(struct aw88395 *aw88395)
 	dev_info(aw88395->aw_pa->dev, "loaded %s - size: %zu\n",
 			AW88395_ACF_FILE, cont ? cont->size : 0);
 
-	aw88395->aw_cfg = devm_kzalloc(aw88395->aw_pa->dev, cont->size + sizeof(int), GFP_KERNEL);
-	if (!aw88395->aw_cfg) {
+	aw_cfg = devm_kzalloc(aw88395->aw_pa->dev, struct_size(aw_cfg, data, cont->size), GFP_KERNEL);
+	if (!aw_cfg) {
 		release_firmware(cont);
 		return -ENOMEM;
 	}
-	aw88395->aw_cfg->len = (int)cont->size;
-	memcpy(aw88395->aw_cfg->data, cont->data, cont->size);
+	aw_cfg->len = (int)cont->size;
+	memcpy(aw_cfg->data, cont->data, cont->size);
 	release_firmware(cont);
 
+	aw88395->aw_cfg = aw_cfg;
+
 	ret = aw88395_dev_load_acf_check(aw88395->aw_pa, aw88395->aw_cfg);
 	if (ret < 0) {
 		dev_err(aw88395->aw_pa->dev, "Load [%s] failed ....!", AW88395_ACF_FILE);

sound/soc/codecs/aw88395/aw88395_device.h

@@ -152,7 +152,7 @@ struct aw_cali_desc {
 
 struct aw_container {
 	int len;
-	u8 data[];
+	u8 data[] __counted_by(len);
 };
 
 struct aw_device {