devm_kasprintf() in ap_cp_unique_name() returns NULL when memory
allocation fails. Currently, ap806_syscon_common_probe() does not check
for this case, which results in a NULL pointer dereference.

Add NULL check after ap_cp_unique_name() to prevent this issue.

Fixes: baf4c10f8878 ("clk: mvebu: ap806: Fix clock name for the cluster")
Fixes: 33c0259092c8 ("clk: mvebu: add helper file for Armada AP and CP clocks")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
---
 drivers/clk/mvebu/ap806-system-controller.c | 24 +++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/clk/mvebu/ap806-system-controller.c b/drivers/clk/mvebu/ap806-system-controller.c
index 948bd1e71aea..1461922752e3 100644
--- a/drivers/clk/mvebu/ap806-system-controller.c
+++ b/drivers/clk/mvebu/ap806-system-controller.c
@@ -173,6 +173,10 @@ static int ap806_syscon_common_probe(struct platform_device *pdev,
 
 	/* CPU clocks depend on the Sample At Reset configuration */
 	name = ap_cp_unique_name(dev, syscon_node, "pll-cluster-0");
+	if (!name) {
+		ret = -ENOMEM;
+		goto fail0;
+	}
 	ap806_clks[0] = clk_register_fixed_rate(dev, name, NULL,
 						0, cpuclk_freq);
 	if (IS_ERR(ap806_clks[0])) {
@@ -181,6 +185,10 @@ static int ap806_syscon_common_probe(struct platform_device *pdev,
 	}
 
 	name = ap_cp_unique_name(dev, syscon_node, "pll-cluster-1");
+	if (!name) {
+		ret = -ENOMEM;
+		goto fail1;
+	}
 	ap806_clks[1] = clk_register_fixed_rate(dev, name, NULL, 0,
 						cpuclk_freq);
 	if (IS_ERR(ap806_clks[1])) {
@@ -190,6 +198,10 @@ static int ap806_syscon_common_probe(struct platform_device *pdev,
 
 	/* Fixed clock is always 1200 Mhz */
 	fixedclk_name = ap_cp_unique_name(dev, syscon_node, "fixed");
+	if (!name) {
+		ret = -ENOMEM;
+		goto fail2;
+	}
 	ap806_clks[2] = clk_register_fixed_rate(dev, fixedclk_name, NULL,
 						0, 1200 * 1000 * 1000);
 	if (IS_ERR(ap806_clks[2])) {
@@ -199,6 +211,10 @@ static int ap806_syscon_common_probe(struct platform_device *pdev,
 
 	/* MSS Clock is fixed clock divided by 6 */
 	name = ap_cp_unique_name(dev, syscon_node, "mss");
+	if (!name) {
+		ret = -ENOMEM;
+		goto fail3;
+	}
 	ap806_clks[3] = clk_register_fixed_factor(NULL, name, fixedclk_name,
 						  0, 1, 6);
 	if (IS_ERR(ap806_clks[3])) {
@@ -208,6 +224,10 @@ static int ap806_syscon_common_probe(struct platform_device *pdev,
 
 	/* SDIO(/eMMC) Clock is fixed clock divided by 3 */
 	name = ap_cp_unique_name(dev, syscon_node, "sdio");
+	if (!name) {
+		ret = -ENOMEM;
+		goto fail4;
+	}
 	ap806_clks[4] = clk_register_fixed_factor(NULL, name,
 						  fixedclk_name,
 						  0, 1, 3);
@@ -218,6 +238,10 @@ static int ap806_syscon_common_probe(struct platform_device *pdev,
 
 	/* AP-DCLK(HCLK) Clock is DDR clock divided by 2 */
 	name = ap_cp_unique_name(dev, syscon_node, "ap-dclk");
+	if (!name) {
+		ret = -ENOMEM;
+		goto fail5;
+	}
 	ap806_clks[5] = clk_register_fixed_rate(dev, name, NULL, 0, dclk_freq);
 	if (IS_ERR(ap806_clks[5])) {
 		ret = PTR_ERR(ap806_clks[5]);
-- 
2.34.1

Quoting Henry Martin (2025-04-09 20:04:38)
> devm_kasprintf() in ap_cp_unique_name() returns NULL when memory
> allocation fails. Currently, ap806_syscon_common_probe() does not check
> for this case, which results in a NULL pointer dereference.
> 
> Add NULL check after ap_cp_unique_name() to prevent this issue.
> 
> Fixes: baf4c10f8878 ("clk: mvebu: ap806: Fix clock name for the cluster")
> Fixes: 33c0259092c8 ("clk: mvebu: add helper file for Armada AP and CP clocks")
> Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
> ---
>  drivers/clk/mvebu/ap806-system-controller.c | 24 +++++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 
> diff --git a/drivers/clk/mvebu/ap806-system-controller.c b/drivers/clk/mvebu/ap806-system-controller.c
> index 948bd1e71aea..1461922752e3 100644
> --- a/drivers/clk/mvebu/ap806-system-controller.c
> +++ b/drivers/clk/mvebu/ap806-system-controller.c
> @@ -173,6 +173,10 @@ static int ap806_syscon_common_probe(struct platform_device *pdev,
>  
>         /* CPU clocks depend on the Sample At Reset configuration */
>         name = ap_cp_unique_name(dev, syscon_node, "pll-cluster-0");
> +       if (!name) {
> +               ret = -ENOMEM;
> +               goto fail0;
> +       }
>         ap806_clks[0] = clk_register_fixed_rate(dev, name, NULL,

TL;DR: This patch is unnecessary.

If name is NULL this function will fail. See the kstrdup_const() call in
__clk_register() and how it returns -ENOMEM when the copy of the
init.name is NULL, which is what happens when you duplicate a NULL
pointer.