watchdog: lenovo_se10_wdt: Fix use-after-free and resource leak risk

Review by sashiko.dev highlighted potential use after free and resource
leak instances.

Set se10_pdev to null to prevent use after free

Remove DMI call back and instead directly call
se10_create_platform_device. Handle error cases appropriately

Link: https://sashiko.dev/#/patchset/20260428124954.1193450-1-mpearson-lenovo%40squebb.ca
Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://lore.kernel.org/r/20260504180159.999189-1-mpearson-lenovo@squebb.ca
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/watchdog/lenovo_se10_wdt.c b/drivers/watchdog/lenovo_se10_wdt.c
index 99ff01af41243cdd52e7986cd4aed2cb4a2331eb..503e220263f95aa110e0b8916cb042074489fbfd 100644 (file)
--- a/drivers/watchdog/lenovo_se10_wdt.c
+++ b/drivers/watchdog/lenovo_se10_wdt.c
@@ -224,7 +224,7 @@ static struct platform_driver se10_wdt_driver = {
        .probe  = se10_wdt_probe,
 };
 
-static int se10_create_platform_device(const struct dmi_system_id *id)
+static int se10_create_platform_device(void)
 {
        int err;
 
@@ -233,9 +233,10 @@ static int se10_create_platform_device(const struct dmi_system_id *id)
                return -ENOMEM;
 
        err = platform_device_add(se10_pdev);
-       if (err)
+       if (err) {
                platform_device_put(se10_pdev);
-
+               se10_pdev = NULL;
+       }
        return err;
 }
 
@@ -246,7 +247,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "12NH"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10",
@@ -254,7 +254,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "12NJ"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10",
@@ -262,7 +261,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "12NK"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10",
@@ -270,7 +268,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "12NL"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10",
@@ -278,7 +275,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "12NM"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10-G2",
@@ -286,7 +282,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "13LJ"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10-G2",
@@ -294,7 +289,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "13LK"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10-G2",
@@ -302,7 +296,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "13S1"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10-G2",
@@ -310,7 +303,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "13S2"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10-G2",
@@ -318,7 +310,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "13S3"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10-G2",
@@ -326,7 +317,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "13S4"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10-G2",
@@ -334,7 +324,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "13S5"),
                },
-               .callback = se10_create_platform_device,
        },
        {
                .ident = "LENOVO-SE10-G2",
@@ -342,7 +331,6 @@ static const struct dmi_system_id se10_dmi_table[] __initconst = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "13S6"),
                },
-               .callback = se10_create_platform_device,
        },
        {}
 };
@@ -350,10 +338,20 @@ MODULE_DEVICE_TABLE(dmi, se10_dmi_table);
 
 static int __init se10_wdt_init(void)
 {
+       int err;
+
        if (!dmi_check_system(se10_dmi_table))
                return -ENODEV;
 
-       return platform_driver_register(&se10_wdt_driver);
+       err = platform_driver_register(&se10_wdt_driver);
+       if (err)
+               return err;
+
+       err = se10_create_platform_device();
+       if (err)
+               platform_driver_unregister(&se10_wdt_driver);
+
+       return err;
 }
 
 static void __exit se10_wdt_exit(void)