pstore/ram: Fix failure-path memory leak in ramoops_init

[mirror_ubuntu-bionic-kernel.git] / fs / pstore / ram.c

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 7125b398d312e71714d96d4ed51baeff2e149601..351d70fe518bc6b59dde2c3256d8d900650d58a4 100644 (file)
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -896,8 +896,22 @@ static struct platform_driver ramoops_driver = {
        },
 };
 
-static void ramoops_register_dummy(void)
+static inline void ramoops_unregister_dummy(void)
 {
+       platform_device_unregister(dummy);
+       dummy = NULL;
+
+       kfree(dummy_data);
+       dummy_data = NULL;
+}
+
+static void __init ramoops_register_dummy(void)
+{
+       /*
+        * Prepare a dummy platform data structure to carry the module
+        * parameters. If mem_size isn't set, then there are no module
+        * parameters, and we can skip this.
+        */
        if (!mem_size)
                return;
 
@@ -930,21 +944,28 @@ static void ramoops_register_dummy(void)
        if (IS_ERR(dummy)) {
                pr_info("could not create platform device: %ld\n",
                        PTR_ERR(dummy));
+               dummy = NULL;
+               ramoops_unregister_dummy();
        }
 }
 
 static int __init ramoops_init(void)
 {
+       int ret;
+
        ramoops_register_dummy();
-       return platform_driver_register(&ramoops_driver);
+       ret = platform_driver_register(&ramoops_driver);
+       if (ret != 0)
+               ramoops_unregister_dummy();
+
+       return ret;
 }
 postcore_initcall(ramoops_init);
 
 static void __exit ramoops_exit(void)
 {
        platform_driver_unregister(&ramoops_driver);
-       platform_device_unregister(dummy);
-       kfree(dummy_data);
+       ramoops_unregister_dummy();
 }
 module_exit(ramoops_exit);