//RE: [PATCH] fix memory leak in ramoops_init

From: Nixiaoming
Date: Mon Sep 17 2018 - 06:03:23 EST


I am very sorry, I sent the wrong email, please ignore the patch just now.

-----Original Message-----
From: Nixiaoming
Sent: Monday, September 17, 2018 5:16 PM
To: jack@xxxxxxx; amir73il@xxxxxxxxx
Cc: Nixiaoming <nixiaoming@xxxxxxxxxx>; linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: [PATCH] fix memory leak in ramoops_init

1, memory leak in ramoops_register_dummy.
dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
but no free when platform_device_register_data return fail

2, if kzalloc(sizeof(*dummy_data), GFP_KERNEL) return NULL,
but platform_driver_register(&ramoops_driver) return 0
kfree(NULL) in ramoops_exit
so, add return val for ramoops_register_dummy, and check it in ramoops_init

3, memory leak in ramoops_init.
miss platform_device_unregister(dummy) and kfree(dummy_data)
when platform_driver_register(&ramoops_driver) return fail

Signed-off-by: nixiaoming <nixiaoming@xxxxxxxxxx>
---
fs/pstore/ram.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index bd9812e..331b600 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -604,17 +604,17 @@ static struct platform_driver ramoops_driver = {
},
};

-static void ramoops_register_dummy(void)
+static int ramoops_register_dummy(void)
{
if (!mem_size)
- return;
+ return -EINVAL;

pr_info("using module parameters\n");

dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
if (!dummy_data) {
pr_info("could not allocate pdata\n");
- return;
+ return -ENOMEM;
}

dummy_data->mem_size = mem_size;
@@ -636,13 +636,25 @@ static void ramoops_register_dummy(void)
if (IS_ERR(dummy)) {
pr_info("could not create platform device: %ld\n",
PTR_ERR(dummy));
+ kfree(dummy_data);
+ return PTR_ERR(dummy);
}
+ return 0;
}

static int __init ramoops_init(void)
{
- ramoops_register_dummy();
- return platform_driver_register(&ramoops_driver);
+ int ret = ramoops_register_dummy();
+
+ if (ret != 0)
+ return ret;
+
+ ret = platform_driver_register(&ramoops_driver);
+ if (ret != 0) {
+ platform_device_unregister(dummy);
+ kfree(dummy_data);
+ }
+ return ret;
}
postcore_initcall(ramoops_init);

--
1.9.0