diff mbox series

[v3] i2c: fix memleak in i2c_new_client_device()

Message ID 20230929091952.19957-1-wsa+renesas@sang-engineering.com
State New
Headers
Series [v3] i2c: fix memleak in i2c_new_client_device() |

Commit Message

Wolfram Sang Sept. 29, 2023, 9:19 a.m. UTC 
  Yang Yingliang reported a memleak:
===

I got memory leak as follows when doing fault injection test:

unreferenced object 0xffff888014aec078 (size 8):
  comm "xrun", pid 356, jiffies 4294910619 (age 16.332s)
  hex dump (first 8 bytes):
    31 2d 30 30 31 63 00 00                          1-001c..
  backtrace:
    [<00000000eb56c0a9>] __kmalloc_track_caller+0x1a6/0x300
    [<000000000b220ea3>] kvasprintf+0xad/0x140
    [<00000000b83203e5>] kvasprintf_const+0x62/0x190
    [<000000002a5eab37>] kobject_set_name_vargs+0x56/0x140
    [<00000000300ac279>] dev_set_name+0xb0/0xe0
    [<00000000b66ebd6f>] i2c_new_client_device+0x7e4/0x9a0

If device_register() returns error in i2c_new_client_device(),
the name allocated by i2c_dev_set_name() need be freed. As
comment of device_register() says, it should use put_device()
to give up the reference in the error path.

===
I think this solution is less intrusive and more robust than he
originally proposed solutions, though.

Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Closes: http://patchwork.ozlabs.org/project/linux-i2c/patch/20221124085448.3620240-1-yangyingliang@huawei.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Build tested only.

@Yang Yingliang: I'd be happy if you could test it/comment on it.

 drivers/i2c/i2c-core-base.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

Comments

Wolfram Sang Oct. 23, 2023, 3:26 p.m. UTC | #1 
On Fri, Sep 29, 2023 at 11:19:52AM +0200, Wolfram Sang wrote:
> Yang Yingliang reported a memleak:
> ===
> 
> I got memory leak as follows when doing fault injection test:
> 
> unreferenced object 0xffff888014aec078 (size 8):
>   comm "xrun", pid 356, jiffies 4294910619 (age 16.332s)
>   hex dump (first 8 bytes):
>     31 2d 30 30 31 63 00 00                          1-001c..
>   backtrace:
>     [<00000000eb56c0a9>] __kmalloc_track_caller+0x1a6/0x300
>     [<000000000b220ea3>] kvasprintf+0xad/0x140
>     [<00000000b83203e5>] kvasprintf_const+0x62/0x190
>     [<000000002a5eab37>] kobject_set_name_vargs+0x56/0x140
>     [<00000000300ac279>] dev_set_name+0xb0/0xe0
>     [<00000000b66ebd6f>] i2c_new_client_device+0x7e4/0x9a0
> 
> If device_register() returns error in i2c_new_client_device(),
> the name allocated by i2c_dev_set_name() need be freed. As
> comment of device_register() says, it should use put_device()
> to give up the reference in the error path.
> 
> ===
> I think this solution is less intrusive and more robust than he
> originally proposed solutions, though.
> 
> Reported-by: Yang Yingliang <yangyingliang@huawei.com>
> Closes: http://patchwork.ozlabs.org/project/linux-i2c/patch/20221124085448.3620240-1-yangyingliang@huawei.com/
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Applied to for-next, thanks!
diff mbox series

Patch

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index cc4a20465456..0d6172d6b808 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -931,8 +931,9 @@  int i2c_dev_irq_from_resources(const struct resource *resources,
 struct i2c_client *
 i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
 {
-	struct i2c_client	*client;
-	int			status;
+	struct i2c_client *client;
+	bool need_put = false;
+	int status;
 
 	client = kzalloc(sizeof *client, GFP_KERNEL);
 	if (!client)
@@ -970,7 +971,6 @@  i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
 	client->dev.fwnode = info->fwnode;
 
 	device_enable_async_suspend(&client->dev);
-	i2c_dev_set_name(adap, client, info);
 
 	if (info->swnode) {
 		status = device_add_software_node(&client->dev, info->swnode);
@@ -982,6 +982,7 @@  i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
 		}
 	}
 
+	i2c_dev_set_name(adap, client, info);
 	status = device_register(&client->dev);
 	if (status)
 		goto out_remove_swnode;
@@ -993,6 +994,7 @@  i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
 
 out_remove_swnode:
 	device_remove_software_node(&client->dev);
+	need_put = true;
 out_err_put_of_node:
 	of_node_put(info->of_node);
 out_err:
@@ -1000,7 +1002,10 @@  i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
 		"Failed to register i2c client %s at 0x%02x (%d)\n",
 		client->name, client->addr, status);
 out_err_silent:
-	kfree(client);
+	if (need_put)
+		put_device(&client->dev);
+	else
+		kfree(client);
 	return ERR_PTR(status);
 }
 EXPORT_SYMBOL_GPL(i2c_new_client_device);