Commit 6af79f7f authored by Wolfram Sang's avatar Wolfram Sang Committed by Wolfram Sang
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i2c: fix memleak in i2c_new_client_device() 



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: default avatarYang Yingliang <yangyingliang@huawei.com>
Closes: http://patchwork.ozlabs.org/project/linux-i2c/patch/20221124085448.3620240-1-yangyingliang@huawei.com/


Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 8c906cc0

drivers/i2c/i2c-core-base.c

+9 −4
Original line number Diff line number Diff line
@@ -932,6 +932,7 @@ struct i2c_client * 
i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info)

{

	struct i2c_client *client;

	bool need_put = false;

	int status;



	client = kzalloc(sizeof *client, GFP_KERNEL);
@@ -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:
@@ -1000,6 +1002,9 @@ 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:

	if (need_put)

		put_device(&client->dev);

	else

		kfree(client);

	return ERR_PTR(status);

}