Patch "i2c: fix memleak in i2c_new_client_device()" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    i2c: fix memleak in i2c_new_client_device()

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     i2c-fix-memleak-in-i2c_new_client_device.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e926fd1d058af5bffbab4928f292e01d891b2e92
Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Date:   Fri Sep 29 11:19:52 2023 +0200

    i2c: fix memleak in i2c_new_client_device()
    
    [ Upstream commit 6af79f7fe748fe6a3c5c3a63d7f35981a82c2769 ]
    
    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@xxxxxxxxxx>
    Closes: http://patchwork.ozlabs.org/project/linux-i2c/patch/20221124085448.3620240-1-yangyingliang@xxxxxxxxxx/
    Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 60746652fd525..7f30bcceebaed 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);