[PATCH] i2c: core: Fix possible memleak in i2c_new_client_device()

Yang Yingliang
2021-10-15T09:48:03Z

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

In error path after calling i2c_dev_set_name(), the put_device()
should be used to give up the device reference, then the name
allocated in dev_set_name() will be freed in kobject_cleanup().

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
drivers/i2c/i2c-core-base.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 54964fbe3f03..190d4fd5e594 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1047,8 +1047,6 @@ i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *inf
client->dev.of_node = of_node_get(info->of_node);
client->dev.fwnode = info->fwnode;

- i2c_dev_set_name(adap, client, info);
-
if (info->swnode) {
status = device_add_software_node(&client->dev, info->swnode);
if (status) {
@@ -1059,17 +1057,20 @@ 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;
+ if (status) {
+ device_remove_software_node(&client->dev);
+ of_node_put(info->of_node);
+ put_device(&client->dev);
+ return ERR_PTR(status);
+ }

dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
client->name, dev_name(&client->dev));

return client;

-out_remove_swnode:
- device_remove_software_node(&client->dev);
out_err_put_of_node:
of_node_put(info->of_node);
out_err:
--
2.25.1