[PATCH net] wwan_hwsim: fix possible memory leak in wwan_hwsim_dev_new()

[Yang Yingliang <yangyingliang@huawei.com>]

Inject fault while probing module, if device_register() fails,
but the refcount of kobject is not decreased to 0, the name
allocated in dev_set_name() is leaked. Fix this by calling
put_device(), so that name can be freed in callback function
kobject_cleanup().

unreferenced object 0xffff88810152ad20 (size 8):
  comm "modprobe", pid 252, jiffies 4294849206 (age 22.713s)
  hex dump (first 8 bytes):
    68 77 73 69 6d 30 00 ff                          hwsim0..
  backtrace:
    [<000000009c3504ed>] __kmalloc_node_track_caller+0x44/0x1b0
    [<00000000c0228a5e>] kvasprintf+0xb5/0x140
    [<00000000cff8c21f>] kvasprintf_const+0x55/0x180
    [<0000000055a1e073>] kobject_set_name_vargs+0x56/0x150
    [<000000000a80b139>] dev_set_name+0xab/0xe0

Fixes: f36a111a74e7 ("wwan_hwsim: WWAN device simulator")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/net/wwan/wwan_hwsim.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wwan/wwan_hwsim.c b/drivers/net/wwan/wwan_hwsim.c
index ff09a8cedf93..2397a903d8f5 100644
--- a/drivers/net/wwan/wwan_hwsim.c
+++ b/drivers/net/wwan/wwan_hwsim.c
@@ -311,7 +311,7 @@ static struct wwan_hwsim_dev *wwan_hwsim_dev_new(void)
 	return ERR_PTR(err);
 
 err_free_dev:
-	kfree(dev);
+	put_device(&dev->dev);
 
 	return ERR_PTR(err);
 }
-- 
2.25.1