net: hns: fix possible memory leak in hnae_ae_register()

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 0xffff00c01aba2100 (size 128):
  comm "systemd-udevd", pid 1259, jiffies 4294903284 (age 294.152s)
  hex dump (first 32 bytes):
    68 6e 61 65 30 00 00 00 18 21 ba 1a c0 00 ff ff  hnae0....!......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000034783f26>] slab_post_alloc_hook+0xa0/0x3e0
    [<00000000748188f2>] __kmem_cache_alloc_node+0x164/0x2b0
    [<00000000ab0743e8>] __kmalloc_node_track_caller+0x6c/0x390
    [<000000006c0ffb13>] kvasprintf+0x8c/0x118
    [<00000000fa27bfe1>] kvasprintf_const+0x60/0xc8
    [<0000000083e10ed7>] kobject_set_name_vargs+0x3c/0xc0
    [<000000000b87affc>] dev_set_name+0x7c/0xa0
    [<000000003fd8fe26>] hnae_ae_register+0xcc/0x190 [hnae]
    [<00000000fe97edc9>] hns_dsaf_ae_init+0x9c/0x108 [hns_dsaf]
    [<00000000c36ff1eb>] hns_dsaf_probe+0x548/0x748 [hns_dsaf]

Fixes: 6fe6611 ("net: add Hisilicon Network Subsystem hnae framework support")
Signed-off-by: Yang Yingliang <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Yang Yingliang

drivers/net/ethernet/hisilicon/hns/hnae.c

@@ -419,8 +419,10 @@ int hnae_ae_register(struct hnae_ae_dev *hdev, struct module *owner)
 	hdev->cls_dev.release = hnae_release;
 	(void)dev_set_name(&hdev->cls_dev, "hnae%d", hdev->id);
 	ret = device_register(&hdev->cls_dev);
-	if (ret)
+	if (ret) {
+		put_device(&hdev->cls_dev);
 		return ret;
+	}
 
 	__module_get(THIS_MODULE);