Re: [PATCH] wifi: ath10k: Fix resource leak in ath10k_pci_init()

[Jeff Johnson <quic_jjohnson@quicinc.com>]

On 11/8/2022 5:38 AM, Xiu Jianfeng wrote:
> When ath10k_ahb_init() fails, it does not unregister ath10k_pci_driver,
> which will cause a resource leak issue, call pci_unregister_driver() in
> the error path to fix this issue.
> 
> Fixes: 0b523ced9a3c ("ath10k: add basic skeleton to support ahb")
> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
> ---
>   drivers/net/wireless/ath/ath10k/pci.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
> index e56c6a6b1379..22f8f8b20762 100644
> --- a/drivers/net/wireless/ath/ath10k/pci.c
> +++ b/drivers/net/wireless/ath/ath10k/pci.c
> @@ -3800,8 +3800,10 @@ static int __init ath10k_pci_init(void)
>   		       ret);
>   
>   	ret = ath10k_ahb_init();
> -	if (ret)
> +	if (ret) {
>   		printk(KERN_ERR "ahb init failed: %d\n", ret);
> +		pci_unregister_driver(&ath10k_pci_driver);
> +	}
>   
>   	return ret;
>   }

imo neither the existing code nor the modified code is correct.

the driver is attempting to register to support two different buses.

if either of these is successful then ath10k_pci_init() should return 0 
so that hardware attached to the successful bus can be probed and supported.

only if both of these are unsuccessful should ath10k_pci_init() return 
an errno.

so I suggest
	int ret1, ret2;

	ret1 = pci_register_driver(&ath10k_pci_driver);
	if (ret1)
		printk(KERN_ERR "failed to register ath10k pci driver: %d\n",
		       ret1);

	ret2 = ath10k_ahb_init();
	if (ret2)
		printk(KERN_ERR "ahb init failed: %d\n", ret2);

	if (ret1 && ret2)
		return ret1;

	/* registered to at least one bus */
	return 0;
}