Re: [PATCH] thunderbolt: Fix to check for kmemdup failure

[Mukesh Ojha]

On 3/19/2019 4:14 AM, Aditya Pakki wrote:
> Memory allocated via kmemdup might fail and return a NULL pointer.
> This patch adds a check on the return value of kmemdup and passes the
> error upstream.
>
> Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
> ---
>   drivers/thunderbolt/switch.c | 15 +++++++++++----
>   1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
> index cd96994dc094..c05d77073ee7 100644
> --- a/drivers/thunderbolt/switch.c
> +++ b/drivers/thunderbolt/switch.c
> @@ -1294,13 +1294,13 @@ int tb_switch_configure(struct tb_switch *sw)
>   	return tb_plug_events_active(sw, true);
>   }
>   
> -static void tb_switch_set_uuid(struct tb_switch *sw)
> +static int tb_switch_set_uuid(struct tb_switch *sw)
>   {
>   	u32 uuid[4];
>   	int cap;
>   
>   	if (sw->uuid)
> -		return;
> +		return 0;
>   
>   	/*
>   	 * The newer controllers include fused UUID as part of link
> @@ -1323,6 +1323,9 @@ static void tb_switch_set_uuid(struct tb_switch *sw)
>   	}
>   
>   	sw->uuid = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
> +	if (!sw->uuid)
> +		return -ENOMEM;
> +	return 0;
>   }
>   

Change looks good to me.

Reviewed-by: Mukesh Ojha <mojha@xxxxxxxxxxxxxx>

but, we should add check for `tb_sw_read ` this as well.


Cheers,
Mukesh


>   static int tb_switch_add_dma_port(struct tb_switch *sw)
> @@ -1372,7 +1375,9 @@ static int tb_switch_add_dma_port(struct tb_switch *sw)
>   
>   	if (status) {
>   		tb_sw_info(sw, "switch flash authentication failed\n");
> -		tb_switch_set_uuid(sw);
> +		ret = tb_switch_set_uuid(sw);
> +		if (ret)
> +			return ret;
>   		nvm_set_auth_status(sw, status);
>   	
>   
> @@ -1Reviewed-by: Andy Shevchenko<andriy.shevchenko@xxxxxxxxxxxxxxx>422,7 +1427,9 @@ int tb_switch_add(struct tb_switch *sw)
>   		}
>   		tb_sw_dbg(sw, "uid: %#llx\n", sw->uid);
>   
> -		tb_switch_set_uuid(sw);
> +		ret = tb_switch_set_uuid(sw);
> +		if (ret)
> +			return ret;
>   
>   		for (i = 0; i <= sw->config.max_port_number; i++) {
>   			if (sw->ports[i].disabled) {