Re: [PATCH v5] staging: rtl8723bs: Add error handling for sd_read()

[Greg KH]

On Sun, Apr 06, 2025 at 10:35:13AM +0800, Wentao Liang wrote:
> The sdio_read32() calls sd_read(), but does not handle the error if
> sd_read() fails. This could lead to subsequent operations processing
> invalid data. A proper implementation can be found in sdio_readN().

Great, why not use that instead?

> Add error handling for the sd_read() to free tmpbuf and return error
> code if sd_read() fails. This ensure that the memcpy() is only performed
> when the read operation is successful.
> 
> Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
> Cc: stable@xxxxxxxxxxxxxxx # v4.12+
> Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
> ---
> v5: Fix error code
> v4: Add change log and fix error code
> v3: Add Cc flag
> v2: Change code to initialize val
> 
>  drivers/staging/rtl8723bs/hal/sdio_ops.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/rtl8723bs/hal/sdio_ops.c b/drivers/staging/rtl8723bs/hal/sdio_ops.c
> index 21e9f1858745..d79d41727042 100644
> --- a/drivers/staging/rtl8723bs/hal/sdio_ops.c
> +++ b/drivers/staging/rtl8723bs/hal/sdio_ops.c
> @@ -185,7 +185,12 @@ static u32 sdio_read32(struct intf_hdl *intfhdl, u32 addr)
>  			return SDIO_ERR_VAL32;
>  
>  		ftaddr &= ~(u16)0x3;
> -		sd_read(intfhdl, ftaddr, 8, tmpbuf);
> +		err = sd_read(intfhdl, ftaddr, 8, tmpbuf);
> +		if (err) {
> +			kfree(tmpbuf);
> +			return SDIO_ERR_VAL32;

Why isn't the error that you get from the lower levels being returned
here instead?  Throwing that away feels wrong, don't you think?

thanks,

greg k-h