RE: [PATCH v2 1/2] wifi: rtw88: fix incorrect error codes in rtw_debugfs_copy_from_user

[Ping-Ke Shih <pkshih@realtek.com>]

> -----Original Message-----
> From: Zhang Shurong <zhang_shurong@foxmail.com>
> Sent: Wednesday, April 26, 2023 12:24 AM
> To: tony0620emma@gmail.com
> Cc: kvalo@kernel.org; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com;
> linux-wireless@vger.kernel.org; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Zhang Shurong
> <zhang_shurong@foxmail.com>
> Subject: [PATCH v2 1/2] wifi: rtw88: fix incorrect error codes in rtw_debugfs_copy_from_user
> 
> If there is a failure during copy_from_user, rtw_debugfs_copy_from_user
> should return negative error code instead of a positive value count.
> 
> Fix this bug by returning correct error code. Moreover, the check
> of buffer against null is removed since it will be handled by
> copy_from_user.
> 
> Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>

Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>

> ---
>  drivers/net/wireless/realtek/rtw88/debug.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtw88/debug.c b/drivers/net/wireless/realtek/rtw88/debug.c
> index fa3d73b333ba..3da477e1ebd3 100644
> --- a/drivers/net/wireless/realtek/rtw88/debug.c
> +++ b/drivers/net/wireless/realtek/rtw88/debug.c
> @@ -183,8 +183,8 @@ static int rtw_debugfs_copy_from_user(char tmp[], int size,
> 
>         tmp_len = (count > size - 1 ? size - 1 : count);
> 
> -       if (!buffer || copy_from_user(tmp, buffer, tmp_len))
> -               return count;
> +       if (copy_from_user(tmp, buffer, tmp_len))
> +               return -EFAULT;
> 
>         tmp[tmp_len] = '\0';
> 
> --
> 2.40.0