Re: [PATCH] crypto: qat - uninitialized variable in adf_hb_error_inject_write()

["Cabiddu, Giovanni" <giovanni.cabiddu@intel.com>]

On Tue, Feb 13, 2024 at 09:09:41PM +0300, Dan Carpenter wrote:
> There are a few issues in this code.  If *ppos is non-zero then the
> first part of the buffer is not initialized.  We never initialize the
> last character of the buffer.  The return is not checked so it's
> possible that none of the buffer is initialized.
Thanks Dan.
> 
> This is debugfs code which is root only and the impact of these bugs is
> very small.  However, it's still worth fixing.  To fix this:
> 1) Check that *ppos is zero.
> 2) Use copy_from_user() instead of simple_write_to_buffer().
> 3) Explicitly add a NUL terminator.
> 
> Fixes: e2b67859ab6e ("crypto: qat - add heartbeat error simulator")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
>  .../crypto/intel/qat/qat_common/adf_heartbeat_dbgfs.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/crypto/intel/qat/qat_common/adf_heartbeat_dbgfs.c b/drivers/crypto/intel/qat/qat_common/adf_heartbeat_dbgfs.c
> index 5cd6c2d6f90a..cccdff24b48d 100644
> --- a/drivers/crypto/intel/qat/qat_common/adf_heartbeat_dbgfs.c
> +++ b/drivers/crypto/intel/qat/qat_common/adf_heartbeat_dbgfs.c
> @@ -160,16 +160,17 @@ static ssize_t adf_hb_error_inject_write(struct file *file,
>  					 size_t count, loff_t *ppos)
>  {
>  	struct adf_accel_dev *accel_dev = file->private_data;
> -	size_t written_chars;
>  	char buf[3];
>  	int ret;
>  
>  	/* last byte left as string termination */
> -	if (count != 2)
> +	if (*ppos != 0 || count != 2)
Is this alone not sufficient to fix the problem? Probably I'm missing
something.
The function just checks the first character in buf.

Anyway, looks correct to me.
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>

Regards,

-- 
Giovanni