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@xxxxxxxxxx>
> ---
> .../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@xxxxxxxxx>
Regards,
--
Giovanni
