RE: [PATCH v3 04/16] cxl/pci: Handle excessive CDAT length

[Dan Williams <dan.j.williams@intel.com>]

Lukas Wunner wrote:
> If the length in the CDAT header is larger than the concatenation of the
> header and all table entries, then the CDAT exposed to user space
> contains trailing null bytes.
> 
> Not every consumer may be able to handle that.  Per Postel's robustness
> principle, "be liberal in what you accept" and silently reduce the
> cached length to avoid exposing those null bytes.
> 
> Fixes: c97006046c79 ("cxl/port: Read CDAT table")
> Tested-by: Ira Weiny <ira.weiny@intel.com>
> Signed-off-by: Lukas Wunner <lukas@wunner.de>
> Cc: stable@vger.kernel.org # v6.0+
> ---
>  Changes v2 -> v3:
>  * Newly added patch in v3
> 
>  drivers/cxl/core/pci.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
> index a3fb6bd68d17..c37c41d7acb6 100644
> --- a/drivers/cxl/core/pci.c
> +++ b/drivers/cxl/core/pci.c
> @@ -582,6 +582,9 @@ static int cxl_cdat_read_table(struct device *dev,
>  		}
>  	} while (entry_handle != CXL_DOE_TABLE_ACCESS_LAST_ENTRY);
>  
> +	/* Length in CDAT header may exceed concatenation of CDAT entries */
> +	cdat->length -= length;
> +

Looks good,

Reviewed-by: Dan Williams <dan.j.williams@intel.com>