Re: [PATCH] fwctl: pds: Validate RPC input size before parsing

[Dave Jiang <dave.jiang@intel.com>]

On 5/16/26 11:22 PM, Heechan Kang wrote:
> The fwctl core allocates the device-specific RPC input buffer with
> fwctl_rpc.in_len and passes that buffer to the driver callback.
> 
> pdsfc_fw_rpc() casts the buffer to struct fwctl_rpc_pds and then calls
> pdsfc_validate_rpc(), which reads fields from that structure before
> checking that the input buffer is large enough to contain it. A short
> in_len can make pds_fwctl read beyond the allocation.
> 
> Reject pds RPC buffers that are smaller than struct fwctl_rpc_pds before
> parsing any pds-specific fields.
> 
> Fixes: 92c66ee829b9 ("pds_fwctl: add rpc and query support")
> Cc: stable@vger.kernel.org # v6.15+
> Signed-off-by: Heechan Kang <gganji11@naver.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/fwctl/pds/main.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/fwctl/pds/main.c b/drivers/fwctl/pds/main.c
> index 08872ee8422f..68fe254dd10a 100644
> --- a/drivers/fwctl/pds/main.c
> +++ b/drivers/fwctl/pds/main.c
> @@ -362,6 +362,9 @@ static void *pdsfc_fw_rpc(struct fwctl_uctx *uctx, enum fwctl_rpc_scope scope,
>  	void *out = NULL;
>  	int err;
>  
> +	if (in_len < sizeof(*rpc))
> +		return ERR_PTR(-EINVAL);
> +
>  	err = pdsfc_validate_rpc(pdsfc, rpc, scope);
>  	if (err)
>  		return ERR_PTR(err);