Re: [PATCH v2 4/4] s390x: Fix SCLP return code when buffer too small

[David Hildenbrand]

On 27.09.19 15:33, Claudio Imbrenda wrote:
> Return the correct error code when the SCCB buffer is too small to
> contain all of the output, for the Read SCP Information and
> Read CPU Information commands.

"s390x: sclp: Report insufficient SCCB length"

Reviewed-by: David Hildenbrand <address@hidden>

> 
> Signed-off-by: Claudio Imbrenda <address@hidden>
> Reviewed-by: Jason J. Herne <address@hidden>
> ---
>  hw/s390x/sclp.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
> index abb6e50..f57ce7b 100644
> --- a/hw/s390x/sclp.c
> +++ b/hw/s390x/sclp.c
> @@ -68,6 +68,12 @@ static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb)
>  
>      read_info->ibc_val = cpu_to_be32(s390_get_ibc_val());
>  
> +    if (be16_to_cpu(sccb->h.length) <
> +            (sizeof(ReadInfo) + cpu_count * sizeof(CPUEntry))) {
> +        sccb->h.response_code = 
> cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
> +        return;
> +    }
> +
>      /* Configuration Characteristic (Extension) */
>      s390_get_feat_block(S390_FEAT_TYPE_SCLP_CONF_CHAR,
>                           read_info->conf_char);
> @@ -118,6 +124,12 @@ static void sclp_read_cpu_info(SCLPDevice *sclp, SCCB 
> *sccb)
>      cpu_info->offset_configured = cpu_to_be16(offsetof(ReadCpuInfo, 
> entries));
>      cpu_info->nr_standby = cpu_to_be16(0);
>  
> +    if (be16_to_cpu(sccb->h.length) <
> +            (sizeof(ReadCpuInfo) + cpu_count * sizeof(CPUEntry))) {
> +        sccb->h.response_code = 
> cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
> +        return;
> +    }
> +
>      /* The standby offset is 16-byte for each CPU */
>      cpu_info->offset_standby = cpu_to_be16(cpu_info->offset_configured
>          + cpu_info->nr_configured*sizeof(CPUEntry));
> 


-- 

Thanks,

David / dhildenb