[PATCH v4 2/3] powerpc/pseries: PLPKS SED Opal keystore support

[Elliott, Robert (Servers)]

> -----Original Message-----
> From: gjoyce at linux.vnet.ibm.com <gjoyce at linux.vnet.ibm.com>
> Sent: Friday, August 19, 2022 5:32 PM
> To: linux-block at vger.kernel.org
> Cc: linuxppc-dev at lists.ozlabs.org; jonathan.derrick at linux.dev;
> brking at linux.vnet.ibm.com; msuchanek at suse.de; mpe at ellerman.id.au;
> nayna at linux.ibm.com; axboe at kernel.dk; akpm at linux-foundation.org;
> gjoyce at linux.vnet.ibm.com; linux-efi at vger.kernel.org;
> keyrings at vger.kernel.org; dhowells at redhat.com; jarkko at kernel.org
> Subject: [PATCH v4 2/3] powerpc/pseries: PLPKS SED Opal keystore support
> 
> +++ b/arch/powerpc/platforms/pseries/plpks_sed_ops.c
...
> +struct plpks_sed_object_data {
> +	u_char version;
> +	u_char pad1[7];
> +	u_long authority;
> +	u_long range;
> +	u_int  key_len;
> +	u_char key[32];
> +};
...
> +/*
> + * Read the SED Opal key from PLPKS given the label
> + */
> +int sed_read_key(char *keyname, char *key, u_int *keylen)
> +{
...
> +	*keylen = be32_to_cpu(data->key_len);
> +
> +	if (var.data) {
> +		memcpy(key, var.data + offset, var.datalen - offset);
> +		key[*keylen] = '\0';

Is there a guarantee that key_len is always < sizeof key, or
does that need to be checked in more places?