scsi: be2iscsi: Add length check when parsing nlattrs

scsi: be2iscsi: Add length check when parsing nlattrs

beiscsi_iface_set_param() parses nlattr with nla_for_each_attr and assumes
every attributes can be viewed as struct iscsi_iface_param_info.

This is not true because there is no any nla_policy to validate the
attributes passed from the upper function iscsi_set_iface_params().

Add the nla_len check before accessing the nlattr data and return EINVAL if
the length check fails.

Fixes: 0e43895ec1f4 ("[SCSI] be2iscsi: adding functionality to change network settings using iscsiadm")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Link: https://lore.kernel.org/r/20230723075938.3713864-1-linma@zju.edu.cn
Reviewed-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>