[PATCH v1] scsi: be2iscsi: Add length check when parsing nlattrs

[Lin Ma]

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.

This patch adds the nla_len check before accessing the nlattr data and
error 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@xxxxxxxxxx>
---
 drivers/scsi/be2iscsi/be_iscsi.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/scsi/be2iscsi/be_iscsi.c b/drivers/scsi/be2iscsi/be_iscsi.c
index 8aeaddc93b16..8d374ae863ba 100644
--- a/drivers/scsi/be2iscsi/be_iscsi.c
+++ b/drivers/scsi/be2iscsi/be_iscsi.c
@@ -450,6 +450,10 @@ int beiscsi_iface_set_param(struct Scsi_Host *shost,
 	}
 
 	nla_for_each_attr(attrib, data, dt_len, rm_len) {
+		/* ignore nla_type as it is never used */
+		if (nla_len(attrib) < sizeof(*iface_param))
+			return -EINVAL;
+
 		iface_param = nla_data(attrib);
 
 		if (iface_param->param_type != ISCSI_NET_PARAM)
-- 
2.17.1