scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE

As the iSCSI parameters are exported back through sysfs, it should be
enforcing that they never are more than PAGE_SIZE (which should be more
than enough) before accepting updates through netlink.

Change all iSCSI sysfs attributes to use sysfs_emit().

Cc: stable@vger.kernel.org
Reported-by: Adam Nichols <adam@grimm-co.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Chris Leech <cleech@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 90 insertions, 83 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 7ad11e42306ded..04633e5157e96a 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -3430,125 +3430,125 @@ int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
 
 	switch(param) {
 	case ISCSI_PARAM_FAST_ABORT:
-		len = sprintf(buf, "%d\n", session->fast_abort);
+		len = sysfs_emit(buf, "%d\n", session->fast_abort);
 		break;
 	case ISCSI_PARAM_ABORT_TMO:
-		len = sprintf(buf, "%d\n", session->abort_timeout);
+		len = sysfs_emit(buf, "%d\n", session->abort_timeout);
 		break;
 	case ISCSI_PARAM_LU_RESET_TMO:
-		len = sprintf(buf, "%d\n", session->lu_reset_timeout);
+		len = sysfs_emit(buf, "%d\n", session->lu_reset_timeout);
 		break;
 	case ISCSI_PARAM_TGT_RESET_TMO:
-		len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
+		len = sysfs_emit(buf, "%d\n", session->tgt_reset_timeout);
 		break;
 	case ISCSI_PARAM_INITIAL_R2T_EN:
-		len = sprintf(buf, "%d\n", session->initial_r2t_en);
+		len = sysfs_emit(buf, "%d\n", session->initial_r2t_en);
 		break;
 	case ISCSI_PARAM_MAX_R2T:
-		len = sprintf(buf, "%hu\n", session->max_r2t);
+		len = sysfs_emit(buf, "%hu\n", session->max_r2t);
 		break;
 	case ISCSI_PARAM_IMM_DATA_EN:
-		len = sprintf(buf, "%d\n", session->imm_data_en);
+		len = sysfs_emit(buf, "%d\n", session->imm_data_en);
 		break;
 	case ISCSI_PARAM_FIRST_BURST:
-		len = sprintf(buf, "%u\n", session->first_burst);
+		len = sysfs_emit(buf, "%u\n", session->first_burst);
 		break;
 	case ISCSI_PARAM_MAX_BURST:
-		len = sprintf(buf, "%u\n", session->max_burst);
+		len = sysfs_emit(buf, "%u\n", session->max_burst);
 		break;
 	case ISCSI_PARAM_PDU_INORDER_EN:
-		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
+		len = sysfs_emit(buf, "%d\n", session->pdu_inorder_en);
 		break;
 	case ISCSI_PARAM_DATASEQ_INORDER_EN:
-		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
+		len = sysfs_emit(buf, "%d\n", session->dataseq_inorder_en);
 		break;
 	case ISCSI_PARAM_DEF_TASKMGMT_TMO:
-		len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
+		len = sysfs_emit(buf, "%d\n", session->def_taskmgmt_tmo);
 		break;
 	case ISCSI_PARAM_ERL:
-		len = sprintf(buf, "%d\n", session->erl);
+		len = sysfs_emit(buf, "%d\n", session->erl);
 		break;
 	case ISCSI_PARAM_TARGET_NAME:
-		len = sprintf(buf, "%s\n", session->targetname);
+		len = sysfs_emit(buf, "%s\n", session->targetname);
 		break;
 	case ISCSI_PARAM_TARGET_ALIAS:
-		len = sprintf(buf, "%s\n", session->targetalias);
+		len = sysfs_emit(buf, "%s\n", session->targetalias);
 		break;
 	case ISCSI_PARAM_TPGT:
-		len = sprintf(buf, "%d\n", session->tpgt);
+		len = sysfs_emit(buf, "%d\n", session->tpgt);
 		break;
 	case ISCSI_PARAM_USERNAME:
-		len = sprintf(buf, "%s\n", session->username);
+		len = sysfs_emit(buf, "%s\n", session->username);
 		break;
 	case ISCSI_PARAM_USERNAME_IN:
-		len = sprintf(buf, "%s\n", session->username_in);
+		len = sysfs_emit(buf, "%s\n", session->username_in);
 		break;
 	case ISCSI_PARAM_PASSWORD:
-		len = sprintf(buf, "%s\n", session->password);
+		len = sysfs_emit(buf, "%s\n", session->password);
 		break;
 	case ISCSI_PARAM_PASSWORD_IN:
-		len = sprintf(buf, "%s\n", session->password_in);
+		len = sysfs_emit(buf, "%s\n", session->password_in);
 		break;
 	case ISCSI_PARAM_IFACE_NAME:
-		len = sprintf(buf, "%s\n", session->ifacename);
+		len = sysfs_emit(buf, "%s\n", session->ifacename);
 		break;
 	case ISCSI_PARAM_INITIATOR_NAME:
-		len = sprintf(buf, "%s\n", session->initiatorname);
+		len = sysfs_emit(buf, "%s\n", session->initiatorname);
 		break;
 	case ISCSI_PARAM_BOOT_ROOT:
-		len = sprintf(buf, "%s\n", session->boot_root);
+		len = sysfs_emit(buf, "%s\n", session->boot_root);
 		break;
 	case ISCSI_PARAM_BOOT_NIC:
-		len = sprintf(buf, "%s\n", session->boot_nic);
+		len = sysfs_emit(buf, "%s\n", session->boot_nic);
 		break;
 	case ISCSI_PARAM_BOOT_TARGET:
-		len = sprintf(buf, "%s\n", session->boot_target);
+		len = sysfs_emit(buf, "%s\n", session->boot_target);
 		break;
 	case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
-		len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
+		len = sysfs_emit(buf, "%u\n", session->auto_snd_tgt_disable);
 		break;
 	case ISCSI_PARAM_DISCOVERY_SESS:
-		len = sprintf(buf, "%u\n", session->discovery_sess);
+		len = sysfs_emit(buf, "%u\n", session->discovery_sess);
 		break;
 	case ISCSI_PARAM_PORTAL_TYPE:
-		len = sprintf(buf, "%s\n", session->portal_type);
+		len = sysfs_emit(buf, "%s\n", session->portal_type);
 		break;
 	case ISCSI_PARAM_CHAP_AUTH_EN:
-		len = sprintf(buf, "%u\n", session->chap_auth_en);
+		len = sysfs_emit(buf, "%u\n", session->chap_auth_en);
 		break;
 	case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
-		len = sprintf(buf, "%u\n", session->discovery_logout_en);
+		len = sysfs_emit(buf, "%u\n", session->discovery_logout_en);
 		break;
 	case ISCSI_PARAM_BIDI_CHAP_EN:
-		len = sprintf(buf, "%u\n", session->bidi_chap_en);
+		len = sysfs_emit(buf, "%u\n", session->bidi_chap_en);
 		break;
 	case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
-		len = sprintf(buf, "%u\n", session->discovery_auth_optional);
+		len = sysfs_emit(buf, "%u\n", session->discovery_auth_optional);
 		break;
 	case ISCSI_PARAM_DEF_TIME2WAIT:
-		len = sprintf(buf, "%d\n", session->time2wait);
+		len = sysfs_emit(buf, "%d\n", session->time2wait);
 		break;
 	case ISCSI_PARAM_DEF_TIME2RETAIN:
-		len = sprintf(buf, "%d\n", session->time2retain);
+		len = sysfs_emit(buf, "%d\n", session->time2retain);
 		break;
 	case ISCSI_PARAM_TSID:
-		len = sprintf(buf, "%u\n", session->tsid);
+		len = sysfs_emit(buf, "%u\n", session->tsid);
 		break;
 	case ISCSI_PARAM_ISID:
-		len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
+		len = sysfs_emit(buf, "%02x%02x%02x%02x%02x%02x\n",
 			      session->isid[0], session->isid[1],
 			      session->isid[2], session->isid[3],
 			      session->isid[4], session->isid[5]);
 		break;
 	case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
-		len = sprintf(buf, "%u\n", session->discovery_parent_idx);
+		len = sysfs_emit(buf, "%u\n", session->discovery_parent_idx);
 		break;
 	case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
 		if (session->discovery_parent_type)
-			len = sprintf(buf, "%s\n",
+			len = sysfs_emit(buf, "%s\n",
 				      session->discovery_parent_type);
 		else
-			len = sprintf(buf, "\n");
+			len = sysfs_emit(buf, "\n");
 		break;
 	default:
 		return -ENOSYS;
@@ -3580,16 +3580,16 @@ int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 	case ISCSI_PARAM_CONN_ADDRESS:
 	case ISCSI_HOST_PARAM_IPADDRESS:
 		if (sin)
-			len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
+			len = sysfs_emit(buf, "%pI4\n", &sin->sin_addr.s_addr);
 		else
-			len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
+			len = sysfs_emit(buf, "%pI6\n", &sin6->sin6_addr);
 		break;
 	case ISCSI_PARAM_CONN_PORT:
 	case ISCSI_PARAM_LOCAL_PORT:
 		if (sin)
-			len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
+			len = sysfs_emit(buf, "%hu\n", be16_to_cpu(sin->sin_port));
 		else
-			len = sprintf(buf, "%hu\n",
+			len = sysfs_emit(buf, "%hu\n",
 				      be16_to_cpu(sin6->sin6_port));
 		break;
 	default:
@@ -3608,88 +3608,88 @@ int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
 
 	switch(param) {
 	case ISCSI_PARAM_PING_TMO:
-		len = sprintf(buf, "%u\n", conn->ping_timeout);
+		len = sysfs_emit(buf, "%u\n", conn->ping_timeout);
 		break;
 	case ISCSI_PARAM_RECV_TMO:
-		len = sprintf(buf, "%u\n", conn->recv_timeout);
+		len = sysfs_emit(buf, "%u\n", conn->recv_timeout);
 		break;
 	case ISCSI_PARAM_MAX_RECV_DLENGTH:
-		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
+		len = sysfs_emit(buf, "%u\n", conn->max_recv_dlength);
 		break;
 	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
-		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
+		len = sysfs_emit(buf, "%u\n", conn->max_xmit_dlength);
 		break;
 	case ISCSI_PARAM_HDRDGST_EN:
-		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
+		len = sysfs_emit(buf, "%d\n", conn->hdrdgst_en);
 		break;
 	case ISCSI_PARAM_DATADGST_EN:
-		len = sprintf(buf, "%d\n", conn->datadgst_en);
+		len = sysfs_emit(buf, "%d\n", conn->datadgst_en);
 		break;
 	case ISCSI_PARAM_IFMARKER_EN:
-		len = sprintf(buf, "%d\n", conn->ifmarker_en);
+		len = sysfs_emit(buf, "%d\n", conn->ifmarker_en);
 		break;
 	case ISCSI_PARAM_OFMARKER_EN:
-		len = sprintf(buf, "%d\n", conn->ofmarker_en);
+		len = sysfs_emit(buf, "%d\n", conn->ofmarker_en);
 		break;
 	case ISCSI_PARAM_EXP_STATSN:
-		len = sprintf(buf, "%u\n", conn->exp_statsn);
+		len = sysfs_emit(buf, "%u\n", conn->exp_statsn);
 		break;
 	case ISCSI_PARAM_PERSISTENT_PORT:
-		len = sprintf(buf, "%d\n", conn->persistent_port);
+		len = sysfs_emit(buf, "%d\n", conn->persistent_port);
 		break;
 	case ISCSI_PARAM_PERSISTENT_ADDRESS:
-		len = sprintf(buf, "%s\n", conn->persistent_address);
+		len = sysfs_emit(buf, "%s\n", conn->persistent_address);
 		break;
 	case ISCSI_PARAM_STATSN:
-		len = sprintf(buf, "%u\n", conn->statsn);
+		len = sysfs_emit(buf, "%u\n", conn->statsn);
 		break;
 	case ISCSI_PARAM_MAX_SEGMENT_SIZE:
-		len = sprintf(buf, "%u\n", conn->max_segment_size);
+		len = sysfs_emit(buf, "%u\n", conn->max_segment_size);
 		break;
 	case ISCSI_PARAM_KEEPALIVE_TMO:
-		len = sprintf(buf, "%u\n", conn->keepalive_tmo);
+		len = sysfs_emit(buf, "%u\n", conn->keepalive_tmo);
 		break;
 	case ISCSI_PARAM_LOCAL_PORT:
-		len = sprintf(buf, "%u\n", conn->local_port);
+		len = sysfs_emit(buf, "%u\n", conn->local_port);
 		break;
 	case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
-		len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
+		len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_stat);
 		break;
 	case ISCSI_PARAM_TCP_NAGLE_DISABLE:
-		len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
+		len = sysfs_emit(buf, "%u\n", conn->tcp_nagle_disable);
 		break;
 	case ISCSI_PARAM_TCP_WSF_DISABLE:
-		len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
+		len = sysfs_emit(buf, "%u\n", conn->tcp_wsf_disable);
 		break;
 	case ISCSI_PARAM_TCP_TIMER_SCALE:
-		len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
+		len = sysfs_emit(buf, "%u\n", conn->tcp_timer_scale);
 		break;
 	case ISCSI_PARAM_TCP_TIMESTAMP_EN:
-		len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
+		len = sysfs_emit(buf, "%u\n", conn->tcp_timestamp_en);
 		break;
 	case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
-		len = sprintf(buf, "%u\n", conn->fragment_disable);
+		len = sysfs_emit(buf, "%u\n", conn->fragment_disable);
 		break;
 	case ISCSI_PARAM_IPV4_TOS:
-		len = sprintf(buf, "%u\n", conn->ipv4_tos);
+		len = sysfs_emit(buf, "%u\n", conn->ipv4_tos);
 		break;
 	case ISCSI_PARAM_IPV6_TC:
-		len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
+		len = sysfs_emit(buf, "%u\n", conn->ipv6_traffic_class);
 		break;
 	case ISCSI_PARAM_IPV6_FLOW_LABEL:
-		len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
+		len = sysfs_emit(buf, "%u\n", conn->ipv6_flow_label);
 		break;
 	case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
-		len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
+		len = sysfs_emit(buf, "%u\n", conn->is_fw_assigned_ipv6);
 		break;
 	case ISCSI_PARAM_TCP_XMIT_WSF:
-		len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
+		len = sysfs_emit(buf, "%u\n", conn->tcp_xmit_wsf);
 		break;
 	case ISCSI_PARAM_TCP_RECV_WSF:
-		len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
+		len = sysfs_emit(buf, "%u\n", conn->tcp_recv_wsf);
 		break;
 	case ISCSI_PARAM_LOCAL_IPADDR:
-		len = sprintf(buf, "%s\n", conn->local_ipaddr);
+		len = sysfs_emit(buf, "%s\n", conn->local_ipaddr);
 		break;
 	default:
 		return -ENOSYS;
@@ -3707,13 +3707,13 @@ int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
 
 	switch (param) {
 	case ISCSI_HOST_PARAM_NETDEV_NAME:
-		len = sprintf(buf, "%s\n", ihost->netdev);
+		len = sysfs_emit(buf, "%s\n", ihost->netdev);
 		break;
 	case ISCSI_HOST_PARAM_HWADDRESS:
-		len = sprintf(buf, "%s\n", ihost->hwaddress);
+		len = sysfs_emit(buf, "%s\n", ihost->hwaddress);
 		break;
 	case ISCSI_HOST_PARAM_INITIATOR_NAME:
-		len = sprintf(buf, "%s\n", ihost->initiatorname);
+		len = sysfs_emit(buf, "%s\n", ihost->initiatorname);
 		break;
 	default:
 		return -ENOSYS;
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 69a1f55499ef9c..c1eff85a8976c5 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -135,7 +135,8 @@ show_transport_handle(struct device *dev, struct device_attribute *attr,
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
-	return sprintf(buf, "%llu\n", (unsigned long long)iscsi_handle(priv->iscsi_transport));
+	return sysfs_emit(buf, "%llu\n",
+		  (unsigned long long)iscsi_handle(priv->iscsi_transport));
 }
 static DEVICE_ATTR(handle, S_IRUGO, show_transport_handle, NULL);
 
@@ -145,7 +146,7 @@ show_transport_##name(struct device *dev, 				\
 		      struct device_attribute *attr,char *buf)		\
 {									\
 	struct iscsi_internal *priv = dev_to_iscsi_internal(dev);	\
-	return sprintf(buf, format"\n", priv->iscsi_transport->name);	\
+	return sysfs_emit(buf, format"\n", priv->iscsi_transport->name);\
 }									\
 static DEVICE_ATTR(name, S_IRUGO, show_transport_##name, NULL);
 
@@ -186,7 +187,7 @@ static ssize_t
 show_ep_handle(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct iscsi_endpoint *ep = iscsi_dev_to_endpoint(dev);
-	return sprintf(buf, "%llu\n", (unsigned long long) ep->id);
+	return sysfs_emit(buf, "%llu\n", (unsigned long long) ep->id);
 }
 static ISCSI_ATTR(ep, handle, S_IRUGO, show_ep_handle, NULL);
 
@@ -2883,6 +2884,9 @@ iscsi_set_param(struct iscsi_transport *transport, struct iscsi_uevent *ev)
 	struct iscsi_cls_session *session;
 	int err = 0, value = 0;
 
+	if (ev->u.set_param.len > PAGE_SIZE)
+		return -EINVAL;
+
 	session = iscsi_session_lookup(ev->u.set_param.sid);
 	conn = iscsi_conn_lookup(ev->u.set_param.sid, ev->u.set_param.cid);
 	if (!conn || !session)
@@ -3030,6 +3034,9 @@ iscsi_set_host_param(struct iscsi_transport *transport,
 	if (!transport->set_host_param)
 		return -ENOSYS;
 
+	if (ev->u.set_host_param.len > PAGE_SIZE)
+		return -EINVAL;
+
 	shost = scsi_host_lookup(ev->u.set_host_param.host_no);
 	if (!shost) {
 		printk(KERN_ERR "set_host_param could not find host no %u\n",
@@ -3963,7 +3970,7 @@ static ssize_t show_conn_state(struct device *dev,
 	    conn->state < ARRAY_SIZE(connection_state_names))
 		state = connection_state_names[conn->state];
 
-	return sprintf(buf, "%s\n", state);
+	return sysfs_emit(buf, "%s\n", state);
 }
 static ISCSI_CLASS_ATTR(conn, state, S_IRUGO, show_conn_state,
 			NULL);
@@ -4191,7 +4198,7 @@ show_priv_session_state(struct device *dev, struct device_attribute *attr,
 			char *buf)
 {
 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
-	return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
+	return sysfs_emit(buf, "%s\n", iscsi_session_state_name(session->state));
 }
 static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
 			NULL);
@@ -4200,7 +4207,7 @@ show_priv_session_creator(struct device *dev, struct device_attribute *attr,
 			char *buf)
 {
 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
-	return sprintf(buf, "%d\n", session->creator);
+	return sysfs_emit(buf, "%d\n", session->creator);
 }
 static ISCSI_CLASS_ATTR(priv_sess, creator, S_IRUGO, show_priv_session_creator,
 			NULL);
@@ -4209,7 +4216,7 @@ show_priv_session_target_id(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
 	struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
-	return sprintf(buf, "%d\n", session->target_id);
+	return sysfs_emit(buf, "%d\n", session->target_id);
 }
 static ISCSI_CLASS_ATTR(priv_sess, target_id, S_IRUGO,
 			show_priv_session_target_id, NULL);
@@ -4222,8 +4229,8 @@ show_priv_session_##field(struct device *dev, 				\
 	struct iscsi_cls_session *session = 				\
 			iscsi_dev_to_session(dev->parent);		\
 	if (session->field == -1)					\
-		return sprintf(buf, "off\n");				\
-	return sprintf(buf, format"\n", session->field);		\
+		return sysfs_emit(buf, "off\n");			\
+	return sysfs_emit(buf, format"\n", session->field);		\
 }
 
 #define iscsi_priv_session_attr_store(field)				\