--- /dev/null
+From ec98ea7070e94cc25a422ec97d1421e28d97b7ee Mon Sep 17 00:00:00 2001
+From: Chris Leech <cleech@redhat.com>
+Date: Tue, 23 Feb 2021 18:00:17 -0800
+Subject: scsi: iscsi: Ensure sysfs attributes are limited to PAGE_SIZE
+
+From: Chris Leech <cleech@redhat.com>
+
+commit ec98ea7070e94cc25a422ec97d1421e28d97b7ee upstream.
+
+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>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/scsi/libiscsi.c | 148 ++++++++++++++++++------------------
+ drivers/scsi/scsi_transport_iscsi.c | 25 +++---
+ 2 files changed, 90 insertions(+), 83 deletions(-)
+
+--- a/drivers/scsi/libiscsi.c
++++ b/drivers/scsi/libiscsi.c
+@@ -3338,125 +3338,125 @@ int iscsi_session_get_param(struct iscsi
+
+ 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;
+@@ -3488,16 +3488,16 @@ int iscsi_conn_get_addr_param(struct soc
+ 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:
+@@ -3516,88 +3516,88 @@ int iscsi_conn_get_param(struct iscsi_cl
+
+ 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;
+@@ -3615,13 +3615,13 @@ int iscsi_host_get_param(struct Scsi_Hos
+
+ 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;
+--- a/drivers/scsi/scsi_transport_iscsi.c
++++ b/drivers/scsi/scsi_transport_iscsi.c
+@@ -135,7 +135,8 @@ show_transport_handle(struct device *dev
+
+ 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);
+
+@@ -2886,6 +2887,9 @@ iscsi_set_param(struct iscsi_transport *
+ 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)
+@@ -3033,6 +3037,9 @@ iscsi_set_host_param(struct iscsi_transp
+ 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",
+@@ -3966,7 +3973,7 @@ static ssize_t show_conn_state(struct de
+ 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);
+@@ -4194,7 +4201,7 @@ show_priv_session_state(struct device *d
+ 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);
+@@ -4203,7 +4210,7 @@ show_priv_session_creator(struct device
+ 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);
+@@ -4212,7 +4219,7 @@ show_priv_session_target_id(struct devic
+ 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);
+@@ -4225,8 +4232,8 @@ show_priv_session_##field(struct device
+ 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) \
--- /dev/null
+From 882213990d32fd224340a4533f6318dd152be4b2 Mon Sep 17 00:00:00 2001
+From: Juergen Gross <jgross@suse.com>
+Date: Wed, 24 Feb 2021 16:03:08 +0100
+Subject: xen: fix p2m size in dom0 for disabled memory hotplug case
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Juergen Gross <jgross@suse.com>
+
+commit 882213990d32fd224340a4533f6318dd152be4b2 upstream.
+
+Since commit 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated
+memory") foreign mappings are using guest physical addresses allocated
+via ZONE_DEVICE functionality.
+
+This will result in problems for the case of no balloon memory hotplug
+being configured, as the p2m list will only cover the initial memory
+size of the domain. Any ZONE_DEVICE allocated address will be outside
+the p2m range and thus a mapping can't be established with that memory
+address.
+
+Fix that by extending the p2m size for that case. At the same time add
+a check for a to be created mapping to be within the p2m limits in
+order to detect errors early.
+
+While changing a comment, remove some 32-bit leftovers.
+
+This is XSA-369.
+
+Fixes: 9e2369c06c8a18 ("xen: add helpers to allocate unpopulated memory")
+Cc: <stable@vger.kernel.org> # 5.9
+Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Reviewed-by: Jan Beulich <jbeulich@suse.com>
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/x86/include/asm/xen/page.h | 12 ++++++++++++
+ arch/x86/xen/p2m.c | 10 ++++++----
+ arch/x86/xen/setup.c | 25 +++----------------------
+ 3 files changed, 21 insertions(+), 26 deletions(-)
+
+--- a/arch/x86/include/asm/xen/page.h
++++ b/arch/x86/include/asm/xen/page.h
+@@ -87,6 +87,18 @@ clear_foreign_p2m_mapping(struct gnttab_
+ #endif
+
+ /*
++ * The maximum amount of extra memory compared to the base size. The
++ * main scaling factor is the size of struct page. At extreme ratios
++ * of base:extra, all the base memory can be filled with page
++ * structures for the extra memory, leaving no space for anything
++ * else.
++ *
++ * 10x seems like a reasonable balance between scaling flexibility and
++ * leaving a practically usable system.
++ */
++#define XEN_EXTRA_MEM_RATIO (10)
++
++/*
+ * Helper functions to write or read unsigned long values to/from
+ * memory, when the access may fault.
+ */
+--- a/arch/x86/xen/p2m.c
++++ b/arch/x86/xen/p2m.c
+@@ -416,6 +416,9 @@ void __init xen_vmalloc_p2m_tree(void)
+ xen_p2m_last_pfn = xen_max_p2m_pfn;
+
+ p2m_limit = (phys_addr_t)P2M_LIMIT * 1024 * 1024 * 1024 / PAGE_SIZE;
++ if (!p2m_limit && IS_ENABLED(CONFIG_XEN_UNPOPULATED_ALLOC))
++ p2m_limit = xen_start_info->nr_pages * XEN_EXTRA_MEM_RATIO;
++
+ vm.flags = VM_ALLOC;
+ vm.size = ALIGN(sizeof(unsigned long) * max(xen_max_p2m_pfn, p2m_limit),
+ PMD_SIZE * PMDS_PER_MID_PAGE);
+@@ -652,10 +655,9 @@ bool __set_phys_to_machine(unsigned long
+ pte_t *ptep;
+ unsigned int level;
+
+- if (unlikely(pfn >= xen_p2m_size)) {
+- BUG_ON(mfn != INVALID_P2M_ENTRY);
+- return true;
+- }
++ /* Only invalid entries allowed above the highest p2m covered frame. */
++ if (unlikely(pfn >= xen_p2m_size))
++ return mfn == INVALID_P2M_ENTRY;
+
+ /*
+ * The interface requires atomic updates on p2m elements.
+--- a/arch/x86/xen/setup.c
++++ b/arch/x86/xen/setup.c
+@@ -59,18 +59,6 @@ static struct {
+ } xen_remap_buf __initdata __aligned(PAGE_SIZE);
+ static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
+
+-/*
+- * The maximum amount of extra memory compared to the base size. The
+- * main scaling factor is the size of struct page. At extreme ratios
+- * of base:extra, all the base memory can be filled with page
+- * structures for the extra memory, leaving no space for anything
+- * else.
+- *
+- * 10x seems like a reasonable balance between scaling flexibility and
+- * leaving a practically usable system.
+- */
+-#define EXTRA_MEM_RATIO (10)
+-
+ static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
+
+ static void __init xen_parse_512gb(void)
+@@ -790,20 +778,13 @@ char * __init xen_memory_setup(void)
+ extra_pages += max_pages - max_pfn;
+
+ /*
+- * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
+- * factor the base size. On non-highmem systems, the base
+- * size is the full initial memory allocation; on highmem it
+- * is limited to the max size of lowmem, so that it doesn't
+- * get completely filled.
++ * Clamp the amount of extra memory to a XEN_EXTRA_MEM_RATIO
++ * factor the base size.
+ *
+ * Make sure we have no memory above max_pages, as this area
+ * isn't handled by the p2m management.
+- *
+- * In principle there could be a problem in lowmem systems if
+- * the initial memory is also very large with respect to
+- * lowmem, but we won't try to deal with that here.
+ */
+- extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
++ extra_pages = min3(XEN_EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
+ extra_pages, max_pages - max_pfn);
+ i = 0;
+ addr = xen_e820_table.entries[0].addr;
--- /dev/null
+From 8310b77b48c5558c140e7a57a702e7819e62f04e Mon Sep 17 00:00:00 2001
+From: Jan Beulich <jbeulich@suse.com>
+Date: Thu, 25 Feb 2021 16:34:43 +0100
+Subject: Xen/gnttab: handle p2m update errors on a per-slot basis
+
+From: Jan Beulich <jbeulich@suse.com>
+
+commit 8310b77b48c5558c140e7a57a702e7819e62f04e upstream.
+
+Bailing immediately from set_foreign_p2m_mapping() upon a p2m updating
+error leaves the full batch in an ambiguous state as far as the caller
+is concerned. Instead flags respective slots as bad, unmapping what
+was mapped there right away.
+
+HYPERVISOR_grant_table_op()'s return value and the individual unmap
+slots' status fields get used only for a one-time - there's not much we
+can do in case of a failure.
+
+Note that there's no GNTST_enomem or alike, so GNTST_general_error gets
+used.
+
+The map ops' handle fields get overwritten just to be on the safe side.
+
+This is part of XSA-367.
+
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Jan Beulich <jbeulich@suse.com>
+Reviewed-by: Juergen Gross <jgross@suse.com>
+Link: https://lore.kernel.org/r/96cccf5d-e756-5f53-b91a-ea269bfb9be0@suse.com
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/arm/xen/p2m.c | 35 +++++++++++++++++++++++++++++++----
+ arch/x86/xen/p2m.c | 44 +++++++++++++++++++++++++++++++++++++++++---
+ 2 files changed, 72 insertions(+), 7 deletions(-)
+
+--- a/arch/arm/xen/p2m.c
++++ b/arch/arm/xen/p2m.c
+@@ -93,12 +93,39 @@ int set_foreign_p2m_mapping(struct gntta
+ int i;
+
+ for (i = 0; i < count; i++) {
++ struct gnttab_unmap_grant_ref unmap;
++ int rc;
++
+ if (map_ops[i].status)
+ continue;
+- if (unlikely(!set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
+- map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) {
+- return -ENOMEM;
+- }
++ if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
++ map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT)))
++ continue;
++
++ /*
++ * Signal an error for this slot. This in turn requires
++ * immediate unmapping.
++ */
++ map_ops[i].status = GNTST_general_error;
++ unmap.host_addr = map_ops[i].host_addr,
++ unmap.handle = map_ops[i].handle;
++ map_ops[i].handle = ~0;
++ if (map_ops[i].flags & GNTMAP_device_map)
++ unmap.dev_bus_addr = map_ops[i].dev_bus_addr;
++ else
++ unmap.dev_bus_addr = 0;
++
++ /*
++ * Pre-populate the status field, to be recognizable in
++ * the log message below.
++ */
++ unmap.status = 1;
++
++ rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
++ &unmap, 1);
++ if (rc || unmap.status != GNTST_okay)
++ pr_err_once("gnttab unmap failed: rc=%d st=%d\n",
++ rc, unmap.status);
+ }
+
+ return 0;
+--- a/arch/x86/xen/p2m.c
++++ b/arch/x86/xen/p2m.c
+@@ -710,6 +710,8 @@ int set_foreign_p2m_mapping(struct gntta
+
+ for (i = 0; i < count; i++) {
+ unsigned long mfn, pfn;
++ struct gnttab_unmap_grant_ref unmap[2];
++ int rc;
+
+ /* Do not add to override if the map failed. */
+ if (map_ops[i].status != GNTST_okay ||
+@@ -727,10 +729,46 @@ int set_foreign_p2m_mapping(struct gntta
+
+ WARN(pfn_to_mfn(pfn) != INVALID_P2M_ENTRY, "page must be ballooned");
+
+- if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn)))) {
+- ret = -ENOMEM;
+- goto out;
++ if (likely(set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
++ continue;
++
++ /*
++ * Signal an error for this slot. This in turn requires
++ * immediate unmapping.
++ */
++ map_ops[i].status = GNTST_general_error;
++ unmap[0].host_addr = map_ops[i].host_addr,
++ unmap[0].handle = map_ops[i].handle;
++ map_ops[i].handle = ~0;
++ if (map_ops[i].flags & GNTMAP_device_map)
++ unmap[0].dev_bus_addr = map_ops[i].dev_bus_addr;
++ else
++ unmap[0].dev_bus_addr = 0;
++
++ if (kmap_ops) {
++ kmap_ops[i].status = GNTST_general_error;
++ unmap[1].host_addr = kmap_ops[i].host_addr,
++ unmap[1].handle = kmap_ops[i].handle;
++ kmap_ops[i].handle = ~0;
++ if (kmap_ops[i].flags & GNTMAP_device_map)
++ unmap[1].dev_bus_addr = kmap_ops[i].dev_bus_addr;
++ else
++ unmap[1].dev_bus_addr = 0;
+ }
++
++ /*
++ * Pre-populate both status fields, to be recognizable in
++ * the log message below.
++ */
++ unmap[0].status = 1;
++ unmap[1].status = 1;
++
++ rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
++ unmap, 1 + !!kmap_ops);
++ if (rc || unmap[0].status != GNTST_okay ||
++ unmap[1].status != GNTST_okay)
++ pr_err_once("gnttab unmap failed: rc=%d st0=%d st1=%d\n",
++ rc, unmap[0].status, unmap[1].status);
+ }
+
+ out:
projects / thirdparty / kernel / stable-queue.git / commitdiff
