idpf: avoid vport access in idpf_get_link_ksettings

BugLink: https://bugs.launchpad.net/bugs/2100292

commit 81d2fb4c7c18a3b36ba3e00b9d5b753107472d75 upstream.

When the device control plane is removed or the platform
running device control plane is rebooted, a reset is detected
on the driver. On driver reset, it releases the resources and
waits for the reset to complete. If the reset fails, it takes
the error path and releases the vport lock. At this time if the
monitoring tools tries to access link settings, it call traces
for accessing released vport pointer.

To avoid it, move link_speed_mbps to netdev_priv structure
which removes the dependency on vport pointer and the vport lock
in idpf_get_link_ksettings. Also use netif_carrier_ok()
to check the link status and adjust the offsetof to use link_up
instead of link_speed_mbps.

Fixes: 02cbfba1ad ("idpf: add ethtool callbacks")
Cc: stable@vger.kernel.org # 6.7+
Reviewed-by: Tarun K Singh <tarun.k.singh@intel.com>
Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[koichiroden: dropped changes on idpf_lib.c and adjusted context
due to missing commits:
bcbedf253e91 ("idpf: cleanup virtchnl cruft")
43b67308df98 ("idpf: refactor remaining virtchnl messages")]
CVE-2024-50274
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/net/ethernet/intel/idpf/idpf.h

@@ -144,6 +144,7 @@ enum idpf_vport_state {
  * @adapter: Adapter back pointer
  * @vport: Vport back pointer
  * @vport_id: Vport identifier
+ * @link_speed_mbps: Link speed in mbps
  * @vport_idx: Relative vport index
  * @state: See enum idpf_vport_state
  * @netstats: Packet and byte stats
@@ -153,6 +154,7 @@ struct idpf_netdev_priv {
 	struct idpf_adapter *adapter;
 	struct idpf_vport *vport;
 	u32 vport_id;
+	u32 link_speed_mbps;
 	u16 vport_idx;
 	enum idpf_vport_state state;
 	struct rtnl_link_stats64 netstats;
@@ -356,7 +358,6 @@ struct idpf_port_stats {
  * @tx_itr_profile: TX profiles for Dynamic Interrupt Moderation
  * @port_stats: per port csum, header split, and other offload stats
  * @link_up: True if link is up
- * @link_speed_mbps: Link speed in mbps
  * @vc_msg: Virtchnl message buffer
  * @vc_state: Virtchnl message state
  * @vchnl_wq: Wait queue for virtchnl messages
@@ -405,7 +406,6 @@ struct idpf_vport {
 	struct idpf_port_stats port_stats;
 
 	bool link_up;
-	u32 link_speed_mbps;
 
 	char vc_msg[IDPF_CTLQ_MAX_BUF_LEN];
 	DECLARE_BITMAP(vc_state, IDPF_VC_NBITS);

drivers/net/ethernet/intel/idpf/idpf_ethtool.c

@@ -1310,24 +1310,19 @@ static void idpf_set_msglevel(struct net_device *netdev, u32 data)
 static int idpf_get_link_ksettings(struct net_device *netdev,
 				   struct ethtool_link_ksettings *cmd)
 {
-	struct idpf_vport *vport;
-
-	idpf_vport_ctrl_lock(netdev);
-	vport = idpf_netdev_to_vport(netdev);
+	struct idpf_netdev_priv *np = netdev_priv(netdev);
 
 	ethtool_link_ksettings_zero_link_mode(cmd, supported);
 	cmd->base.autoneg = AUTONEG_DISABLE;
 	cmd->base.port = PORT_NONE;
-	if (vport->link_up) {
+	if (netif_carrier_ok(netdev)) {
 		cmd->base.duplex = DUPLEX_FULL;
-		cmd->base.speed = vport->link_speed_mbps;
+		cmd->base.speed = np->link_speed_mbps;
 	} else {
 		cmd->base.duplex = DUPLEX_UNKNOWN;
 		cmd->base.speed = SPEED_UNKNOWN;
 	}
 
-	idpf_vport_ctrl_unlock(netdev);
-
 	return 0;
 }
 

drivers/net/ethernet/intel/idpf/idpf_virtchnl.c

@@ -23,7 +23,7 @@ static void idpf_recv_event_msg(struct idpf_vport *vport,
 
 	switch (event) {
 	case VIRTCHNL2_EVENT_LINK_CHANGE:
-		vport->link_speed_mbps = le32_to_cpu(v2e->link_speed);
+		np->link_speed_mbps = le32_to_cpu(v2e->link_speed);
 		link_status = v2e->link_status;
 
 		if (vport->link_up == link_status)