[PATCH net] net: gianfar: dispose irq mappings on probe failure and device removal

[Rosen Penev <rosenp@gmail.com>]

irq_of_parse_and_map() creates irqdomain mappings that should be
balanced with irq_dispose_mapping(). The driver never called
irq_dispose_mapping(), leaking mappings on probe failure and
device removal.

Fix by adding irq_dispose_mapping() in free_gfar_dev() and
expanding its loop from priv->num_grps to MAXGROUPS so the
error path also catches partially-initialized groups. All
irqinfo pointers are pre-initialized to NULL in gfar_of_init(),
making the NULL-guarded walk in free_gfar_dev() safe for every
scenario.

gfar_parse_group() itself is left as a simple parse function
with no resource management; cleanup is centralized in the
caller's error path.

Assisted-by: opencode:big-pickle
Fixes: b31a1d8b4151 ("gianfar: Convert gianfar to an of_platform_driver")
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/net/ethernet/freescale/gianfar.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 3271de5844f8..89215e1ddc2d 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -469,10 +469,13 @@ static void free_gfar_dev(struct gfar_private *priv)
 {
 	int i, j;
 
-	for (i = 0; i < priv->num_grps; i++)
+	for (i = 0; i < MAXGROUPS; i++)
 		for (j = 0; j < GFAR_NUM_IRQS; j++) {
-			kfree(priv->gfargrp[i].irqinfo[j]);
-			priv->gfargrp[i].irqinfo[j] = NULL;
+			if (priv->gfargrp[i].irqinfo[j]) {
+				irq_dispose_mapping(priv->gfargrp[i].irqinfo[j]->irq);
+				kfree(priv->gfargrp[i].irqinfo[j]);
+				priv->gfargrp[i].irqinfo[j] = NULL;
+			}
 		}
 
 	free_netdev(priv->ndev);
@@ -616,7 +619,7 @@ static phy_interface_t gfar_get_interface(struct net_device *dev)
 static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 {
 	const char *model;
-	int err = 0, i;
+	int err = 0, i, j;
 	phy_interface_t interface;
 	struct net_device *dev = NULL;
 	struct gfar_private *priv = NULL;
@@ -702,8 +705,11 @@ static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 	priv->rx_list.count = 0;
 	mutex_init(&priv->rx_queue_access);
 
-	for (i = 0; i < MAXGROUPS; i++)
+	for (i = 0; i < MAXGROUPS; i++) {
 		priv->gfargrp[i].regs = NULL;
+		for (j = 0; j < GFAR_NUM_IRQS; j++)
+			priv->gfargrp[i].irqinfo[j] = NULL;
+	}
 
 	/* Parse and initialize group specific information */
 	if (priv->mode == MQ_MG_MODE) {
-- 
2.54.0