Subject: [PATCH] agp/uninorth: fix a memleak in create_gatt_table

From: Denis Kirjanov <[email-masked]>
Date: Fri, 12 Jun 2015 09:57:11 +0300

Fix the memory leak in create_gatt_table:
we've lost a kfree on the exit path for the pages array allocated
in uninorth_create_gatt_table

Signed-off-by: Denis Kirjanov <[email-masked]>
---
 drivers/char/agp/uninorth-agp.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/char/agp/uninorth-agp.c b/drivers/char/agp/uninorth-agp.c
index a56ee9b..0575544 100644
--- a/drivers/char/agp/uninorth-agp.c
+++ b/drivers/char/agp/uninorth-agp.c
@@ -361,6 +361,10 @@ static int agp_uninorth_resume(struct pci_dev *pdev)
 }
 #endif /* CONFIG_PM */
 
+static struct {
+	struct page **pages_arr;
+} uninorth_priv;
+
 static int uninorth_create_gatt_table(struct agp_bridge_data *bridge)
 {
 	char *table;
@@ -371,7 +375,6 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge)
 	int i;
 	void *temp;
 	struct page *page;
-	struct page **pages;
 
 	/* We can't handle 2 level gatt's */
 	if (bridge->driver->size_type == LVL2_APER_SIZE)
@@ -400,8 +403,8 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge)
 	if (table == NULL)
 		return -ENOMEM;
 
-	pages = kmalloc((1 << page_order) * sizeof(struct page*), GFP_KERNEL);
-	if (pages == NULL)
+	uninorth_priv.pages_arr = kmalloc((1 << page_order) * sizeof(struct page*), GFP_KERNEL);
+	if (uninorth_priv.pages_arr == NULL)
 		goto enomem;
 
 	table_end = table + ((PAGE_SIZE * (1 << page_order)) - 1);
@@ -409,14 +412,14 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge)
 	for (page = virt_to_page(table), i = 0; page <= virt_to_page(table_end);
 	     page++, i++) {
 		SetPageReserved(page);
-		pages[i] = page;
+		uninorth_priv.pages_arr[i] = page;
 	}
 
 	bridge->gatt_table_real = (u32 *) table;
 	/* Need to clear out any dirty data still sitting in caches */
 	flush_dcache_range((unsigned long)table,
 			   (unsigned long)table_end + 1);
-	bridge->gatt_table = vmap(pages, (1 << page_order), 0, PAGE_KERNEL_NCG);
+	bridge->gatt_table = vmap(uninorth_priv.pages_arr, (1 << page_order), 0, PAGE_KERNEL_NCG);
 
 	if (bridge->gatt_table == NULL)
 		goto enomem;
@@ -434,7 +437,7 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge)
 	return 0;
 
 enomem:
-	kfree(pages);
+	kfree(uninorth_priv.pages_arr);
 	if (table)
 		free_pages((unsigned long)table, page_order);
 	return -ENOMEM;
@@ -456,6 +459,7 @@ static int uninorth_free_gatt_table(struct agp_bridge_data *bridge)
 	 */
 
 	vunmap(bridge->gatt_table);
+	kfree(uninorth_priv.pages_arr);
 	table = (char *) bridge->gatt_table_real;
 	table_end = table + ((PAGE_SIZE * (1 << page_order)) - 1);
 
-- 
2.4.0