[PATCH 3/3] irqchip/gic-v3-its: Free the page when gen_pool_add() fails

[Fuad Tabba]

When the ITT pool has no room, itt_alloc_pool() grows it by a page and
retries. gen_pool_add() fails when it cannot allocate its chunk
descriptor, but its return is ignored, so the page is leaked and the
retry allocates another page to leak, until an add succeeds or a page
allocation fails.

Free the page and fail the allocation instead.

Fixes: b08e2f42e86b5 ("irqchip/gic-v3-its: Share ITS tables with a non-trusted hypervisor")
Signed-off-by: Fuad Tabba <fuad.tabba@xxxxxxxxx>
---
 drivers/irqchip/irq-gic-v3-its.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 5c3ab9d30f6af..bdf7c81e60c76 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -276,7 +276,10 @@ static void *itt_alloc_pool(int node, int size)
 		if (!page)
 			break;
 
-		gen_pool_add(itt_pool, (unsigned long)page_address(page), PAGE_SIZE, node);
+		if (gen_pool_add(itt_pool, (unsigned long)page_address(page), PAGE_SIZE, node)) {
+			its_free_pages(page_address(page), 0);
+			break;
+		}
 	} while (!addr);
 
 	return (void *)addr;
-- 
2.47.3