[PATCH v2 2/3] net: lan966x: fix page pool and resources leak in error paths

[David Carlier <devnexen@gmail.com>]

lan966x_fdma_rx_alloc() creates a page pool but does not destroy it if
the subsequent fdma_alloc_coherent() call fails, leaking the pool and
leaving a dangling pointer in rx->page_pool.

Similarly, lan966x_fdma_init() frees the coherent DMA memory when
lan966x_fdma_tx_alloc() fails but does not destroy the page pool that
was successfully created by lan966x_fdma_rx_alloc(), leaking it.

Add the missing page_pool_destroy() calls in both error paths and
NULL-out rx->page_pool after destruction to avoid a dangling pointer.

Fixes: 11871aba1974 ("net: lan96x: Use page_pool API")
Cc: stable@vger.kernel.org
Signed-off-by: David Carlier <devnexen@gmail.com>
---
 drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
index 34bbcae2f068..b985ce64bb50 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c
@@ -120,8 +120,11 @@ static int lan966x_fdma_rx_alloc(struct lan966x_rx *rx)
 		return PTR_ERR(rx->page_pool);
 
 	err = fdma_alloc_coherent(lan966x->dev, fdma);
-	if (err)
+	if (err) {
+		page_pool_destroy(rx->page_pool);
+		rx->page_pool = NULL;
 		return err;
+	}
 
 	fdma_dcbs_init(fdma, FDMA_DCB_INFO_DATAL(fdma->db_size),
 		       FDMA_DCB_STATUS_INTR);
@@ -958,6 +961,7 @@ int lan966x_fdma_init(struct lan966x *lan966x)
 	err = lan966x_fdma_tx_alloc(&lan966x->tx);
 	if (err) {
 		fdma_free_coherent(lan966x->dev, &lan966x->rx.fdma);
+		page_pool_destroy(lan966x->rx.page_pool);
 		return err;
 	}
 
-- 
2.53.0