From: Ioana Ciornei <ioana.ciornei@nxp.com>
Date: Thu, 11 Feb 2021 21:51:22 +0200
Subject: dpaa2-eth: fix memory leak in XDP_REDIRECT

Git-commit: e12be9139cca26d689fe1a9257054b76752f725b
Patch-mainline: v5.12-rc1
References: git-fixes

If xdp_do_redirect() fails, the calling driver should handle recycling
or freeing of the page associated with the frame. The dpaa2-eth driver
didn't do either of them and just incremented a counter.
Fix this by trying to DMA map back the page and recycle it or, if the
mapping fails, just free it.

Fixes: d678be1dc1ec ("dpaa2-eth: add XDP_REDIRECT support")
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -335,10 +335,20 @@ static u32 run_xdp(struct dpaa2_eth_priv
 		ch->buf_count--;
 		xdp.data_hard_start = vaddr;
 		err = xdp_do_redirect(priv->net_dev, &xdp, xdp_prog);
-		if (unlikely(err))
+		if (unlikely(err)) {
+			addr = dma_map_page(priv->net_dev->dev.parent,
+					    virt_to_page(vaddr), 0,
+					    priv->rx_buf_size, DMA_BIDIRECTIONAL);
+			if (unlikely(dma_mapping_error(priv->net_dev->dev.parent, addr))) {
+				free_pages((unsigned long)vaddr, 0);
+			} else {
+				ch->buf_count++;
+				xdp_release_buf(priv, ch, addr);
+			}
 			ch->stats.xdp_drop++;
-		else
+		} else {
 			ch->stats.xdp_redirect++;
+		}
 		break;
 	}