From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johan Hovold Subject: [PATCH v2 7/9] net: stmmac: dwmac-sun8i: fix OF child-node lookup Date: Mon, 27 Aug 2018 10:21:51 +0200 Message-ID: <20180827082153.22537-8-johan@kernel.org> References: <20180827082153.22537-1-johan@kernel.org> Return-path: In-Reply-To: <20180827082153.22537-1-johan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Rob Herring , Greg Kroah-Hartman Cc: Frank Rowand , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , Corentin Labbe , Andrew Lunn , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , "David S . Miller" List-Id: devicetree@vger.kernel.org Use the new of_get_compatible_child() helper to lookup the mdio-internal child node instead of using of_find_compatible_node(), which searches the entire tree from a given start node and thus can return an unrelated (i.e. non-child) node. This also addresses a potential use-after-free (e.g. after probe deferral) as the tree-wide helper drops a reference to its first argument (i.e. the mdio-mux node). Fortunately, this was inadvertently balanced by a failure to drop the mdio-mux reference after lookup. While at it, also fix the related mdio-internal- and phy-node reference leaks. Fixes: 634db83b8265 ("net: stmmac: dwmac-sun8i: Handle integrated/external MDIOs") Cc: Corentin Labbe Cc: Andrew Lunn Cc: Giuseppe Cavallaro Cc: Alexandre Torgue Cc: Jose Abreu Cc: David S. Miller Signed-off-by: Johan Hovold --- drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c index f9a61f90cfbc..0f660af01a4b 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c @@ -714,8 +714,9 @@ static int get_ephy_nodes(struct stmmac_priv *priv) return -ENODEV; } - mdio_internal = of_find_compatible_node(mdio_mux, NULL, + mdio_internal = of_get_compatible_child(mdio_mux, "allwinner,sun8i-h3-mdio-internal"); + of_node_put(mdio_mux); if (!mdio_internal) { dev_err(priv->device, "Cannot get internal_mdio node\n"); return -ENODEV; @@ -729,13 +730,20 @@ static int get_ephy_nodes(struct stmmac_priv *priv) gmac->rst_ephy = of_reset_control_get_exclusive(iphynode, NULL); if (IS_ERR(gmac->rst_ephy)) { ret = PTR_ERR(gmac->rst_ephy); - if (ret == -EPROBE_DEFER) + if (ret == -EPROBE_DEFER) { + of_node_put(iphynode); + of_node_put(mdio_internal); return ret; + } continue; } dev_info(priv->device, "Found internal PHY node\n"); + of_node_put(iphynode); + of_node_put(mdio_internal); return 0; } + + of_node_put(mdio_internal); return -ENODEV; } -- 2.18.0