From 764cc5c6a6c9aeaae5c7d8fdfc60aa651733e1a5 Mon Sep 17 00:00:00 2001 From: DENG Qingfang Date: Sat, 4 Apr 2020 12:10:32 +0800 Subject: [PATCH] generic: mt7530: fix null pointer dereferencing in port5 setup The 2nd gmac of mediatek soc ethernet may not be connected to a PHY and a phy-handle isn't always available. Unfortunately, mt7530 dsa driver assumes that the 2nd gmac is always connected to switch port 5 and setup mt7530 according to phy address of 2nd gmac node, causing null pointer dereferencing when phy-handle isn't defined in dts. This commit fix this setup code by checking return value of of_parse_phandle before using it. Signed-off-by: DENG Qingfang --- ...ix-null-pointer-dereferencing-in-por.patch | 39 +++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 target/linux/generic/backport-5.4/746-stable-net-dsa-mt7530-fix-null-pointer-dereferencing-in-por.patch diff --git a/target/linux/generic/backport-5.4/746-stable-net-dsa-mt7530-fix-null-pointer-dereferencing-in-por.patch b/target/linux/generic/backport-5.4/746-stable-net-dsa-mt7530-fix-null-pointer-dereferencing-in-por.patch new file mode 100644 index 0000000000..1775bfb32c --- /dev/null +++ b/target/linux/generic/backport-5.4/746-stable-net-dsa-mt7530-fix-null-pointer-dereferencing-in-por.patch @@ -0,0 +1,39 @@ +From 0452800f6db4ed0a42ffb15867c0acfd68829f6a Mon Sep 17 00:00:00 2001 +From: Chuanhong Guo +Date: Fri, 3 Apr 2020 19:28:24 +0800 +Subject: net: dsa: mt7530: fix null pointer dereferencing in port5 setup +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +The 2nd gmac of mediatek soc ethernet may not be connected to a PHY +and a phy-handle isn't always available. +Unfortunately, mt7530 dsa driver assumes that the 2nd gmac is always +connected to switch port 5 and setup mt7530 according to phy address +of 2nd gmac node, causing null pointer dereferencing when phy-handle +isn't defined in dts. +This commit fix this setup code by checking return value of +of_parse_phandle before using it. + +Fixes: 38f790a80560 ("net: dsa: mt7530: Add support for port 5") +Signed-off-by: Chuanhong Guo +Reviewed-by: Vivien Didelot +Reviewed-by: Florian Fainelli +Tested-by: René van Dorst +Signed-off-by: David S. Miller +--- + drivers/net/dsa/mt7530.c | 3 +++ + 1 file changed, 3 insertions(+) + +--- a/drivers/net/dsa/mt7530.c ++++ b/drivers/net/dsa/mt7530.c +@@ -1411,6 +1411,9 @@ mt7530_setup(struct dsa_switch *ds) + continue; + + phy_node = of_parse_phandle(mac_np, "phy-handle", 0); ++ if (!phy_node) ++ continue; ++ + if (phy_node->parent == priv->dev->of_node->parent) { + interface = of_get_phy_mode(mac_np); + id = of_mdio_parse_addr(ds->dev, phy_node); -- 2.25.1