Messages in this thread Patch in this message | | | From | Jianglei Nie <> | Subject | [PATCH] net: arc_emac: Fix use after free in arc_mdio_probe() | Date | Tue, 8 Mar 2022 19:10:05 +0800 |
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If bus->state is equal to MDIOBUS_ALLOCATED, mdiobus_free(bus) will free the "bus". But bus->name is still used in the next line, which will lead to a use after free.
We can fix it by putting the bus->name in a local variable and then use the name in the error message without referring to bus to avoid the uaf.
Signed-off-by: Jianglei Nie <niejianglei2021@163.com> --- drivers/net/ethernet/arc/emac_mdio.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/arc/emac_mdio.c b/drivers/net/ethernet/arc/emac_mdio.c index 9acf589b1178..33fd63d227ef 100644 --- a/drivers/net/ethernet/arc/emac_mdio.c +++ b/drivers/net/ethernet/arc/emac_mdio.c @@ -134,6 +134,7 @@ int arc_mdio_probe(struct arc_emac_priv *priv) struct device_node *np = priv->dev->of_node; struct mii_bus *bus; int error; + const char *name = "Synopsys MII Bus"; bus = mdiobus_alloc(); if (!bus) @@ -142,7 +143,7 @@ int arc_mdio_probe(struct arc_emac_priv *priv) priv->bus = bus; bus->priv = priv; bus->parent = priv->dev; - bus->name = "Synopsys MII Bus"; + bus->name = name; bus->read = &arc_mdio_read; bus->write = &arc_mdio_write; bus->reset = &arc_mdio_reset; @@ -167,7 +168,7 @@ int arc_mdio_probe(struct arc_emac_priv *priv) if (error) { mdiobus_free(bus); return dev_err_probe(priv->dev, error, - "cannot register MDIO bus %s\n", bus->name); + "cannot register MDIO bus %s\n", name); } return 0; -- 2.25.1
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