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authorAhmad Fatoum <a.fatoum@pengutronix.de>2023-03-23 11:37:35 +0100
committerJakub Kicinski <kuba@kernel.org>2023-03-24 19:04:43 -0700
commitb93eb564869321d0dffaf23fcc5c88112ed62466 (patch)
tree5d34b8d66b28d059e7f118df48735257ef0620d5 /drivers/net
parent82e2c39f9ef78896e9b634dfd82dc042e6956bb7 (diff)
net: dsa: realtek: fix out-of-bounds access
The probe function sets priv->chip_data to (void *)priv + sizeof(*priv) with the expectation that priv has enough trailing space. However, only realtek-smi actually allocated this chip_data space. Do likewise in realtek-mdio to fix out-of-bounds accesses. These accesses likely went unnoticed so far, because of an (unused) buf[4096] member in struct realtek_priv, which caused kmalloc to round up the allocated buffer to a big enough size, so nothing of value was overwritten. With a different allocator (like in the barebox bootloader port of the driver) or with KASAN, the memory corruption becomes quickly apparent. Fixes: aac94001067d ("net: dsa: realtek: add new mdio interface for drivers") Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Luiz Angelo Daros de Luca <luizluca@gmail.com> Reviewed-by: Alvin Šipraga <alsi@bang-olufsen.dk> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de> Link: https://lore.kernel.org/r/20230323103735.2331786-1-a.fatoum@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/dsa/realtek/realtek-mdio.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/dsa/realtek/realtek-mdio.c b/drivers/net/dsa/realtek/realtek-mdio.c
index 3e54fac5f902..5a8fe707ca25 100644
--- a/drivers/net/dsa/realtek/realtek-mdio.c
+++ b/drivers/net/dsa/realtek/realtek-mdio.c
@@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/of_device.h>
+#include <linux/overflow.h>
#include <linux/regmap.h>
#include "realtek.h"
@@ -152,7 +153,9 @@ static int realtek_mdio_probe(struct mdio_device *mdiodev)
if (!var)
return -EINVAL;
- priv = devm_kzalloc(&mdiodev->dev, sizeof(*priv), GFP_KERNEL);
+ priv = devm_kzalloc(&mdiodev->dev,
+ size_add(sizeof(*priv), var->chip_data_sz),
+ GFP_KERNEL);
if (!priv)
return -ENOMEM;