diff options
| author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2023-03-23 11:37:35 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-03-24 19:04:43 -0700 |
| commit | b93eb564869321d0dffaf23fcc5c88112ed62466 (patch) | |
| tree | 5d34b8d66b28d059e7f118df48735257ef0620d5 | |
| parent | 82e2c39f9ef78896e9b634dfd82dc042e6956bb7 (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>
| -rw-r--r-- | drivers/net/dsa/realtek/realtek-mdio.c | 5 |
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; |