This is a note to let you know that I've just added the patch titled
serial: max310x: fix NULL pointer dereference in I2C instantiation
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-max310x-fix-null-pointer-dereference-in-i2c-i.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 53b5d7a5dfd70e93b147d7fe7f1b040ce4d776e7
Author: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
Date: Thu Jan 18 10:21:57 2024 -0500
serial: max310x: fix NULL pointer dereference in I2C instantiation
[ Upstream commit 0d27056c24efd3d63a03f3edfbcfc4827086b110 ]
When trying to instantiate a max14830 device from userspace:
echo max14830 0x60 > /sys/bus/i2c/devices/i2c-2/new_device
we get the following error:
Unable to handle kernel NULL pointer dereference at virtual address...
...
Call trace:
max310x_i2c_probe+0x48/0x170 [max310x]
i2c_device_probe+0x150/0x2a0
...
Add check for validity of devtype to prevent the error, and abort probe
with a meaningful error message.
Fixes: 2e1f2d9a9bdb ("serial: max310x: implement I2C support")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240118152213.2644269-2-hugo@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index f70e2c277ab7e..198413df091b4 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -1635,13 +1635,16 @@ static unsigned short max310x_i2c_slave_addr(unsigned short addr,
static int max310x_i2c_probe(struct i2c_client *client)
{
- const struct max310x_devtype *devtype =
- device_get_match_data(&client->dev);
+ const struct max310x_devtype *devtype;
struct i2c_client *port_client;
struct regmap *regmaps[4];
unsigned int i;
u8 port_addr;
+ devtype = device_get_match_data(&client->dev);
+ if (!devtype)
+ return dev_err_probe(&client->dev, -ENODEV, "Failed to match device\n");
+
if (client->addr < devtype->slave_addr.min ||
client->addr > devtype->slave_addr.max)
return dev_err_probe(&client->dev, -EINVAL,
