6.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hugo Villeneuve hvilleneuve@dimonoff.com
[ 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@vger.kernel.org Reviewed-by: Andy Shevchenko andy.shevchenko@gmail.com Signed-off-by: Hugo Villeneuve hvilleneuve@dimonoff.com Link: https://lore.kernel.org/r/20240118152213.2644269-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/max310x.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
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,