From: Hugo Villeneuve Date: Thu, 18 Jan 2024 15:21:57 +0000 (-0500) Subject: serial: max310x: fix NULL pointer dereference in I2C instantiation X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0d27056c24efd3d63a03f3edfbcfc4827086b110;p=linux.git serial: max310x: fix NULL pointer dereference in I2C instantiation 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 Signed-off-by: Hugo Villeneuve Link: https://lore.kernel.org/r/20240118152213.2644269-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index f3a99daebdaa0..4a33fd950ed2b 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -1602,13 +1602,16 @@ 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,