Commit b45ef5db authored Apr 13, 2021 by Michael Zaidman Committed by Jiri Kosina May 05, 2021

HID: ft260: check data size in ft260_smbus_write()



The SMbus block transaction limits the number of bytes transferred to 32,
but nothing prevents a user from specifying via ioctl a larger data size
than the ft260 can handle in a single transfer.

i2cdev_ioctl_smbus()
   --> i2c_smbus_xfer
       --> __i2c_smbus_xfer
           --> ft260_smbus_xfer
               --> ft260_smbus_write

This patch adds data size checking in the ft260_smbus_write().

Fixes: 98189a0adfa0 ("HID: ft260: add usb hid to i2c host bridge driver")
Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

parent b0d713c6

drivers/hid/hid-ft260.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -201,7 +201,7 @@ struct ft260_i2c_write_request_report {
		u8 address; /* 7-bit I2C address */
		u8 flag; /* I2C transaction condition */
		u8 length; /* data payload length */
		u8 data[60]; /* data payload */
		u8 data[FT260_WR_DATA_MAX]; /* data payload */
		} __packed;

		struct ft260_i2c_read_request_report {
		@@ -429,6 +429,9 @@ static int ft260_smbus_write(struct ft260_device *dev, u8 addr, u8 cmd,
		struct ft260_i2c_write_request_report *rep =
		(struct ft260_i2c_write_request_report *)dev->write_buf;

		if (data_len >= sizeof(rep->data))
		return -EINVAL;

		rep->address = addr;
		rep->data[0] = cmd;
		rep->length = data_len + 1;