From b45ef5db7bf268f6851bb5395d60301338374abc Mon Sep 17 00:00:00 2001 From: Michael Zaidman Date: Tue, 13 Apr 2021 18:12:00 +0300 Subject: [PATCH] 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 Reported-by: Dan Carpenter Signed-off-by: Jiri Kosina --- drivers/hid/hid-ft260.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index a575160..7a9ba98 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -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; -- 2.7.4