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Commit a12b8ab8 authored by Alyssa Milburn's avatar Alyssa Milburn Committed by Mauro Carvalho Chehab
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[media] ttusb2: limit messages to buffer size 



Otherwise ttusb2_i2c_xfer can read or write beyond the end of static and
heap buffers.

Signed-off-by: default avatarAlyssa Milburn <amilburn@zall.org>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 5f2c467c

drivers/media/usb/dvb-usb/ttusb2.c

+19 −0
Original line number Diff line number Diff line
@@ -78,6 +78,9 @@ static int ttusb2_msg(struct dvb_usb_device *d, u8 cmd, 
	u8 *s, *r = NULL;

	int ret = 0;



	if (4 + rlen > 64)

		return -EIO;



	s = kzalloc(wlen+4, GFP_KERNEL);

	if (!s)

		return -ENOMEM;
@@ -381,6 +384,22 @@ static int ttusb2_i2c_xfer(struct i2c_adapter *adap,struct i2c_msg msg[],int num 
		write_read = i+1 < num && (msg[i+1].flags & I2C_M_RD);

		read = msg[i].flags & I2C_M_RD;



		if (3 + msg[i].len > sizeof(obuf)) {

			err("i2c wr len=%d too high", msg[i].len);

			break;

		}

		if (write_read) {

			if (3 + msg[i+1].len > sizeof(ibuf)) {

				err("i2c rd len=%d too high", msg[i+1].len);

				break;

			}

		} else if (read) {

			if (3 + msg[i].len > sizeof(ibuf)) {

				err("i2c rd len=%d too high", msg[i].len);

				break;

			}

		}



		obuf[0] = (msg[i].addr << 1) | (write_read | read);

		if (read)

			obuf[1] = 0;