From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alyssa Milburn , Mauro Carvalho Chehab Subject: [PATCH 4.4 058/103] [media] ttusb2: limit messages to buffer size Date: Tue, 23 May 2017 22:09:24 +0200 Message-Id: <20170523200901.523568677@linuxfoundation.org> In-Reply-To: <20170523200856.903752266@linuxfoundation.org> References: <20170523200856.903752266@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alyssa Milburn commit a12b8ab8c5ff7ccd7b107a564743507c850a441d upstream. Otherwise ttusb2_i2c_xfer can read or write beyond the end of static and heap buffers. Signed-off-by: Alyssa Milburn Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/dvb-usb/ttusb2.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) --- a/drivers/media/usb/dvb-usb/ttusb2.c +++ b/drivers/media/usb/dvb-usb/ttusb2.c @@ -78,6 +78,9 @@ static int ttusb2_msg(struct dvb_usb_dev 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_ad 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;