From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.14 21/59] USB: hso: Fix OOB memory access in hso_probe/hso_get_config_data Date: Wed, 26 Dec 2018 17:38:01 -0500 Message-ID: <20181226223839.150262-21-sashal@kernel.org> References: <20181226223839.150262-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Hui Peng , Mathias Payer , Greg Kroah-Hartman , "David S . Miller" , Sasha Levin , linux-usb@vger.kernel.org, netdev@vger.kernel.org To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: In-Reply-To: <20181226223839.150262-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Hui Peng [ Upstream commit 5146f95df782b0ac61abde36567e718692725c89 ] The function hso_probe reads if_num from the USB device (as an u8) and uses it without a length check to index an array, resulting in an OOB memory read in hso_probe or hso_get_config_data. Add a length check for both locations and updated hso_probe to bail on error. This issue has been assigned CVE-2018-19985. Reported-by: Hui Peng Reported-by: Mathias Payer Signed-off-by: Hui Peng Signed-off-by: Mathias Payer Reviewed-by: Sebastian Andrzej Siewior Signed-off-by: Greg Kroah-Hartman Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/usb/hso.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index d7a3379ea668..18a0952f68a8 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -2806,6 +2806,12 @@ static int hso_get_config_data(struct usb_interface *interface) return -EIO; } + /* check if we have a valid interface */ + if (if_num > 16) { + kfree(config_data); + return -EINVAL; + } + switch (config_data[if_num]) { case 0x0: result = 0; @@ -2876,10 +2882,18 @@ static int hso_probe(struct usb_interface *interface, /* Get the interface/port specification from either driver_info or from * the device itself */ - if (id->driver_info) + if (id->driver_info) { + /* if_num is controlled by the device, driver_info is a 0 terminated + * array. Make sure, the access is in bounds! */ + for (i = 0; i <= if_num; ++i) + if (((u32 *)(id->driver_info))[i] == 0) + goto exit; port_spec = ((u32 *)(id->driver_info))[if_num]; - else + } else { port_spec = hso_get_config_data(interface); + if (port_spec < 0) + goto exit; + } /* Check if we need to switch to alt interfaces prior to port * configuration */ -- 2.19.1