diff mbox series

[v3] USB: hso: Fix OOB memory access in hso_probe/hso_get_config_data

Message ID 20181212114224.GB26559@kroah.com (mailing list archive)
State Accepted
Commit 5146f95df782b0ac61abde36567e718692725c89
Headers show
Series [v3] USB: hso: Fix OOB memory access in hso_probe/hso_get_config_data | expand

Commit Message

Greg KH Dec. 12, 2018, 11:42 a.m. UTC 
From: Hui Peng <benquike@gmail.com>

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 <benquike@gmail.com>
Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
Signed-off-by: Hui Peng <benquike@gmail.com>
Signed-off-by: Mathias Payer <mathias.payer@nebelwelt.net>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

v3: redid the changelog text based on review comments from Sebastian

v2: fixed error check to just be < 0
    Added CVE to changelog text

 drivers/net/usb/hso.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

Comments

David Miller Dec. 12, 2018, 11:41 p.m. UTC | #1 
From: Greg KH <gregkh@linuxfoundation.org>
Date: Wed, 12 Dec 2018 12:42:24 +0100

> From: Hui Peng <benquike@gmail.com>
> 
> 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 <benquike@gmail.com>
> Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
> Signed-off-by: Hui Peng <benquike@gmail.com>
> Signed-off-by: Mathias Payer <mathias.payer@nebelwelt.net>
> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Applied and queued up for -stable, thanks Greg.
diff mbox series

Patch

diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 184c24baca15..d6916f787fce 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -2807,6 +2807,12 @@  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;
@@ -2877,10 +2883,18 @@  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 */