CVE-2017-8066 (published 2017-04-23T05:59Z)

drivers/net/can/usb/gs_usb.c in the Linux kernel 4.9.x and 4.10.x before 4.10.2 interacts incorrectly with the CONFIG_VMAP_STACK option, which allows local users to cause a denial of service (system crash or memory corruption) or possibly have unspecified other impact by leveraging use of more than one virtual page for a DMA scatterlist.

Severity: HIGH
CVSS v2 base score: 7.2 (AV:L/AC:L/Au:N/C:C/I:C/A:C)
CVSS v3 base score: 7.8, HIGH (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-119
cwe_name: Improper Restriction of Operations within the Bounds of a Memory Buffer
description: The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
extended_description: 
            Certain languages allow direct addressing of memory locations and do not automatically ensure that these locations are valid for the memory buffer that is being referenced. This can cause read or write operations to be performed on memory locations that may be associated with other variables, data structures, or internal program data.
         
         

Fix information:
repo_url: https://github.com/torvalds/linux
commit_details: repo_url: https://github.com/torvalds/linux
author: Ethan Zonca
author_date: 2017-02-24 11:27:36-05:00
msg: can: gs_usb: Don't use stack memory for USB transfers

Fixes: 05ca5270005c can: gs_usb: add ethtool set_phys_id callback to locate physical device

The gs_usb driver is performing USB transfers using buffers allocated on
the stack. This causes the driver to not function with vmapped stacks.
Instead, allocate memory for the transfer buffers.

Signed-off-by: Ethan Zonca <e@ethanzonca.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v4.8
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
repository: repo_url: https://github.com/torvalds/linux
repo_name: torvalds/linux
description: Linux kernel source tree
repo_language: C
owner: torvalds
file_changes: filename: gs_usb.c
change_type: ModificationType.MODIFY
diff: @@ -908,10 +908,14 @@ static int gs_usb_probe(struct usb_interface *intf,
 	struct gs_usb *dev;
 	int rc = -ENOMEM;
 	unsigned int icount, i;
-	struct gs_host_config hconf = {
-		.byte_order = 0x0000beef,
-	};
-	struct gs_device_config dconf;
+	struct gs_host_config *hconf;
+	struct gs_device_config *dconf;
+
+	hconf = kmalloc(sizeof(*hconf), GFP_KERNEL);
+	if (!hconf)
+		return -ENOMEM;
+
+	hconf->byte_order = 0x0000beef;
 
 	/* send host config */
 	rc = usb_control_msg(interface_to_usbdev(intf),
@@ -920,16 +924,22 @@ static int gs_usb_probe(struct usb_interface *intf,
 			     USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 			     1,
 			     intf->altsetting[0].desc.bInterfaceNumber,
-			     &hconf,
-			     sizeof(hconf),
+			     hconf,
+			     sizeof(*hconf),
 			     1000);
 
+	kfree(hconf);
+
 	if (rc < 0) {
 		dev_err(&intf->dev, "Couldn't send data format (err=%d)\n",
 			rc);
 		return rc;
 	}
 
+	dconf = kmalloc(sizeof(*dconf), GFP_KERNEL);
+	if (!dconf)
+		return -ENOMEM;
+
 	/* read device config */
 	rc = usb_control_msg(interface_to_usbdev(intf),
 			     usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
@@ -937,28 +947,33 @@ static int gs_usb_probe(struct usb_interface *intf,
 			     USB_DIR_IN|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 			     1,
 			     intf->altsetting[0].desc.bInterfaceNumber,
-			     &dconf,
-			     sizeof(dconf),
+			     dconf,
+			     sizeof(*dconf),
 			     1000);
 	if (rc < 0) {
 		dev_err(&intf->dev, "Couldn't get device config: (err=%d)\n",
 			rc);
+		kfree(dconf);
 		return rc;
 	}
 
-	icount = dconf.icount + 1;
+	icount = dconf->icount + 1;
 	dev_info(&intf->dev, "Configuring for %d interfaces\n", icount);
 
 	if (icount > GS_MAX_INTF) {
 		dev_err(&intf->dev,
 			"Driver cannot handle more that %d CAN interfaces\n",
 			GS_MAX_INTF);
+		kfree(dconf);
 		return -EINVAL;
 	}
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (!dev)
+	if (!dev) {
+		kfree(dconf);
 		return -ENOMEM;
+	}
+
 	init_usb_anchor(&dev->rx_submitted);
 
 	atomic_set(&dev->active_channels, 0);
@@ -967,7 +982,7 @@ static int gs_usb_probe(struct usb_interface *intf,
 	dev->udev = interface_to_usbdev(intf);
 
 	for (i = 0; i < icount; i++) {
-		dev->canch[i] = gs_make_candev(i, intf, &dconf);
+		dev->canch[i] = gs_make_candev(i, intf, dconf);
 		if (IS_ERR_OR_NULL(dev->canch[i])) {
 			/* save error code to return later */
 			rc = PTR_ERR(dev->canch[i]);
@@ -978,12 +993,15 @@ static int gs_usb_probe(struct usb_interface *intf,
 				gs_destroy_candev(dev->canch[i]);
 
 			usb_kill_anchored_urbs(&dev->rx_submitted);
+			kfree(dconf);
 			kfree(dev);
 			return rc;
 		}
 		dev->canch[i]->parent = dev;
 	}
 
+	kfree(dconf);
+
 	return 0;
 }
 

programming_language: C