CVE-2016-5400 (published 2016-08-06T20:59Z)

Memory leak in the airspy_probe function in drivers/media/usb/airspy/airspy.c in the airspy USB driver in the Linux kernel before 4.7 allows local users to cause a denial of service (memory consumption) via a crafted USB device that emulates many VFL_TYPE_SDR or VFL_TYPE_SUBDEV devices and performs many connect and disconnect operations.

Severity: MEDIUM
CVSS v2 base score: 4.9 (AV:L/AC:L/Au:N/C:N/I:N/A:C)
CVSS v3 base score: 4.3, MEDIUM (CVSS:3.0/AV:P/AC:L/PR:L/UI:N/S:U/C:N/I:N/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: James Patrick-Evans
author_date: 2016-07-15 16:40:45+01:00
msg: media: fix airspy usb probe error path

Fix a memory leak on probe error of the airspy usb device driver.

The problem is triggered when more than 64 usb devices register with
v4l2 of type VFL_TYPE_SDR or VFL_TYPE_SUBDEV.

The memory leak is caused by the probe function of the airspy driver
mishandeling errors and not freeing the corresponding control structures
when an error occours registering the device to v4l2 core.

A badusb device can emulate 64 of these devices, and then through
continual emulated connect/disconnect of the 65th device, cause the
kernel to run out of RAM and crash the kernel, thus causing a local DOS
vulnerability.

Fixes CVE-2016-5400

Signed-off-by: James Patrick-Evans <james@jmp-e.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: airspy.c
change_type: ModificationType.MODIFY
diff: @@ -1072,7 +1072,7 @@ static int airspy_probe(struct usb_interface *intf,
 	if (ret) {
 		dev_err(s->dev, "Failed to register as video device (%d)\n",
 				ret);
-		goto err_unregister_v4l2_dev;
+		goto err_free_controls;
 	}
 	dev_info(s->dev, "Registered as %s\n",
 			video_device_node_name(&s->vdev));
@@ -1081,7 +1081,6 @@ static int airspy_probe(struct usb_interface *intf,
 
 err_free_controls:
 	v4l2_ctrl_handler_free(&s->hdl);
-err_unregister_v4l2_dev:
 	v4l2_device_unregister(&s->v4l2_dev);
 err_free_mem:
 	kfree(s);

programming_language: C