CVE-2021-47231 Affecting kernel-preempt package, versions <5.3.18-150300.59.164.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.04% (12th percentile)

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  • Snyk IDSNYK-SLES153-KERNELPREEMPT-7363040
  • published25 Jun 2024
  • disclosed24 Jun 2024

Introduced: 24 Jun 2024

CVE-2021-47231  (opens in a new tab)

How to fix?

Upgrade SLES:15.3 kernel-preempt to version 5.3.18-150300.59.164.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-preempt package and not the kernel-preempt package as distributed by SLES. See How to fix? for SLES:15.3 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

can: mcba_usb: fix memory leak in mcba_usb

Syzbot reported memory leak in SocketCAN driver for Microchip CAN BUS Analyzer Tool. The problem was in unfreed usb_coherent.

In mcba_usb_start() 20 coherent buffers are allocated and there is nothing, that frees them:

  1. In callback function the urb is resubmitted and that's all
  2. In disconnect function urbs are simply killed, but URB_FREE_BUFFER is not set (see mcba_usb_start) and this flag cannot be used with coherent buffers.

Fail log: | [ 1354.053291][ T8413] mcba_usb 1-1:0.0 can0: device disconnected | [ 1367.059384][ T8420] kmemleak: 20 new suspected memory leaks (see /sys/kernel/debug/kmem)

So, all allocated buffers should be freed with usb_free_coherent() explicitly

NOTE: The same pattern for allocating and freeing coherent buffers is used in drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c

CVSS Scores

version 3.1