Use After Free Affecting kernel-rt-devel package, versions <0:3.10.0-1160.118.1.rt56.1269.el7


Severity

Recommended
0.0
high
0
10

Based on CentOS security rating

    Threat Intelligence

    EPSS
    0.04% (6th percentile)

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  • Snyk ID SNYK-CENTOS7-KERNELRTDEVEL-5890432
  • published 7 Sep 2023
  • disclosed 6 Sep 2023

How to fix?

Upgrade Centos:7 kernel-rt-devel to version 0:3.10.0-1160.118.1.rt56.1269.el7 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-devel package and not the kernel-rt-devel package as distributed by Centos. See How to fix? for Centos:7 relevant fixed versions and status.

A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.

If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.

We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.

CVSS Scores

version 3.1
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NVD

7.8 high
  • Attack Vector (AV)
    Local
  • Attack Complexity (AC)
    Low
  • Privileges Required (PR)
    Low
  • User Interaction (UI)
    None
  • Scope (S)
    Unchanged
  • Confidentiality (C)
    High
  • Integrity (I)
    High
  • Availability (A)
    High
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Red Hat

7.8 high
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SUSE

7.8 high