RHSA-2021:0878HighCVSS 7.8

Red Hat Security Advisory: kernel security, bug fix, and enhancement update

Published
March 16, 2021
Last Modified
November 5, 2026

🔗 CVE IDs covered (4)

CVE-2020-25212 →CVE-2020-29661 →CVE-2020-14351 →CVE-2020-24394 →

📋 Description

CVE-2020-14351 — kernel: performance counters race condition use-after-free CVE-2020-24394 — kernel: umask not applied on filesystem without ACL support CVE-2020-25212 — kernel: TOCTOU mismatch in the NFS client code CVE-2020-29661 — kernel: locking issue in drivers/tty/tty_jobctrl.c can lead to an use-after-free

🎯 Affected products116

  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.6)
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6)
  • Red Hat Enterprise Linux Server EUS (v. 7.6)
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.6)
  • Red Hat Virtualization 4.2 Hypervisor for RHEL 7.6 EUS
  • bpftool-0:3.10.0-957.70.1.el7.x86_64 as a component of Red Hat Enterprise Linux ComputeNode EUS (v. 7.6)
  • bpftool-0:3.10.0-957.70.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-0:3.10.0-957.70.1.el7.ppc64 as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-0:3.10.0-957.70.1.el7.ppc64le as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-0:3.10.0-957.70.1.el7.s390x as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-0:3.10.0-957.70.1.el7.src as a component of Red Hat Enterprise Linux ComputeNode EUS (v. 7.6)
  • kernel-0:3.10.0-957.70.1.el7.src as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-0:3.10.0-957.70.1.el7.x86_64 as a component of Red Hat Enterprise Linux ComputeNode EUS (v. 7.6)
  • kernel-0:3.10.0-957.70.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-abi-whitelists-0:3.10.0-957.70.1.el7.noarch as a component of Red Hat Enterprise Linux ComputeNode EUS (v. 7.6)
  • kernel-abi-whitelists-0:3.10.0-957.70.1.el7.noarch as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-bootwrapper-0:3.10.0-957.70.1.el7.ppc64 as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-bootwrapper-0:3.10.0-957.70.1.el7.ppc64le as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-debug-0:3.10.0-957.70.1.el7.ppc64 as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-debug-0:3.10.0-957.70.1.el7.ppc64le as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-debug-0:3.10.0-957.70.1.el7.s390x as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-debug-0:3.10.0-957.70.1.el7.x86_64 as a component of Red Hat Enterprise Linux ComputeNode EUS (v. 7.6)
  • kernel-debug-0:3.10.0-957.70.1.el7.x86_64 as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.70.1.el7.ppc64 as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.70.1.el7.ppc64 as a component of Red Hat Enterprise Linux Server Optional EUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.70.1.el7.ppc64le as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.70.1.el7.ppc64le as a component of Red Hat Enterprise Linux Server Optional EUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.70.1.el7.s390x as a component of Red Hat Enterprise Linux Server EUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.70.1.el7.x86_64 as a component of Red Hat Enterprise Linux ComputeNode EUS (v. 7.6)
  • kernel-debug-debuginfo-0:3.10.0-957.70.1.el7.x86_64 as a component of Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6)
  • +86 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Workaround: While there is no way to disable the perf subsystem on Linux systems, reducing or removing users access to the perf events can effectively mitigate this flaw. Upstream kernel documentation has been written regarding this mechanism: https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html. Workaround: Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. Workaround: While there is no known mitigation to this flaw, configuring authentication and only mounting authenticated NFSv4 servers will significantly reduce the risk of this flaw being successfully exploited. Workaround: Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.

🔗 References (7)