LSN-0076-1: Kernel Live Patch Security Notice

Publication date

3 May 2021

Overview

Several security issues were fixed in the kernel.


Software description

  • aws – Linux kernel for Amazon Web Services (AWS) systems - (>= 4.15.0-1054, >= 5.4.0-1009, >= 4.4.0-1098)
  • azure – Linux kernel for Microsoft Azure Cloud systems - (>= 5.4.0-1010, >= 4.15.0-1063, >= 4.15.0-1078)
  • gcp – Linux kernel for Google Cloud Platform (GCP) systems - (>= 5.4.0-1009)
  • generic-4.15 – Linux hardware enablement (HWE) kernel - (>= 4.15.0-69, >= 4.15.0-69)
  • generic-4.4 – Linux kernel - (>= 4.4.0-168, >= 4.4.0-168)
  • generic-5.4 – Linux kernel - (>= 5.4.0-26, >= 5.4.0-26)
  • gke – Linux kernel for Google Container Engine (GKE) systems - (>= 5.4.0-1033)
  • gke-4.15 – Linux kernel for Google Container Engine (GKE) systems - (>= 4.15.0-1076)
  • gke-5.4 – Linux kernel for Google Container Engine (GKE) systems - (>= 5.4.0-1009)
  • gkeop – Linux kernel for Google Container Engine (GKE) systems - (>= 5.4.0-1009)
  • gkeop-5.4 – Linux kernel for Google Container Engine (GKE) systems - (>= 5.4.0-1007)
  • lowlatency-4.15 – Linux hardware enablement (HWE) kernel - (>= 4.15.0-69, >= 4.15.0-69)
  • lowlatency-4.4 – Linux kernel - (>= 4.4.0-168, >= 4.4.0-168)
  • aws – Linux kernel for Amazon Web Services (AWS) systems - (>= 4.15.0-1054, >= 5.4.0-1009, >= 4.4.0-1098)
  • azure – Linux kernel for Microsoft Azure Cloud systems - (>= 5.4.0-1010, >= 4.15.0-1063, >= 4.15.0-1078)
  • gcp – Linux kernel for Google Cloud Platform (GCP) systems - (>= 5.4.0-1009)
  • generic-4.15 – Linux hardware enablement (HWE) kernel - (>= 4.15.0-69, >= 4.15.0-69)
  • generic-4.4 – Linux kernel - (>= 4.4.0-168, >= 4.4.0-168)
  • generic-5.4 – Linux kernel - (>= 5.4.0-26, >= 5.4.0-26)
  • gke – Linux kernel for Google Container Engine (GKE) systems - (>= 5.4.0-1033)
  • gke-4.15 – Linux kernel for Google Container Engine (GKE) systems - (>= 4.15.0-1076)
  • gke-5.4 – Linux kernel for Google Container Engine (GKE) systems - (>= 5.4.0-1009)
  • gkeop – Linux kernel for Google Container Engine (GKE) systems - (>= 5.4.0-1009)
  • gkeop-5.4 – Linux kernel for Google Container Engine (GKE) systems - (>= 5.4.0-1007)
  • lowlatency-4.15 – Linux hardware enablement (HWE) kernel - (>= 4.15.0-69, >= 4.15.0-69)
  • lowlatency-4.4 – Linux kernel - (>= 4.4.0-168, >= 4.4.0-168)
  • lowlatency-5.4 – Linux kernel - (>= 5.4.0-26, >= 5.4.0-26)
  • oem – Linux kernel for OEM systems - (>= 4.15.0-1063)

Details

It was discovered that the overlayfs implementation in the Linux kernel did
not properly validate the application of file system capabilities with
respect to user namespaces. A local attacker could use this to gain
elevated privileges.(CVE-2021-3493)

Piotr Krysiuk discovered that the BPF JIT compiler for x86 in the Linux
kernel did not properly validate computation of branch displacements in
some situations. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code.(CVE-2021-29154)

It was discovered that the overlayfs implementation in the Linux kernel did
not properly validate the application of file system capabilities with
respect to user namespaces. A local attacker could use this to gain
elevated privileges.(CVE-2021-3493)

Piotr Krysiuk discovered that the BPF JIT compiler for x86 in the Linux
kernel did not properly validate computation of branch displacements in
some situations. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code.(CVE-2021-29154)

Checking update status

To check your kernel type and Livepatch version, enter this command:

canonical-livepatch status

The problem can be corrected in these Livepatch versions:

Kernel type 20.04 18.04 16.04 14.04
aws 76.3 76.2 76.1 —
azure 76.3 — 76.2 —
gcp 76.3 — — —
generic-4.15 — 76.2 76.2 —
generic-4.4 — — 76.1 76.1
generic-5.4 76.3 76.3 — —
gke 76.3 — — —
gke-4.15 — 76.1 — —
gke-5.4 — 76.3 — —
gkeop 76.3 — — —
gkeop-5.4 — 76.3 — —
lowlatency-4.15 — 76.2 76.2 —
lowlatency-4.4 — — 76.1 76.1
lowlatency-5.4 76.3 76.3 — —
oem — 76.2 — —

References


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