LSN-0076-1: Kernel Live Patch Security Notice
3 May 2021
Several security issues were fixed in the kernel.
Releases
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)
- 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)
Checking update 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 | — | — |
To check your kernel type and Livepatch version, enter this command:
canonical-livepatch status