LSN-0082-1: Kernel Live Patch Security Notice
11 November 2021
Several security issues were fixed in the kernel.
Releases
Software Description
- 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, >= 4.15.0-143, >= 4.15.0-69)
- generic-4.4 - Linux kernel - (>= 4.4.0-211, >= 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, >= 4.15.0-143, >= 4.15.0-69)
- lowlatency-4.4 - Linux kernel - (>= 4.4.0-211, >= 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
Jann Horn discovered that the tty subsystem of the Linux kernel did not use
consistent locking in some situations, leading to a read-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly expose sensitive information (kernel memory).(CVE-2020-29660)
Jann Horn discovered a race condition in the tty subsystem of the Linux
kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after-
free vulnerability. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code.(CVE-2020-29661)
De4dCr0w of 360 Alpha Lab discovered that the BPF verifier in the Linux
kernel did not properly handle mod32 destination register truncation when
the source register was known to be 0. A local attacker could use this to
expose sensitive information (kernel memory) or possibly execute arbitrary
code.(CVE-2021-3444)
kernel: use-after-free in route4_change() in
net/sched/cls_route.c(CVE-2021-3715)
Checking update status
The problem can be corrected in these Livepatch versions:
| Kernel type | 20.04 | 18.04 | 16.04 |
|---|---|---|---|
| gcp | 82.2 | — | — |
| generic-4.15 | — | 82.2 | 82.2 |
| generic-4.4 | — | — | 82.2 |
| generic-5.4 | 82.2 | 82.2 | — |
| gke | 82.2 | — | — |
| gke-4.15 | — | 82.2 | — |
| gke-5.4 | — | 82.2 | — |
| gkeop | 82.2 | — | — |
| gkeop-5.4 | — | 82.2 | — |
| lowlatency-4.15 | — | 82.2 | 82.2 |
| lowlatency-4.4 | — | — | 82.2 |
| lowlatency-5.4 | 82.2 | 82.2 | — |
| oem | — | 82.2 | — |
To check your kernel type and Livepatch version, enter this command:
canonical-livepatch status