USN-5137-1: Linux kernel vulnerabilities

9 November 2021

Several security issues were fixed in the Linux kernel.

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Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-aws-5.4 - Linux kernel for Amazon Web Services (AWS) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-azure-5.4 - Linux kernel for Microsoft Azure cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-5.4 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke - Linux kernel for Google Container Engine (GKE) systems
  • linux-gkeop - Linux kernel for Google Container Engine (GKE) systems
  • linux-gkeop-5.4 - Linux kernel for Google Container Engine (GKE) systems
  • linux-hwe-5.4 - Linux hardware enablement (HWE) kernel
  • linux-ibm - Linux kernel for IBM cloud systems
  • linux-kvm - Linux kernel for cloud environments

Details

It was discovered that the f2fs file system in the Linux kernel did not
properly validate metadata in some situations. An attacker could use this
to construct a malicious f2fs image that, when mounted and operated on,
could cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2019-19449)

It was discovered that the Infiniband RDMA userspace connection manager
implementation in the Linux kernel contained a race condition leading to a
use-after-free vulnerability. A local attacker could use this to cause a
denial of service (system crash) or possible execute arbitrary code.
(CVE-2020-36385)

Wolfgang Frisch discovered that the ext4 file system implementation in the
Linux kernel contained an integer overflow when handling metadata inode
extents. An attacker could use this to construct a malicious ext4 file
system image that, when mounted, could cause a denial of service (system
crash). (CVE-2021-3428)

Benedict Schlueter discovered that the BPF subsystem in the Linux kernel
did not properly protect against Speculative Store Bypass (SSB) side-
channel attacks in some situations. A local attacker could possibly use
this to expose sensitive information. (CVE-2021-34556)

Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not
properly protect against Speculative Store Bypass (SSB) side-channel
attacks in some situations. A local attacker could possibly use this to
expose sensitive information. (CVE-2021-35477)

It was discovered that the btrfs file system in the Linux kernel did not
properly handle removing a non-existent device id. An attacker with
CAP_SYS_ADMIN could use this to cause a denial of service. (CVE-2021-3739)

It was discovered that the Qualcomm IPC Router protocol implementation in
the Linux kernel did not properly validate metadata in some situations. A
local attacker could use this to cause a denial of service (system crash)
or expose sensitive information. (CVE-2021-3743)

It was discovered that the virtual terminal (vt) device implementation in
the Linux kernel contained a race condition in its ioctl handling that led
to an out-of-bounds read vulnerability. A local attacker could possibly use
this to expose sensitive information. (CVE-2021-3753)

It was discovered that the Linux kernel did not properly account for the
memory usage of certain IPC objects. A local attacker could use this to
cause a denial of service (memory exhaustion). (CVE-2021-3759)

It was discovered that the Aspeed Low Pin Count (LPC) Bus Controller
implementation in the Linux kernel did not properly perform boundary checks
in some situations, allowing out-of-bounds write access. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. In Ubuntu, this issue only affected systems running
armhf kernels. (CVE-2021-42252)

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Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 20.04
Ubuntu 18.04

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.

References

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