USN-4984-1: Linux kernel vulnerabilities

8 June 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-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-hwe-5.8 - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-raspi - Linux kernel for Raspberry Pi (V8) systems

Details

Jan Beulich discovered that the Xen netback backend in the Linux kernel did
not properly handle certain error conditions under paravirtualization. An
attacker in a guest VM could possibly use this to cause a denial of service
(host domain crash). (CVE-2021-28038)

It was discovered that the Realtek RTL8188EU Wireless device driver in the
Linux kernel did not properly validate ssid lengths in some situations. An
attacker could use this to cause a denial of service (system crash).
(CVE-2021-28660)

It was discovered that the Xen paravirtualization backend in the Linux
kernel did not properly deallocate memory in some situations. A local
attacker could use this to cause a denial of service (memory exhaustion).
(CVE-2021-28688)

It was discovered that the fuse user space file system implementation in
the Linux kernel did not properly handle bad inodes in some situations. A
local attacker could possibly use this to cause a denial of service.
(CVE-2021-28950)

John Stultz discovered that the audio driver for Qualcomm SDM845 systems in
the Linux kernel did not properly validate port ID numbers. A local
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2021-28952)

Zygo Blaxell discovered that the btrfs file system implementation in the
Linux kernel contained a race condition during certain cloning operations.
A local attacker could possibly use this to cause a denial of service
(system crash). (CVE-2021-28964)

Vince Weaver discovered that the perf subsystem in the Linux kernel did not
properly handle certain PEBS records properly for some Intel Haswell
processors. A local attacker could use this to cause a denial of service
(system crash). (CVE-2021-28971)

It was discovered that the RPA PCI Hotplug driver implementation in the
Linux kernel did not properly handle device name writes via sysfs, leading
to a buffer overflow. A privileged attacker could use this to cause a
denial of service (system crash) or possibly execute arbitrary code.
(CVE-2021-28972)

It was discovered that the Qualcomm IPC router implementation in the Linux
kernel did not properly initialize memory passed to user space. A local
attacker could use this to expose sensitive information (kernel memory).
(CVE-2021-29647)

Arnd Bergmann discovered that the video4linux subsystem in the Linux kernel
did not properly deallocate memory in some situations. A local attacker
could use this to cause a denial of service (memory exhaustion).
(CVE-2021-30002)

Dan Carpenter discovered that the block device manager (dm) implementation
in the Linux kernel contained a buffer overflow in the ioctl for listing
devices. A privileged local attacker could use this to cause a denial of
service (system crash). (CVE-2021-31916)

It was discovered that the CIPSO implementation in the Linux kernel did not
properly perform reference counting in some situations, leading to use-
after-free vulnerabilities. An attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2021-33033)

马哲宇 discovered that the IEEE 1394 (Firewire) nosy packet sniffer driver in
the Linux kernel did not properly perform reference counting in some
situations, 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-2021-3483)

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Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

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Update instructions

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

Ubuntu 20.10
Ubuntu 20.04

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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