USN-6338-2: Linux kernel vulnerabilities

8 September 2023

Several security issues were fixed in the Linux kernel.

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Releases

Packages

  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-6.2 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-ibm - Linux kernel for IBM cloud systems
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-starfive - Linux kernel for StarFive processors

Details

Zi Fan Tan discovered that the binder IPC implementation in the Linux
kernel contained 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-2023-21255)

It was discovered that a race condition existed in the f2fs file system in
the Linux kernel, leading to a null pointer dereference vulnerability. 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).
(CVE-2023-2898)

It was discovered that the DVB Core driver in the Linux kernel did not
properly handle locking events in certain situations. A local attacker
could use this to cause a denial of service (kernel deadlock).
(CVE-2023-31084)

Quentin Minster discovered that the KSMBD implementation in the Linux
kernel did not properly handle session setup requests. A remote attacker
could possibly use this to cause a denial of service (memory exhaustion).
(CVE-2023-32247)

Quentin Minster discovered that a race condition existed in the KSMBD
implementation in the Linux kernel when handling sessions operations. A
remote attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code. (CVE-2023-32250, CVE-2023-32252,
CVE-2023-32257)

It was discovered that a race condition existed in the KSMBD implementation
in the Linux kernel when handling session connections, leading to a use-
after-free vulnerability. A remote attacker could use this to cause a
denial of service (system crash) or possibly execute arbitrary code.
(CVE-2023-32258)

It was discovered that the KSMBD implementation in the Linux kernel did not
properly validate buffer sizes in certain operations, leading to an out-of-
bounds read vulnerability. A remote attacker could use this to cause a
denial of service (system crash) or possibly expose sensitive information.
(CVE-2023-38426, CVE-2023-38428)

It was discovered that the KSMBD implementation in the Linux kernel did not
properly calculate the size of certain buffers. A remote attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2023-38429)

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Update instructions

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

Ubuntu 23.04
Ubuntu 22.04

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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