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Ubuntu Security Notice USN-7940-1 reports multiple security vulnerabilities fixed in the Linux kernel for Ubuntu 24.04 LTS. The vulnerabilities, including CVE-2025-40300 (VMSCAPE), allow an attacker to potentially expose sensitive information or compromise the system. To fix these issues, users need to update their system to the latest package versions and reboot their computer after a standard system update. Additionally, due to an ABI change, users may need to recompile and reinstall third-party kernel modules they have installed.

[USN-7940-1] Linux kernel (Azure FIPS) vulnerabilities




[USN-7940-1] Linux kernel (Azure FIPS) vulnerabilities


==========================================================================
Ubuntu Security Notice USN-7940-1
December 17, 2025

linux-azure-fips vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 24.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-azure-fips: Linux kernel for Microsoft Azure Cloud systems with FIPS

Details:

Jean-Claude Graf, Sandro Rüegge, Ali Hajiabadi, and Kaveh Razavi discovered
that the Linux kernel contained insufficient branch predictor isolation
between a guest and a userspace hypervisor for certain processors. This
flaw is known as VMSCAPE. An attacker in a guest VM could possibly use this
to expose sensitive information from the host OS. (CVE-2025-40300)

Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- PowerPC architecture;
- x86 architecture;
- Cryptographic API;
- ACPI drivers;
- Ublk userspace block driver;
- Clock framework and drivers;
- EDAC drivers;
- GPU drivers;
- HSI subsystem;
- IIO subsystem;
- InfiniBand drivers;
- Media drivers;
- MemoryStick subsystem;
- Network drivers;
- NTB driver;
- PCI subsystem;
- Remote Processor subsystem;
- Thermal drivers;
- Virtio Host (VHOST) subsystem;
- 9P distributed file system;
- File systems infrastructure;
- JFS file system;
- Network file system (NFS) server daemon;
- NTFS3 file system;
- SMB network file system;
- Memory management;
- Bluetooth subsystem;
- RDMA verbs API;
- Kernel fork() syscall;
- Timer subsystem;
- Tracing infrastructure;
- Watch queue notification mechanism;
- Appletalk network protocol;
- Asynchronous Transfer Mode (ATM) subsystem;
- Networking core;
- IPv4 networking;
- IPv6 networking;
- Netfilter;
- Network traffic control;
- SCTP protocol;
- TLS protocol;
- SoC Audio for Freescale CPUs drivers;
(CVE-2023-53034, CVE-2024-58092, CVE-2025-21729, CVE-2025-22018,
CVE-2025-22019, CVE-2025-22020, CVE-2025-22021, CVE-2025-22025,
CVE-2025-22027, CVE-2025-22028, CVE-2025-22033, CVE-2025-22035,
CVE-2025-22036, CVE-2025-22038, CVE-2025-22039, CVE-2025-22040,
CVE-2025-22041, CVE-2025-22042, CVE-2025-22044, CVE-2025-22045,
CVE-2025-22047, CVE-2025-22050, CVE-2025-22053, CVE-2025-22054,
CVE-2025-22055, CVE-2025-22056, CVE-2025-22057, CVE-2025-22058,
CVE-2025-22060, CVE-2025-22062, CVE-2025-22063, CVE-2025-22064,
CVE-2025-22065, CVE-2025-22066, CVE-2025-22068, CVE-2025-22070,
CVE-2025-22071, CVE-2025-22072, CVE-2025-22073, CVE-2025-22075,
CVE-2025-22079, CVE-2025-22080, CVE-2025-22081, CVE-2025-22083,
CVE-2025-22086, CVE-2025-22089, CVE-2025-22090, CVE-2025-22095,
CVE-2025-22097, CVE-2025-23136, CVE-2025-23138, CVE-2025-37838,
CVE-2025-37937, CVE-2025-37958, CVE-2025-38118, CVE-2025-38152,
CVE-2025-38227, CVE-2025-38240, CVE-2025-38352, CVE-2025-38575,
CVE-2025-38616, CVE-2025-38637, CVE-2025-38666, CVE-2025-38678,
CVE-2025-39682, CVE-2025-39728, CVE-2025-39735, CVE-2025-39964,
CVE-2025-39993, CVE-2025-40018, CVE-2025-40114, CVE-2025-40157)

Update instructions:

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

Ubuntu 24.04 LTS
linux-image-6.8.0-1044-azure-fips 6.8.0-1044.50+fips1
Available with Ubuntu Pro
linux-image-azure-fips 6.8.0-1044.50+fips1
Available with Ubuntu Pro
linux-image-azure-fips-6.8 6.8.0-1044.50+fips1
Available with Ubuntu Pro

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:
https://ubuntu.com/security/notices/USN-7940-1
CVE-2023-53034, CVE-2024-58092, CVE-2025-21729, CVE-2025-22018,
CVE-2025-22019, CVE-2025-22020, CVE-2025-22021, CVE-2025-22025,
CVE-2025-22027, CVE-2025-22028, CVE-2025-22033, CVE-2025-22035,
CVE-2025-22036, CVE-2025-22038, CVE-2025-22039, CVE-2025-22040,
CVE-2025-22041, CVE-2025-22042, CVE-2025-22044, CVE-2025-22045,
CVE-2025-22047, CVE-2025-22050, CVE-2025-22053, CVE-2025-22054,
CVE-2025-22055, CVE-2025-22056, CVE-2025-22057, CVE-2025-22058,
CVE-2025-22060, CVE-2025-22062, CVE-2025-22063, CVE-2025-22064,
CVE-2025-22065, CVE-2025-22066, CVE-2025-22068, CVE-2025-22070,
CVE-2025-22071, CVE-2025-22072, CVE-2025-22073, CVE-2025-22075,
CVE-2025-22079, CVE-2025-22080, CVE-2025-22081, CVE-2025-22083,
CVE-2025-22086, CVE-2025-22089, CVE-2025-22090, CVE-2025-22095,
CVE-2025-22097, CVE-2025-23136, CVE-2025-23138, CVE-2025-37838,
CVE-2025-37937, CVE-2025-37958, CVE-2025-38118, CVE-2025-38152,
CVE-2025-38227, CVE-2025-38240, CVE-2025-38352, CVE-2025-38575,
CVE-2025-38616, CVE-2025-38637, CVE-2025-38666, CVE-2025-38678,
CVE-2025-39682, CVE-2025-39728, CVE-2025-39735, CVE-2025-39964,
CVE-2025-39993, CVE-2025-40018, CVE-2025-40114, CVE-2025-40157,
CVE-2025-40300

Package Information:
https://launchpad.net/ubuntu/+source/linux-azure-fips/6.8.0-1044.50+fips1