Ubuntu Security Notices
USN-8597-1

USN-8597-1: Linux kernel (IBM) vulnerabilities

Publication date

23 July 2026

Overview

Several security issues were fixed in the Linux kernel.

Releases

20.04 LTS

Packages

linux-ibm-5.15 - Linux kernel for IBM cloud systems

Details

Maxim Suhanov discovered that the NTFS file system implementation in the
Linux kernel did not properly validate file name length in certain
situations, leading to an out-of-bounds read. An attacker could use this to
construct a malicious NTFS image that, when mounted and operated on, could
expose sensitive information (kernel memory). (CVE-2023-45896)

It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)

It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (

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;
S390 architecture;
x86 architecture;
Cryptographic API;
ACPI drivers;
ATM drivers;
Power management core;
DRBD Distributed Replicated Block Device drivers;
RNBD block device driver;
Bluetooth drivers;
Character device driver;
TPM device driver;
Clocksource drivers;
Data acquisition framework and drivers;
CPU idle management framework;
Hardware crypto device drivers;
DMA engine subsystem;
EFI core;
GPIO subsystem;
GPU drivers;
HID subsystem;
Hardware monitoring drivers;
I2C subsystem;
IIO ADC drivers;
IIO subsystem;
InfiniBand drivers;
IOMMU subsystem;
Mailbox framework;
Multiple devices driver;
Media drivers;
MediaTek SMI driver;
IBM Advanced System Management driver;
MMC subsystem;
MTD block device drivers;
Network drivers;
Ethernet bonding driver;
Mellanox network drivers;
Microsoft Azure Network Adapter (MANA) driver;
STMicroelectronics network drivers;
Near Field Communication (NFC) drivers;
NTB driver;
NVME drivers;
PCI subsystem;
x86 platform drivers;
Broadcom BCM2835 power domain driver;
Power supply drivers;
RapidIO drivers;
Remote Processor subsystem;
RPMSG subsystem;
SCSI subsystem;
Freescale SoC drivers;
Texas Instruments SoC drivers;
SPI subsystem;
Greybus lights staging drivers;
Media staging drivers;
Realtek RTL8723BS SDIO drivers;
SM750 framebuffer staging driver;
TCM subsystem;
TTY drivers;
UFS subsystem;
Cadence USB3 driver;
USB Device Class drivers;
ULPI bus;
USB core drivers;
DesignWare USB2 driver;
USB Gadget drivers;
USB Host Controller drivers;
Mustek MDC800 USB digital camera driver;
USB YUREX driver;
Framebuffer layer;
File systems infrastructure;
BTRFS file system;
Ceph distributed file system;
EROFS file system;
Ext4 file system;
F2FS file system;
FAT file system;
FUSE (File system in Userspace);
GFS2 file system;
HFS+ file system;
JFS file system;
Network file system (NFS) server daemon;
NILFS2 file system;
File system notification infrastructure;
NTFS3 file system;
OCFS2 file system;
Proc file system;
Pstore file system;
SMB network file system;
SquashFS file system;
XFS file system;
Audit subsystem;
RAS (Reliability, Availability, Serviceability) subsystem;
CPU frequency scaling framework;
Memory Management;
KVM subsystem;
Memory management;
Network traffic control;
Netfilter;
IP tunnels definitions;
Tracing infrastructure;
User-space API (UAPI);
io_uring subsystem;
BPF subsystem;
Control group (cgroup);
Kernel fork() syscall;
Kernel futex primitives;
Kernel kexec() syscall;
Kernel module support;
Scheduler infrastructure;
Cryptographic library;
Asynchronous Transfer Mode (ATM) subsystem;
B.A.T.M.A.N. meshing protocol;
Bluetooth subsystem;
Ethernet bridge;
CAIF protocol;
CAN network layer;
Ceph Core library;
Networking core;
IPv4 networking;
IPv6 networking;
XFRM subsystem;
L2TP protocol;
MAC80211 subsystem;
Management Component Transport Protocol (MCTP);
Multipath TCP;
NCSI (Network Controller Sideband Interface) driver;
NFC subsystem;
Open vSwitch;
Qualcomm IPC Router (QRTR);
RDS protocol;
RF switch subsystem;
Rose network layer;
RxRPC session sockets;
SCTP protocol;
SMC sockets;
Stream parser;
Sun RPC protocol;
TIPC protocol;
Unix domain sockets;
VMware vSockets driver;
Wireless networking;
X.25 network layer;
eXpress Data Path;
AppArmor security module;
ALSA framework;
FireWire sound drivers;
Creative Sound Blaster X-Fi driver;
SoC audio core drivers;
USB sound devices

Update instructions

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

Learn more about how to get the fixes.

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.

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

Ubuntu Release	Package Version
20.04 LTS focal	linux-image-5.15.0-1106-ibm – 5.15.0-1106.110~20.04.1
	linux-image-ibm – 5.15.0.1106.110~20.04.1
	linux-image-ibm-5.15 – 5.15.0.1106.110~20.04.1