CVE-2024-26989 is a vulnerability identified in the Linux kernel specifically affecting the arm64 architecture's hibernation functionality. The flaw resides in the swsusp_save() function, which is responsible for saving system state during hibernation. On arm64 machines, swsusp_save() can trigger a level 3 translation fault when it attempts to access MEMBLOCK_NOMAP memory regions—areas of memory that should not be mapped or saved during hibernation. This fault manifests as a kernel paging request error, causing an internal kernel error (Oops) and potentially leading to system crashes or instability during suspend or hibernation operations. The root cause is a logic error introduced by a prior kernel commit (a7d9f306ba70) that altered the pfn_valid() function, causing kernel_page_present() to incorrectly assume certain pages are always present even when they fall within MEMBLOCK_NOMAP ranges. This results in swsusp_save() attempting to save memory pages that should be excluded, leading to faults. The issue can be reproduced in QEMU environments with specific boot parameters disabling read-only data and debug page allocation, indicating it affects certain kernel configurations. The fix involves adjusting kernel_page_present() to properly exclude MEMBLOCK_NOMAP pages during hibernation save operations, aligning arm64 behavior with other architectures. While this vulnerability does not have a CVSS score assigned yet, it is a kernel-level fault that can cause system crashes during suspend/resume cycles on affected arm64 Linux systems. There are no known exploits in the wild at this time.

For European organizations utilizing arm64-based Linux systems—such as servers, embedded devices, or specialized hardware—this vulnerability poses a risk of system instability or crashes during hibernation or suspend operations. This can lead to unexpected downtime, data loss, or disruption of critical services relying on these systems. Organizations employing Linux in ARM64 environments for cloud infrastructure, edge computing, or IoT deployments may experience increased operational risk. Although the vulnerability does not directly enable privilege escalation or remote code execution, the denial-of-service impact through kernel panics can affect availability and reliability of services. In sectors such as telecommunications, manufacturing, or public services where ARM64 Linux devices are deployed, this could translate into operational interruptions. The absence of known exploits reduces immediate threat but does not eliminate risk, especially as attackers may develop exploits targeting this kernel fault. Additionally, debugging and recovery from such kernel faults can be complex, increasing maintenance overhead.

1. Apply the latest Linux kernel patches that address CVE-2024-26989 as soon as they become available from trusted Linux distributions or upstream sources. 2. For systems where immediate patching is not feasible, consider disabling hibernation or suspend-to-disk functionality on affected arm64 devices to avoid triggering the fault. 3. Review kernel boot parameters and configurations to avoid combinations (e.g., rodata=off, debug_pagealloc=off, CONFIG_KFENCE=n) that exacerbate the issue during testing or deployment. 4. Implement robust monitoring of system logs and kernel oops reports to detect early signs of this fault in production environments. 5. For critical systems, maintain tested backups and recovery procedures to minimize downtime in case of crashes. 6. Engage with hardware and Linux distribution vendors to confirm patch availability and compatibility with existing systems. 7. Consider isolating or segmenting arm64 Linux systems in network architecture to limit impact scope in case of instability.