CVE-2026-72212

Received Received - Intake

Memory Corruption in Linux Kernel Memory Hotplug

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: mm/memory_hotplug: fix incorrect altmap passing in error path In create_altmaps_and_memory_blocks(), when arch_add_memory() succeeds with memmap_on_memory enabled, the vmemmap pages are allocated from params.altmap. If create_memory_block_devices() subsequently fails, the error path calls arch_remove_memory() with a NULL altmap instead of params.altmap. This is a bug that could lead to memory corruption. Since altmap is NULL, vmemmap_free() falls back to freeing the vmemmap pages into the system buddy allocator via free_pages() instead of the altmap. arch_remove_memory() then immediately destroys the physical linear mapping for this memory. This injects unowned pages into the buddy allocator, causing machine checks or memory corruption if the system later attempts to allocate and use those freed pages. Fix this by passing params.altmap to arch_remove_memory() in the error path.

CVSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-05

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-04

NVD

CVE-2026-72212

EUVD

EUVD-2026-58970

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*
linux_kernel	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a memory management bug in the Linux kernel where an error path incorrectly passes a NULL altmap pointer to arch_remove_memory(). This causes vmemmap pages to be freed into the system buddy allocator instead of the intended altmap, leading to unowned pages and potential memory corruption or machine checks.

Detection Guidance

This vulnerability is specific to the Linux kernel's memory management and requires kernel-level detection. Check kernel logs for memory corruption errors or machine checks using dmesg | grep -i "memory" or dmesg | grep -i "machine check". Verify if memmap_on_memory is enabled by inspecting kernel parameters with cat /proc/cmdline | grep memmap_on_memory.

Impact Analysis

This vulnerability could cause system instability, crashes, or data corruption if exploited. It may lead to unexpected machine checks, kernel panics, or compromised memory integrity, affecting overall system reliability and security.

Compliance Impact

This vulnerability could lead to memory corruption and unowned pages being injected into the system's buddy allocator, potentially causing system instability or crashes. Such issues may impact compliance with standards like GDPR or HIPAA by compromising data integrity, availability, or security, especially if the affected system handles sensitive data.

Mitigation Strategies

Apply the kernel patch that fixes this issue by updating to a patched kernel version. If immediate patching is not possible, disable memmap_on_memory by adding memmap_on_memory=0 to kernel boot parameters and rebooting. Monitor system stability and memory usage for signs of corruption.

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