CVE-2026-72212: mm/memory_hotplug: fix incorrect altmap passing in error path

Vulnerability summary

CVE-2026-72212 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.21% chance of exploitation in the next 30 days, higher than 10.6% of scored vulnerabilities.

Timeline

1. 15-08-2026
   PublishedVulnerability first disclosed.
2. 17-08-2026
   Last modifiedVulnerability information updated.

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.

No weakness data has been published for this record.