CVE-2025-39910: Linux kernel · mm/vmalloc, mm/kasan: respect gfp mask in kasan_populate_vmalloc()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 5.5 Medium · fixed in aa1b4b7a1b92743297f9da741424df4703a8e11b : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-01-14.
- Patch
- Available – fixed in aa1b4b7a1b92743297f9da741424df4703a8e11b, 79357cd06d41d0f5a11b17d7c86176e395d10ef2, 9598c83a50a5f9d57fd0c12fc08d9425c1ce9537 +1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Linux kernel to aa1b4b7a1b92743297f9da741424df4703a8e11b, 79357cd06d41d0f5a11b17d7c86176e395d10ef2, 9598c83a50a5f9d57fd0c12fc08d9425c1ce9537 or 33b95d90427cb4babf32059e323a6d0c027610fe.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
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.
References
- git.kernel.org/stable/c/9598c83a50a5f9d57fd0c12fc08d9425c1ce9537 (opens in a new tab)
- git.kernel.org/stable/c/aa1b4b7a1b92743297f9da741424df4703a8e11b (opens in a new tab)
- git.kernel.org/stable/c/33b95d90427cb4babf32059e323a6d0c027610fe (opens in a new tab)
- git.kernel.org/stable/c/79357cd06d41d0f5a11b17d7c86176e395d10ef2 (opens in a new tab)