CVE-2025-38085: Linux kernel · mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1092.99~20.04.1 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:29 UTC
- Patch
- Available – fixed in 5.15.0-1092.99~20.04.1, 5.15.0-1096.105~20.04.1, 5.15.0-1092.101~20.04.1 +63
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 Jun 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 to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7774-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7775-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7776-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7775-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7775-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7833-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7834-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7833-2 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available and has been released in multiple patched Linux kernel versions, including 5.15.0-1092.99 and later. Users should apply the relevant Ubuntu security updates (e.g., USN-7774-2 and related notices) and reboot systems to activate the patches. Due to ABI changes, recompilation and reinstallation of third-party kernel modules may be necessary. No additional mitigation is required beyond applying the official patches.
Description
CVE-2025-38085 is a race condition vulnerability in the Linux kernel's huge page management subsystem. The flaw occurs in the huge_pmd_unshare() function, which may drop a reference on a shared page table, potentially causing unrelated virtual memory areas (VMAs) from another process to be installed. This can lead to a concurrent gup_fast() walking page tables of another process, which is unexpected behavior. The issue has been fixed by introducing an explicit broadcast IPI to synchronize TLB removal. The vulnerability affects multiple Linux kernel versions and has been patched in several 5.15.x releases.
References
- ubuntu.com/security/CVE-2025-38085 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38085 (opens in a new tab)
- git.kernel.org/linus/1013af4f585fccc4d3e5c5824d174de2257f7d6d (opens in a new tab)
- git.kernel.org/stable/c/034a52b5ef57c9c8225d94e9067f3390bb33922f (opens in a new tab)
- git.kernel.org/stable/c/1013af4f585fccc4d3e5c5824d174de2257f7d6d (opens in a new tab)
- git.kernel.org/stable/c/952596b08c74e8fe9e2883d1dc8a8f54a37384ec (opens in a new tab)
- git.kernel.org/stable/c/a3d864c901a300c295692d129159fc3001a56185 (opens in a new tab)
- git.kernel.org/stable/c/a6bfeb97941a9187833b526bc6cc4ff5706d0ce9 (opens in a new tab)
- git.kernel.org/stable/c/b7754d3aa7bf9f62218d096c0c8f6c13698fac8b (opens in a new tab)
- git.kernel.org/stable/c/fe684290418ef9ef76630072086ee530b92f02b8 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7775-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7776-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7775-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7775-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7774-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7833-1 (opens in a new tab)