CVE-2025-38085

high

Published 2025-08-18 · Modified 2025-08-22

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CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

8.0

Description

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race huge_pmd_unshare() drops a reference on a page table that may have previously been shared across processes, potentially turning it into a normal page table used in another process in which unrelated VMAs can afterwards be installed. If this happens in the middle of a concurrent gup_fast(), gup_fast() could end up walking the page tables of another process. While I don't see any way in which that immediately leads to kernel memory corruption, it is really weird and unexpected. Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(), just like we do in khugepaged when removing page tables for a THP collapse.

Predictions

Exploit likelihood

20%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

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OS impact

OS	Version	Status	Fixed in
rhel	9	fixed
rocky	8	fixed
sles		affected
debian	bookworm	fixed	`6.1.147-1`
debian	bullseye	fixed	`5.10.244-1`
debian	forky	fixed	`6.12.35-1`
debian	sid	fixed	`6.12.35-1`
debian	trixie	fixed	`6.12.35-1`
almalinux	9	fixed	`kernel-debug-devel-5.14.0-570.35.1.el9_6.aarch64.rpm`

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.