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CVE-2025-39725

MEDIUMCVSS 5.5/10EPSS 0.14%

Last modified

CVE-2025-39725 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list In shrink_folio_list(), the hwpoisoned folio may be large folio, which can't be handled by unmap_poisoned_folio(). For THP, try_to_unmap_one() must be passed with TTU_SPLIT_HUGE_PMD to split huge PMD first and then retry. EPSS estimates a 0.14% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list In shrink_folio_list(), the hwpoisoned folio may be large folio, which can't be handled by unmap_poisoned_folio(). For THP, try_to_unmap_one() must be passed with TTU_SPLIT_HUGE_PMD to split huge PMD first and then retry. Without TTU_SPLIT_HUGE_PMD, we will trigger null-ptr deref of pvmw.pte. Even we passed TTU_SPLIT_HUGE_PMD, we will trigger a WARN_ON_ONCE due to the page isn't in swapcache. Since UCE is rare in real world, and race with reclaimation is more rare, just skipping the hwpoisoned large folio is enough. memory_failure() will handle it if the UCE is triggered again. This happens when memory reclaim for large folio races with memory_failure(), and will lead to kernel panic. The race is as follows: cpu0 cpu1 shrink_folio_list memory_failure TestSetPageHWPoison unmap_poisoned_folio --> trigger BUG_ON due to unmap_poisoned_folio couldn't handle large folio [tujinjiang@huawei.com: add comment to unmap_poisoned_folio()]

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.14%

3.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 6.12.26, < 6.12.41—
LinuxLinux Kernel>= 6.14.5, < 6.15.9—
LinuxLinux Kernel6.16Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2025-39725?
In the Linux kernel, the following vulnerability has been resolved: mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list In shrink_folio_list(), the hwpoisoned folio may be large folio, which can't be handled by unmap_poisoned_folio(). For THP, try_to_unmap_one() must be passed with TTU_SPLIT_HUGE_PMD to split huge PMD first and then retry. Without TTU_SPLIT_HUGE_PMD, we will trigger null-ptr deref of pvmw.pte. Even we passed TTU_SPLIT_HUGE_PMD, we will trigger a WARN_ON_ONCE due to the page isn't in swapcache. Since UCE is rare in real world, and race with reclaimation is more rare, just skipping the hwpoisoned large folio is enough. memory_failure() will handle it if the UCE is triggered again. This happens when memory reclaim for large folio races with memory_failure(), and will lead to kernel panic. The race is as follows: cpu0 cpu1 shrink_folio_list memory_failure TestSetPageHWPoison unmap_poisoned_folio --> trigger BUG_ON due to unmap_poisoned_folio couldn't handle large folio [tujinjiang@huawei.com: add comment to unmap_poisoned_folio()]
How severe is CVE-2025-39725?
CVE-2025-39725 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.14% probability of exploitation in the next 30 days.
How do I fix CVE-2025-39725?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-39725?

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Source: NVD / NIST