CVE-2025-39725
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-05

Last updated on: 2025-11-25

Assigner: kernel.org

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 [[email protected]: add comment to unmap_poisoned_folio()]
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2025-09-05
Last Modified
2025-11-25
Generated
2026-05-07
AI Q&A
2025-09-05
EPSS Evaluated
2026-05-05
NVD
CVE-2025-39725
Affected Vendors & Products
Showing 9 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability occurs in the Linux kernel's memory management system, specifically in the handling of hardware-poisoned large memory pages (folios) during memory reclamation. When the system tries to reclaim memory from a large folio that has been marked as hardware-poisoned, the existing function unmap_poisoned_folio() cannot properly handle large folios, leading to a null pointer dereference and potentially triggering a kernel panic. The issue arises from a race condition between memory reclaim and memory failure handling, where the large folio is not correctly unmapped, causing system instability.


How can this vulnerability impact me? :

This vulnerability can cause a kernel panic, which is a critical system crash in the Linux kernel. Such a crash can lead to system downtime, data loss, and disruption of services running on the affected system. Since it involves memory management, it can affect system stability and reliability, especially under conditions where memory errors and reclamation occur simultaneously.


Ask Our AI Assistant
Need more information? Ask your question to get an AI reply (Powered by our expertise)
0/70
EPSS Chart