{"cve":"CVE-2025-39725","nvd":{"published":"2025-09-05T18:15:50.320","modified":"2026-10-19T21:10:00.160","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list\n\nIn shrink_folio_list(), the hwpoisoned folio may be large folio, which\ncan't be handled by unmap_poisoned_folio().  For THP, try_to_unmap_one()\nmust be passed with TTU_SPLIT_HUGE_PMD to split huge PMD first and then\nretry.  Without TTU_SPLIT_HUGE_PMD, we will trigger null-ptr deref of\npvmw.pte.  Even we passed TTU_SPLIT_HUGE_PMD, we will trigger a\nWARN_ON_ONCE due to the page isn't in swapcache.\n\nSince UCE is rare in real world, and race with reclaimation is more rare,\njust skipping the hwpoisoned large folio is enough.  memory_failure() will\nhandle it if the UCE is triggered again.\n\nThis happens when memory reclaim for large folio races with\nmemory_failure(), and will lead to kernel panic.  The race is as\nfollows:\n\ncpu0      cpu1\n shrink_folio_list memory_failure\n  TestSetPageHWPoison\n  unmap_poisoned_folio\n  --> trigger BUG_ON due to\n  unmap_poisoned_folio couldn't\n   handle large folio\n\n[tujinjiang@huawei.com: add comment to unmap_poisoned_folio()]","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/656eaddbc952e1baae2f69281c22debe22140312","https://git.kernel.org/stable/c/9f1e8cd0b7c4c944e9921b52a6661b5eda2705ab","https://git.kernel.org/stable/c/c1101113d45838a823188ae25c61af97552a28ae"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-39725","score":0.00146,"percentile":0.03835,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}