{"cve":"CVE-2024-42234","nvd":{"published":"2024-08-07T16:15:46.390","modified":"2026-08-04T11:19:40.463","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: fix crashes from deferred split racing folio migration\n\nEven on 6.10-rc6, I've been seeing elusive \"Bad page state\"s (often on\nflags when freeing, yet the flags shown are not bad: PG_locked had been\nset and cleared??), and VM_BUG_ON_PAGE(page_ref_count(page) == 0)s from\ndeferred_split_scan()'s folio_put(), and a variety of other BUG and WARN\nsymptoms implying double free by deferred split and large folio migration.\n\n6.7 commit 9bcef5973e31 (\"mm: memcg: fix split queue list crash when large\nfolio migration\") was right to fix the memcg-dependent locking broken in\n85ce2c517ade (\"memcontrol: only transfer the memcg data for migration\"),\nbut missed a subtlety of deferred_split_scan(): it moves folios to its own\nlocal list to work on them without split_queue_lock, during which time\nfolio->_deferred_list is not empty, but even the \"right\" lock does nothing\nto secure the folio and the list it is on.\n\nFortunately, deferred_split_scan() is careful to use folio_try_get(): so\nfolio_migrate_mapping() can avoid the race by folio_undo_large_rmappable()\nwhile the old folio's reference count is temporarily frozen to 0 - adding\nsuch a freeze in the !mapping case too (originally, folio lock and\nunmapping and no swap cache left an anon folio unreachable, so no freezing\nwas needed there: but the deferred split queue offers a way to reach it).","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-415"],"references":["https://git.kernel.org/stable/c/be9581ea8c058d81154251cb0695987098996cad","https://git.kernel.org/stable/c/fc7facce686b64201dbf0b9614cc1d0bfad70010"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:53:51.317825789+00:00"},"epss":{"cve":"CVE-2024-42234","score":0.00194,"percentile":0.09111,"date":"2026-11-01"},"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."]}