{"api_version":"1","generated_at":"2026-08-28T23:59:19+00:00","cve":"CVE-2026-80719","urls":{"html":"https://cve.report/CVE-2026-80719","api":"https://cve.report/api/cve/CVE-2026-80719.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80719","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80719"},"summary":{"title":"mm: mglru: fix stale batch updates after memcg reparenting","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: mglru: fix stale batch updates after memcg reparenting\n\nThe mglru page table walker batches per-generation size deltas in\nwalk->nr_pages while walking page tables without holding the lruvec lock. \nThe reset_batch_size() later folds those deltas into walk->lruvec under\nthe lruvec lock.\n\nThe page table walker can run concurrently with the memcg reparenting path\nas follows:\n\nCPU0                           CPU1\n====                           ====\n\nwalk_mm\n--> walk_page_range\n    --> update_batch_size\n        --> walk->nr_pages += delta\n\n                              mem_cgroup_css_offline\n                              --> memcg_reparent_objcgs\n                                  --> lock lruvec\n                                      lru_gen_reparent_memcg\n                                      --> reparent child folios to parent\n                                      unlock lruvec\n\n    lock lruvec\n    reset_batch_size\n    --> child lrugen->nr_pages += delta\n\nThis will trigger the following warning in lru_gen_exit_memcg():\n\n\tVM_WARN_ON_ONCE(memchr_inv(lruvec->lrugen.nr_pages, 0,\n\t\t\t\t   sizeof(lruvec->lrugen.nr_pages)));\n\nAnd the user-visible impact of underestimated nr_pages in MGLRU was\npremature OOMs because MGLRU does not try to reclaim memory when nr_pages\nreaches zero, but there are still more pages.\n\nTo fix it, make reset_batch_size() check CSS_DYING under RCU before\nflushing the pending batch.  A non-dying memcg keeps the original lruvec\nstable against RCU-delayed offlining; a dying memcg redirects the deltas\nto the first non-dying ancestor.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-28 08:16:57","updated_at":"2026-08-28 08:16:57"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/de4660898b7aa7e03d3b120a6bfa6b26211e4e77","name":"https://git.kernel.org/stable/c/de4660898b7aa7e03d3b120a6bfa6b26211e4e77","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101","name":"https://git.kernel.org/stable/c/fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80719","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80719","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f304652609eae3814b0e9d11c75c0e0cb62da31f fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f304652609eae3814b0e9d11c75c0e0cb62da31f de4660898b7aa7e03d3b120a6bfa6b26211e4e77 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.8 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["include/linux/memcontrol.h","mm/vmscan.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101","status":"affected","version":"f304652609eae3814b0e9d11c75c0e0cb62da31f","versionType":"git"},{"lessThan":"de4660898b7aa7e03d3b120a6bfa6b26211e4e77","status":"affected","version":"f304652609eae3814b0e9d11c75c0e0cb62da31f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["include/linux/memcontrol.h","mm/vmscan.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.8","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.8","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"7.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: mglru: fix stale batch updates after memcg reparenting\n\nThe mglru page table walker batches per-generation size deltas in\nwalk->nr_pages while walking page tables without holding the lruvec lock. \nThe reset_batch_size() later folds those deltas into walk->lruvec under\nthe lruvec lock.\n\nThe page table walker can run concurrently with the memcg reparenting path\nas follows:\n\nCPU0                           CPU1\n====                           ====\n\nwalk_mm\n--> walk_page_range\n    --> update_batch_size\n        --> walk->nr_pages += delta\n\n                              mem_cgroup_css_offline\n                              --> memcg_reparent_objcgs\n                                  --> lock lruvec\n                                      lru_gen_reparent_memcg\n                                      --> reparent child folios to parent\n                                      unlock lruvec\n\n    lock lruvec\n    reset_batch_size\n    --> child lrugen->nr_pages += delta\n\nThis will trigger the following warning in lru_gen_exit_memcg():\n\n\tVM_WARN_ON_ONCE(memchr_inv(lruvec->lrugen.nr_pages, 0,\n\t\t\t\t   sizeof(lruvec->lrugen.nr_pages)));\n\nAnd the user-visible impact of underestimated nr_pages in MGLRU was\npremature OOMs because MGLRU does not try to reclaim memory when nr_pages\nreaches zero, but there are still more pages.\n\nTo fix it, make reset_batch_size() check CSS_DYING under RCU before\nflushing the pending batch.  A non-dying memcg keeps the original lruvec\nstable against RCU-delayed offlining; a dying memcg redirects the deltas\nto the first non-dying ancestor."}],"providerMetadata":{"dateUpdated":"2026-08-28T06:53:16.087Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/fceb6b7f3ddec6ea9fc11577f4cf1b2da73a3101"},{"url":"https://git.kernel.org/stable/c/de4660898b7aa7e03d3b120a6bfa6b26211e4e77"}],"title":"mm: mglru: fix stale batch updates after memcg reparenting","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80719","datePublished":"2026-08-28T06:53:16.087Z","dateReserved":"2026-08-26T14:34:25.788Z","dateUpdated":"2026-08-28T06:53:16.087Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-28 08:16:57","lastModifiedDate":"2026-08-28 08:16:57","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80719","Ordinal":"1","Title":"mm: mglru: fix stale batch updates after memcg reparenting","CVE":"CVE-2026-80719","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80719","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: mglru: fix stale batch updates after memcg reparenting\n\nThe mglru page table walker batches per-generation size deltas in\nwalk->nr_pages while walking page tables without holding the lruvec lock. \nThe reset_batch_size() later folds those deltas into walk->lruvec under\nthe lruvec lock.\n\nThe page table walker can run concurrently with the memcg reparenting path\nas follows:\n\nCPU0                           CPU1\n====                           ====\n\nwalk_mm\n--> walk_page_range\n    --> update_batch_size\n        --> walk->nr_pages += delta\n\n                              mem_cgroup_css_offline\n                              --> memcg_reparent_objcgs\n                                  --> lock lruvec\n                                      lru_gen_reparent_memcg\n                                      --> reparent child folios to parent\n                                      unlock lruvec\n\n    lock lruvec\n    reset_batch_size\n    --> child lrugen->nr_pages += delta\n\nThis will trigger the following warning in lru_gen_exit_memcg():\n\n\tVM_WARN_ON_ONCE(memchr_inv(lruvec->lrugen.nr_pages, 0,\n\t\t\t\t   sizeof(lruvec->lrugen.nr_pages)));\n\nAnd the user-visible impact of underestimated nr_pages in MGLRU was\npremature OOMs because MGLRU does not try to reclaim memory when nr_pages\nreaches zero, but there are still more pages.\n\nTo fix it, make reset_batch_size() check CSS_DYING under RCU before\nflushing the pending batch.  A non-dying memcg keeps the original lruvec\nstable against RCU-delayed offlining; a dying memcg redirects the deltas\nto the first non-dying ancestor.","Type":"Description","Title":"mm: mglru: fix stale batch updates after memcg reparenting"}]}}}