{"schema":"threatline.record/2","record":{"id":"CVE-2026-98225","aliases":[],"summary":"mm/shrinker: fix bogus set_shrinker_bit() with cgroup.memory=nokmem","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/shrinker: fix bogus set_shrinker_bit() with cgroup.memory=nokmem\n\nWith cgroup.memory=nokmem, shrinker_memcg_alloc() bails out early and\nnever allocates an id, so shrinker->id keeps the 0 it got from the\nkzalloc() in shrinker_alloc().  __list_lru_init() then copies that 0 into\nlru->shrinker_id, where it looks like a valid bit index.\n\nNothing calls expand_shrinker_info() on nokmem either, so shrinker_nr_max\nstays 0 and every memcg ends up with an empty map (map_nr_max == 0).\n\ndeferred_split_folio() hands a real memcg to __list_lru_add() regardless\nof whether the lru is memcg aware, so the first THP queued in a cgroup\ndoes set_shrinker_bit(memcg, nid, 0) and trips the bounds check:\n\nWARNING: mm/shrinker.c:212 at set_shrinker_bit+0x7d/0x90, CPU#126\nCall Trace:\n <TASK>\n deferred_split_folio+0x18c/0x220\n map_anon_folio_pmd_nopf+0xdd/0x130\n map_anon_folio_pmd_pf+0x14/0xb0\n do_huge_pmd_anonymous_page+0x1a1/0x620\n __handle_mm_fault+0xea9/0x10d0\n handle_mm_fault+0xe5/0x320\n do_user_addr_fault+0x1cc/0x870\n exc_page_fault+0x81/0x1b0\n asm_exc_page_fault+0x27/0x30\n </TASK>\n\nHarmless, the WARN_ON_ONCE() is what keeps the out of bounds unit[] read\nfrom happening, but the id should not look valid in the first place. \nClear it before returning.\n\nTwo other spots could paper over this: drop the id in __list_lru_init()\nwhen nokmem turns memcg_aware off, or make deferred_split_folio() pass\nNULL like list_lru_add_obj() does.  Both leave shrinker->id lying around\nfor the next caller, so fix it where the id is handed out.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98225","source_modified_at":"2026-10-19T09:15:57.057Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"fafaeceb89a5e2e856ff04c2cacb6cae4a2ecb67","lessThan":"469c12a69ab1842a9090b6c074ffedbfd9584f9c","status":"affected","versionType":"git"},{"version":"fafaeceb89a5e2e856ff04c2cacb6cae4a2ecb67","lessThan":"932cfb25e7ce98d1f93895671ec186a3087e4f80","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98225","source_modified_at":"2026-10-19T09:15:57.057Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"7.2","status":"affected"},{"version":"0","lessThan":"7.2","status":"unaffected","versionType":"semver"},{"version":"7.2.8","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98225","source_modified_at":"2026-10-19T09:15:57.057Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"469c12a69ab1842a9090b6c074ffedbfd9584f9c","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98225","source_modified_at":"2026-10-19T09:15:57.057Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"932cfb25e7ce98d1f93895671ec186a3087e4f80","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00162,"percentile":0.05095,"score_date":"2026-10-23"},"published_at":"2026-10-06T08:45:00.458Z","modified_at":"2026-10-19T09:15:57.057Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98225","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-19T09:15:57.057Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98225","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/469c12a69ab1842a9090b6c074ffedbfd9584f9c"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/932cfb25e7ce98d1f93895671ec186a3087e4f80"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-19T09:15:57.057Z","content_hash":"cca75abecb1ba77172332283fc12d53fcf61cbaa395e5bb46103081aebb5cdd4"}}