{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.8-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  mm/shrinker: fix bogus set_shrinker_bit() with cgroup.memory=nokmem  With cgroup.memory=nokmem, shrinker_memcg_alloc() bails out early and never allocates an id, so shrinker-\u003eid keeps the 0 it got from the kzalloc() in shrinker_alloc().  __list_lru_init() then copies that 0 into lru-\u003eshrinker_id, where it looks like a valid bit index.  Nothing calls expand_shrinker_info() on nokmem either, so shrinker_nr_max stays 0 and every memcg ends up with an empty map (map_nr_max == 0).  deferred_split_folio() hands a real memcg to __list_lru_add() regardless of whether the lru is memcg aware, so the first THP queued in a cgroup does set_shrinker_bit(memcg, nid, 0) and trips the bounds check:  WARNING: mm/shrinker.c:212 at set_shrinker_bit+0x7d/0x90, CPU#126 Call Trace:  \u003cTASK\u003e  deferred_split_folio+0x18c/0x220  map_anon_folio_pmd_nopf+0xdd/0x130  map_anon_folio_pmd_pf+0x14/0xb0  do_huge_pmd_anonymous_page+0x1a1/0x620  __handle_mm_fault+0xea9/0x10d0  handle_mm_fault+0xe5/0x320  do_user_addr_fault+0x1cc/0x870  exc_page_fault+0x81/0x1b0  asm_exc_page_fault+0x27/0x30  \u003c/TASK\u003e  Harmless, the WARN_ON_ONCE() is what keeps the out of bounds unit[] read from happening, but the id should not look valid in the first place.  Clear it before returning.  Two other spots could paper over this: drop the id in __list_lru_init() when nokmem turns memcg_aware off, or make deferred_split_folio() pass NULL like list_lru_add_obj() does.  Both leave shrinker-\u003eid lying around for the next caller, so fix it where the id is handed out.",
  "id": "DEBIAN-CVE-2026-98225",
  "modified": "2026-10-07T04:47:35.717643138Z",
  "published": "2026-10-06T09:18:09.587Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98225"
    }
  ],
  "upstream": [
    "CVE-2026-98225"
  ]
}