{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.10-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  sched/cache: Introduce task_struct-\u003esched_cache_grp to fix UAF  Add a sched_cache_grp pointer to task_struct so that scheduler code can access the cache group directly via the task, without going through mm-\u003esched_cache_grp.  This decouples the scheduler's hot-path accesses from the mm_struct.  Each task holds its own refcount on the sched_cache_group, separate from the reference held by its mm_struct.  The reference is acquired in copy_mm() (fork) and exec_mmap() (exec), and released in exit_mm(). This fixes the use-after-free when account_mm_sched() reaches the group through a task whose mm is being switched, as reported by Hyunwoo:    https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/  Convert all scheduler code in fair.c and exit.c to use p-\u003esched_cache_grp instead of p-\u003emm-\u003esched_cache_grp.  Keep the fork/exec/exit reference management out of the generic mm paths: add sched_cache_fork(), sched_cache_fork_cleanup(), sched_cache_exec_mmap() and sched_cache_exit_mm() in kernel/sched/cache_sched.c (with empty stubs for !CONFIG_SCHED_CACHE), so fs/exec.c, kernel/fork.c and kernel/exit.c each call one helper instead of open-coding the refcounting under #ifdef.  Also add sched_cache_group_get() and task_cache_group_get().",
  "id": "DEBIAN-CVE-2026-98866",
  "modified": "2026-10-19T04:47:38.608322856Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98866"
    }
  ],
  "upstream": [
    "CVE-2026-98866"
  ]
}