{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.19.11-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  mm/damon/sysfs: check contexts-\u003enr in repeat_call_fn  damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(), damon_sysfs_upd_schemes_stats(), and damon_sysfs_upd_schemes_effective_quotas() without checking contexts-\u003enr.  If nr_contexts is set to 0 via sysfs while DAMON is running, these functions dereference contexts_arr[0] and cause a NULL pointer dereference.  Add the missing check.  For example, the issue can be reproduced using DAMON sysfs interface and DAMON user-space tool (damo) [1] like below.      $ sudo damo start --refresh_interval 1s     $ echo 0 | sudo tee \\             /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts",
  "id": "DEBIAN-CVE-2026-31457",
  "modified": "2026-09-14T16:47:39.426128589Z",
  "published": "2026-04-22T14:16:41.133Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-31457"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-31457"
  ]
}