{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.2.11-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  namespace: remove the fsnotify marks of a mount namespace in process context  mnt_ns_release() drops the last passive reference of a mount namespace and removes its fanotify marks via fsnotify_mntns_delete(). That takes the mutex of every group with a mark on the namespace and the spinlock of the connector. Fine from process context. But mnt_ns_tree_remove() hands the reference the namespace was allocated with to call_rcu() and so the marks are removed from the RCU softirq:    BUG: sleeping function called from invalid context at kernel/locking/mutex.c:623   in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/3    __mutex_lock+0x113/0x24b0    fsnotify_destroy_marks+0x11b/0x3d0    mnt_ns_release_rcu+0x57/0xa0    rcu_core+0x6b6/0x1e40  and lockdep complains about the connector lock being taken from softirq context. A fanotify group with a FAN_MARK_MNTNS mark on the mount namespace of another task is all that's needed. Root in a user namespace can do that for a mount namespace it owns. The task exits and the namespace is freed with the mark still on it.  Remove the marks in free_mnt_ns() before the namespace is handed to RCU. That runs in process context once the last active reference is gone. A mark is added through a file descriptor to the namespace which holds an active reference so no mark can show up after that.",
  "id": "DEBIAN-CVE-2026-98986",
  "modified": "2026-10-24T05:47:31.887905675Z",
  "published": "2026-10-23T13:17:20.540Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98986"
    }
  ],
  "upstream": [
    "CVE-2026-98986"
  ]
}