{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.113-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "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:  vc_screen: reload vc pointer before if (ret) in vcs_write() to avoid UAF  The reload of 'vc' added by commit 8fb9ea65c9d1 (\"vc_screen: reload load of struct vc_data pointer in vcs_write() to avoid UAF\") sits after the 'if (ret)' block, so the copy-failure break path exits the loop without reloading vc. If the vc was kfree()'d via vc_port_destruct during the unlocked copy_from_user() window, the post-loop 'if (written \u0026\u0026 vc) vcs_scr_updated(vc)' is reached with a stale non-NULL vc. The '\u0026\u0026 vc' guard from commit a287620312dc (\"vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write\") only handles the NULL case, not this stale-non-NULL case; vcs_notifier() then reads param-\u003evc-\u003evc_num from freed memory:    BUG: KASAN: slab-use-after-free in vcs_notifier+0x7c/0xd0   Read of size 2 at addr ffff888007149190   Call Trace:    vcs_notifier+0x7c/0xd0    atomic_notifier_call_chain+0x70/0xa0    vcs_scr_updated+0x77/0xa0    vcs_write+0x71b/0x7e0   Allocated by task: vc_allocate -\u003e con_install -\u003e tty_open   Freed by task: kfree \u003c- vt_ioctl (VT_DISALLOCATE -\u003e vc_port_destruct)  Move the reload to immediately after console_lock(), before 'if (ret)', so every break path below passes a fresh vc to the post-loop vcs_scr_updated().",
  "id": "DEBIAN-CVE-2026-98840",
  "modified": "2026-10-19T04:47:29.809131962Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-98840"
    }
  ],
  "upstream": [
    "CVE-2026-98840"
  ]
}