{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:11",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "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": "6.12.85-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.18.14-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  net: atm: fix crash due to unvalidated vcc pointer in sigd_send()  Reproducer available at [1].  The ATM send path (sendmsg -\u003e vcc_sendmsg -\u003e sigd_send) reads the vcc pointer from msg-\u003evcc and uses it directly without any validation. This pointer comes from userspace via sendmsg() and can be arbitrarily forged:      int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0);     ioctl(fd, ATMSIGD_CTRL);  // become ATM signaling daemon     struct msghdr msg = { .msg_iov = \u0026iov, ... };     *(unsigned long *)(buf + 4) = 0xdeadbeef;  // fake vcc pointer     sendmsg(fd, \u0026msg, 0);  // kernel dereferences 0xdeadbeef  In normal operation, the kernel sends the vcc pointer to the signaling daemon via sigd_enq() when processing operations like connect(), bind(), or listen(). The daemon is expected to return the same pointer when responding. However, a malicious daemon can send arbitrary pointer values.  Fix this by introducing find_get_vcc() which validates the pointer by searching through vcc_hash (similar to how sigd_close() iterates over all VCCs), and acquires a reference via sock_hold() if found.  Since struct atm_vcc embeds struct sock as its first member, they share the same lifetime. Therefore using sock_hold/sock_put is sufficient to keep the vcc alive while it is being used.  Note that there may be a race with sigd_close() which could mark the vcc with various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns. However, sock_hold() guarantees the memory remains valid, so this race only affects the logical state, not memory safety.  [1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3",
  "id": "DEBIAN-CVE-2026-31411",
  "modified": "2026-04-30T20:48:23.121134986Z",
  "published": "2026-04-08T14:16:27.977Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-31411"
    }
  ],
  "upstream": [
    "CVE-2026-31411"
  ]
}