{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"
            },
            {
              "fixed": "c96549d07dfdd51aadf0722cfb40711574424840"
            },
            {
              "fixed": "1c8bda3df028d5e54134077dcd09f46ca8cfceb5"
            },
            {
              "fixed": "3e1a8b00095246a9a2b46b57f6d471c6d3c00ed2"
            },
            {
              "fixed": "e3f80666c2739296c3b69a127300455c43aa1067"
            },
            {
              "fixed": "21c303fec138c002f90ed33bce60e807d53072bb"
            },
            {
              "fixed": "69d3f9ee5489e6e8b66defcfa226e91d82393297"
            },
            {
              "fixed": "440c9a5fc477a8ee259d8bf669531250b8398651"
            },
            {
              "fixed": "ae88a5d2f29b69819dc7b04086734439d074a643"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.12"
            },
            {
              "fixed": "5.10.252"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.202"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.165"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.128"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.75"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.14"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31411.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: atm: fix crash due to unvalidated vcc pointer in sigd_send()\n\nReproducer available at [1].\n\nThe ATM send path (sendmsg -\u003e vcc_sendmsg -\u003e sigd_send) reads the vcc\npointer from msg-\u003evcc and uses it directly without any validation. This\npointer comes from userspace via sendmsg() and can be arbitrarily forged:\n\n    int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0);\n    ioctl(fd, ATMSIGD_CTRL);  // become ATM signaling daemon\n    struct msghdr msg = { .msg_iov = \u0026iov, ... };\n    *(unsigned long *)(buf + 4) = 0xdeadbeef;  // fake vcc pointer\n    sendmsg(fd, \u0026msg, 0);  // kernel dereferences 0xdeadbeef\n\nIn normal operation, the kernel sends the vcc pointer to the signaling\ndaemon via sigd_enq() when processing operations like connect(), bind(),\nor listen(). The daemon is expected to return the same pointer when\nresponding. However, a malicious daemon can send arbitrary pointer values.\n\nFix this by introducing find_get_vcc() which validates the pointer by\nsearching through vcc_hash (similar to how sigd_close() iterates over\nall VCCs), and acquires a reference via sock_hold() if found.\n\nSince struct atm_vcc embeds struct sock as its first member, they share\nthe same lifetime. Therefore using sock_hold/sock_put is sufficient to\nkeep the vcc alive while it is being used.\n\nNote that there may be a race with sigd_close() which could mark the vcc\nwith various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns.\nHowever, sock_hold() guarantees the memory remains valid, so this race\nonly affects the logical state, not memory safety.\n\n[1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3",
  "id": "CVE-2026-31411",
  "modified": "2026-07-08T05:36:23.475112656Z",
  "published": "2026-04-08T13:06:17.800Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1c8bda3df028d5e54134077dcd09f46ca8cfceb5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/21c303fec138c002f90ed33bce60e807d53072bb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3e1a8b00095246a9a2b46b57f6d471c6d3c00ed2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/440c9a5fc477a8ee259d8bf669531250b8398651"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/69d3f9ee5489e6e8b66defcfa226e91d82393297"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ae88a5d2f29b69819dc7b04086734439d074a643"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c96549d07dfdd51aadf0722cfb40711574424840"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e3f80666c2739296c3b69a127300455c43aa1067"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31411.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31411"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "net: atm: fix crash due to unvalidated vcc pointer in sigd_send()"
}