{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-21638",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2025-21638"
  ],
  "published": "2025-01-19T10:18:03Z",
  "summary": "sctp: sysctl: auth_enable: avoid using current->nsproxy",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsctp: sysctl: auth_enable: avoid using current->nsproxy\n\nAs mentioned in a previous commit of this series, using the 'net'\nstructure via 'current' is not recommended for different reasons:\n\n- Inconsistency: getting info from the reader's/writer's netns vs only\n  from the opener's netns.\n\n- current->nsproxy can be NULL in some cases, resulting in an 'Oops'\n  (null-ptr-deref), e.g. when the current task is exiting, as spotted by\n  syzbot [1] using acct(2).\n\nThe 'net' structure can be obtained from the table->data using\ncontainer_of().\n\nNote that table->data could also be used directly, but that would\nincrease the size of this fix, while 'sctp.ctl_sock' still needs to be\nretrieved from 'net' structure.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.21-1+rpt1",
        "1:6.1.47-1+rpt2",
        "1:6.1.47-1+rpt4",
        "1:6.1.54-1+rpt2",
        "1:6.1.58-1+rpt2",
        "1:6.1.63-1+rpt1",
        "1:6.1.73-1+rpt1",
        "1:6.6.20-1+rpt1",
        "1:6.6.28-1+rpt1",
        "1:6.6.31-1+rpt1",
        "1:6.6.47-1+rpt1",
        "1:6.6.51-1+rpt1",
        "1:6.6.51-1+rpt2",
        "1:6.6.51-1+rpt3",
        "1:6.6.62-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v6",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v8",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi2-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi2-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi2-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi2-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-2712",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-v6",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-v7",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-v7l",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi4-rpi-v8",
            "binary_version": "1:6.1.54-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-2712",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-v6",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-v7",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-v7l",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi6-rpi-v8",
            "binary_version": "1:6.1.58-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-2712",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-v6",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-v7",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-v7l",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi7-rpi-v8",
            "binary_version": "1:6.1.63-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-2712",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-v6",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-v7",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-v7l",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi8-rpi-v8",
            "binary_version": "1:6.1.73-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-2712",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-v6",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-v7",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-v7l",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.20+rpt-rpi-v8",
            "binary_version": "1:6.6.20-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-2712",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-v6",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-v7",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-v7l",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.28+rpt-rpi-v8",
            "binary_version": "1:6.6.28-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-2712",
            "binary_version": "1:6.6.31-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-v6",
            "binary_version": "1:6.6.31-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-v7",
            "binary_version": "1:6.6.31-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-v7l",
            "binary_version": "1:6.6.31-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.31+rpt-rpi-v8",
            "binary_version": "1:6.6.31-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-2712",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v6",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v7",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v7l",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.47+rpt-rpi-v8",
            "binary_version": "1:6.6.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-2712",
            "binary_version": "1:6.6.51-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v6",
            "binary_version": "1:6.6.51-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v7",
            "binary_version": "1:6.6.51-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v7l",
            "binary_version": "1:6.6.51-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v8",
            "binary_version": "1:6.6.51-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-2712",
            "binary_version": "1:6.6.51-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v6",
            "binary_version": "1:6.6.51-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v7",
            "binary_version": "1:6.6.51-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v7l",
            "binary_version": "1:6.6.51-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v8",
            "binary_version": "1:6.6.51-1+rpt2"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-2712",
            "binary_version": "1:6.6.51-1+rpt3"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v6",
            "binary_version": "1:6.6.51-1+rpt3"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v7",
            "binary_version": "1:6.6.51-1+rpt3"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v7l",
            "binary_version": "1:6.6.51-1+rpt3"
          },
          {
            "binary_name": "linux-image-6.6.51+rpt-rpi-v8",
            "binary_version": "1:6.6.51-1+rpt3"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-2712",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v6",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v7",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v7l",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v8",
            "binary_version": "1:6.6.62-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.21-1+rpt1": {
            "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed",
            "upstream_version": "6.1.21",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.125"
          },
          "1:6.1.47-1+rpt2": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.125"
          },
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.125",
            "compiled_filter": false
          },
          "1:6.1.54-1+rpt2": {
            "linux_commit": "2906f7abdc03d4a92b6b0e2e0c87ea2a9dffe8f7",
            "upstream_version": "6.1.54",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.125"
          },
          "1:6.1.58-1+rpt2": {
            "linux_commit": "ccf1586ad0663fa91238ac56abf6340d6d740d18",
            "upstream_version": "6.1.58",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.125"
          },
          "1:6.1.63-1+rpt1": {
            "linux_commit": null,
            "upstream_version": "6.1.63",
            "assessment": "upstream version (no usable Linux commit)",
            "upstream_fixed": "6.1.125"
          },
          "1:6.1.73-1+rpt1": {
            "linux_commit": null,
            "upstream_version": "6.1.73",
            "assessment": "upstream version (no usable Linux commit)",
            "upstream_fixed": "6.1.125"
          },
          "1:6.6.20-1+rpt1": {
            "linux_commit": "6f16847710cc0502450788b9f12f0a14d3429668",
            "upstream_version": "6.6.20",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.72"
          },
          "1:6.6.28-1+rpt1": {
            "linux_commit": "0c341f47adc3578cd5f817aa20ee2b7f9ae6b23e",
            "upstream_version": "6.6.28",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.72"
          },
          "1:6.6.31-1+rpt1": {
            "linux_commit": "c1432b4bae5b6582f4d32ba381459f33c34d1424",
            "upstream_version": "6.6.31",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.72"
          },
          "1:6.6.47-1+rpt1": {
            "linux_commit": "cf64a1dfecc2dc418efdd61701c1a4b185ab4761",
            "upstream_version": "6.6.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.72"
          },
          "1:6.6.51-1+rpt1": {
            "linux_commit": "0094eba3f2a4338cfa6854b0b5104d02ba0fa01f",
            "upstream_version": "6.6.51",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.72"
          },
          "1:6.6.51-1+rpt2": {
            "linux_commit": "82a50e430ef1d6eb37d78e25aa572c1f6ea56160",
            "upstream_version": "6.6.51",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.72"
          },
          "1:6.6.51-1+rpt3": {
            "linux_commit": "5aeecea9f4a45248bcf564dec924965e066a7bfd",
            "upstream_version": "6.6.51",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.72"
          },
          "1:6.6.62-1+rpt1": {
            "linux_commit": "dd2394360860d15146c96635796a75b05bb32b61",
            "upstream_version": "6.6.62",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.72"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-21638"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/cf387cdebfaebae228dfba162f94c567a67610c3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/dc583e7e5f8515ca489c0df28e4362a70eade382"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bd2a2939423566c654545fa3e96a656662a0af9e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1b67030d39f2b00f94ac1f0af11ba6657589e4d3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7ec30c54f339c640aa7e49d7e9f7bbed6bd42bf6"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c184bc621e3cef03ac9ba81a50dda2dae6a21d36"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/15649fd5415eda664ef35780c2013adeb5d9c695"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T12:19:11Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.1,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - Despite living in net/sctp/, `proc_sctp_do_auth()` is a procfs sysctl ->proc_handler that no received SCTP packet, socket, or association path ever invokes; it is reached only through local file I/O on /proc/sys/net/sctp/auth_enable and local syscalls (write(2), acct(2)).\nAC:L - Both trigger paths are fully deterministic and entirely attacker-scripted \u2014 unshare/open/SCM_RIGHTS/write for the netns-confusion path, or acct(2) plus lazy umount plus process exit for the NULL deref \u2014 with no race, no victim state, and no memory-layout dependency.\nPR:L - An unprivileged local user reaches the flaw via unprivileged user namespaces (default-enabled on Ubuntu/Debian/Fedora/Android), since cap_capable() grants the owner of a child user namespace CAP_NET_ADMIN over it (security/commoncap.c:92), letting a process still in the init netns write through the child's sysctl fd and have the handler act on init_net; only the secondary acct(2) oops path additionally needs CAP_SYS_PACCT.\nUI:N - The attacker performs every step from its own cooperating processes \u2014 namespace creation, fd passing, the write, or acct(2) and its own exit \u2014 with no action required from any other user or administrator.\nS:U - The flawed code and the affected resources are both kernel network-namespace state under the same kernel security authority; per kernel CNA convention namespace boundary crossings inside the kernel are scored Unchanged, and no hypervisor, IOMMU, or VM boundary is involved.\nC:N - The NULL+0x28 dereference faults before any data is returned to userspace, and the read side of the netns confusion only reports the caller's own netns value for a world-readable (0644) setting, so no protected information is disclosed.\nI:H - The netns confusion lets an unprivileged local user write init_net.sctp.auth_enable and directly mutate the host control socket's endpoint (sctp_sk(net->sctp.ctl_sock)->ep->auth_enable); clearing it makes every newly created host endpoint skip sctp_auth_init() and stop negotiating RFC 4895 AUTH, disabling SCTP chunk authentication host-wide \u2014 an attacker-chosen modification of protected host state and a bypass of a security control.\nA:H - The NULL-ptr-deref oopses inside do_exit() after exit_task_namespaces() while acct->lock is held under mnt_pin_kill(), wedging the task mid-teardown with a permanently held mutex and pinned mount, and panicking outright on the panic_on_oops builds common in embedded, automotive, and hardened deployments."
    }
  }
}