{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-38542",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-04-16T04:51:24.024Z",
        "datePublished": "2025-08-16T11:22:16.689Z",
        "dateUpdated": "2026-08-05T12:02:46.709Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:02:46.709Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: appletalk: Fix device refcount leak in atrtr_create()\n\nWhen updating an existing route entry in atrtr_create(), the old device\nreference was not being released before assigning the new device,\nleading to a device refcount leak. Fix this by calling dev_put() to\nrelease the old device reference before holding the new one."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The vulnerability is reached via `ioctl(SIOCADDRT)` on a locally-created `AF_APPLETALK` socket, requiring local system access. There is no remote or adjacent-network trigger for `atrtr_create()`.\nAC:L - The leak is fully deterministic — issuing the same `SIOCADDRT` twice for one route target/flags pair leaks a reference on every subsequent call, with no race, timing window, or memory-layout dependency. The attacker controls the loop entirely and `appletalk.ko` autoloads on demand.\nPR:L - The 32-bit compat path `atalk_compat_routing_ioctl()` reaches `atrtr_create()` with no capability check whatsoever (dropped in v5.6 by dc13c8761c91c0), and `compat_sock_ioctl()` dispatches to it before any generic gating, so an ordinary unprivileged user account suffices. Only the native path enforces `capable(CAP_NET_ADMIN)`.\nUI:N - The attacker triggers the entire sequence from their own process with socket creation and repeated ioctls. No victim action or cooperation is involved.\nS:U - The leaked reference, the resulting hang, and any subsequent memory corruption are all confined to the kernel's own security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The netdev refcount is an unprotected wrappable `int` (`this_cpu_inc` on `pcpu_refcnt`, no `refcount_t` saturation), so sustained leaking wraps `netdev_refcnt_read()` and causes `free_netdev()` while live references remain. The resulting use-after-free on `struct net_device` — still referenced by routes, qdiscs and sockets — yields an arbitrary kernel read primitive after heap reclaim.\nI:H - The same refcount wrap produces a dangling `struct net_device`, an object dense with function-pointer tables (`netdev_ops`, `ethtool_ops`, `header_ops`) that is straightforward to reclaim and spray, giving a write and control-flow hijack primitive. Per kernel scoring guidance, use-after-free is rated High for integrity.\nA:H - Each leaked reference makes the device permanently unremovable — `netdev_wait_allrefs_any()` spins forever from `netdev_run_todo()`, wedging the single-threaded `cleanup_net` workqueue so all further netns teardown and RTNL device removal hangs system-wide until reboot. The `BUG_ON(netdev_refcnt_read(dev) != 1)` in `netdev_run_todo()` additionally gives a directly reachable kernel panic."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/appletalk/ddp.c"
                    ],
                    "versions": [
                        {
                            "version": "c7f905f0f6d49ed8c1aa4566c31f0383a0ba0c9d",
                            "lessThan": "b92bedf71f25303e203a4e657489d76691a58119",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c7f905f0f6d49ed8c1aa4566c31f0383a0ba0c9d",
                            "lessThan": "a7852b01793669248dce0348d14df89e77a32afd",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c7f905f0f6d49ed8c1aa4566c31f0383a0ba0c9d",
                            "lessThan": "b2f5dfa87367fdce9f8b995bc6c38f64f9ea2c90",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c7f905f0f6d49ed8c1aa4566c31f0383a0ba0c9d",
                            "lessThan": "d2e9f50f0bdad73b64a871f25186b899624518c4",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c7f905f0f6d49ed8c1aa4566c31f0383a0ba0c9d",
                            "lessThan": "4a17370da6e476d3d275534e9e9cd2d02c57ca46",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c7f905f0f6d49ed8c1aa4566c31f0383a0ba0c9d",
                            "lessThan": "473f3eadfc73b0fb6d8dee5829d19a5772e387f7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c7f905f0f6d49ed8c1aa4566c31f0383a0ba0c9d",
                            "lessThan": "64124cf0aab0dd1e18c0fb5ae66e45741e727f8b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c7f905f0f6d49ed8c1aa4566c31f0383a0ba0c9d",
                            "lessThan": "711c80f7d8b163d3ecd463cd96f07230f488e750",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/appletalk/ddp.c"
                    ],
                    "versions": [
                        {
                            "version": "2.6.12",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "2.6.12",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.4.296",
                            "lessThanOrEqual": "5.4.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.10.240",
                            "lessThanOrEqual": "5.10.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.189",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.146",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.99",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.39",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.15.7",
                            "lessThanOrEqual": "6.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.16",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "5.4.296"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "5.10.240"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "5.15.189"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "6.1.146"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "6.6.99"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "6.12.39"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "6.15.7"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.12",
                                    "versionEndExcluding": "6.16"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/b92bedf71f25303e203a4e657489d76691a58119"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a7852b01793669248dce0348d14df89e77a32afd"
                },
                {
                    "url": "https://git.kernel.org/stable/c/b2f5dfa87367fdce9f8b995bc6c38f64f9ea2c90"
                },
                {
                    "url": "https://git.kernel.org/stable/c/d2e9f50f0bdad73b64a871f25186b899624518c4"
                },
                {
                    "url": "https://git.kernel.org/stable/c/4a17370da6e476d3d275534e9e9cd2d02c57ca46"
                },
                {
                    "url": "https://git.kernel.org/stable/c/473f3eadfc73b0fb6d8dee5829d19a5772e387f7"
                },
                {
                    "url": "https://git.kernel.org/stable/c/64124cf0aab0dd1e18c0fb5ae66e45741e727f8b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/711c80f7d8b163d3ecd463cd96f07230f488e750"
                }
            ],
            "title": "net: appletalk: Fix device refcount leak in atrtr_create()",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        },
        "adp": [
            {
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
                    },
                    {
                        "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"
                    }
                ],
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2025-11-03T17:39:38.181Z"
                }
            }
        ]
    }
}