{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-97938",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-25T10:18:58.204Z",
        "datePublished": "2026-09-25T10:22:51.720Z",
        "dateUpdated": "2026-10-21T12:53:45.385Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-21T12:53:45.385Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nreboot: fix cad_pid use-after-free race\n\ncad_pid is a single kernel-wide struct pid pointer. proc_do_cad_pid()\nreads it and passes it to pid_vnr() without protecting the lifetime of\nthe referenced struct pid. A concurrent writer can replace cad_pid and\ndrop the final reference to the old struct pid after the reader has\nloaded the pointer but before pid_vnr() has finished dereferencing it,\ncausing a use-after-free.\n\nkill_cad_pid() has the same lifetime race when it passes cad_pid to\nkill_pid().\n\nAt the time this issue was reported, an unprivileged user could reach the\nsysctl through user and PID namespaces because cad_pid was registered in\npid_table[]. Moving cad_pid back to the global reboot sysctl table\ncorrected that namespace and permission mismatch, but did not fix the\nunderlying lifetime race.\n\nFix this by treating cad_pid as an RCU-protected pointer at both read\nsites and by waiting for a grace period before dropping the old reference\non the write side.\n\ncall_rcu(&old_pid->rcu, ...) cannot be used here because free_pid()\nalso queues pid->rcu; queueing the same rcu_head twice can corrupt the\nRCU callback list.\n\nOriginal KASAN crash stack:\n  kernel/pid.c:545 pid_nr_ns()        # reads freed pid->level\n  kernel/pid.c:556 pid_vnr()          # calls pid_nr_ns()\n  kernel/pid.c:775 proc_do_cad_pid()  # calls pid_vnr(cad_pid)"
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "include/linux/sched.h",
                        "include/linux/sched/signal.h",
                        "init/main.c",
                        "kernel/reboot.c",
                        "kernel/signal.c"
                    ],
                    "versions": [
                        {
                            "version": "9ec52099e4b8678a60e9f93e41ad87885d64f3e6",
                            "lessThan": "0c1a966bc047af2801a70b8eb13f9df5d7ab925f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9ec52099e4b8678a60e9f93e41ad87885d64f3e6",
                            "lessThan": "ae3e53fe3c1241855e3a88f74877738349948c78",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9ec52099e4b8678a60e9f93e41ad87885d64f3e6",
                            "lessThan": "ad72e2566643fff7f01666d845fb026898155e1f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9ec52099e4b8678a60e9f93e41ad87885d64f3e6",
                            "lessThan": "9a17b0e053197a6a42cdc75e75a35b17aa662088",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9ec52099e4b8678a60e9f93e41ad87885d64f3e6",
                            "lessThan": "5a88f78df753993469dab4d1831f8fb4256a9468",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "include/linux/sched.h",
                        "include/linux/sched/signal.h",
                        "init/main.c",
                        "kernel/reboot.c",
                        "kernel/signal.c"
                    ],
                    "versions": [
                        {
                            "version": "2.6.19",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "2.6.19",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.160",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.112",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.53",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.7",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "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": "2.6.19",
                                    "versionEndExcluding": "6.6.160"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.19",
                                    "versionEndExcluding": "6.12.112"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.19",
                                    "versionEndExcluding": "6.18.53"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.19",
                                    "versionEndExcluding": "7.2.7"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.19",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/0c1a966bc047af2801a70b8eb13f9df5d7ab925f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/ae3e53fe3c1241855e3a88f74877738349948c78"
                },
                {
                    "url": "https://git.kernel.org/stable/c/ad72e2566643fff7f01666d845fb026898155e1f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/9a17b0e053197a6a42cdc75e75a35b17aa662088"
                },
                {
                    "url": "https://git.kernel.org/stable/c/5a88f78df753993469dab4d1831f8fb4256a9468"
                }
            ],
            "title": "reboot: fix cad_pid use-after-free race",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}