{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-71080",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-01-13T15:30:19.648Z",
        "datePublished": "2026-01-13T15:34:44.832Z",
        "dateUpdated": "2026-08-05T12:11:55.485Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:11:55.485Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT\n\nOn PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the\ncurrent task can be preempted. Another task running on the same CPU\nmay then execute rt6_make_pcpu_route() and successfully install a\npcpu_rt entry. When the first task resumes execution, its cmpxchg()\nin rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer\nNULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding\nmdelay() after rt6_get_pcpu_route().\n\nUsing preempt_disable/enable is not appropriate here because\nip6_rt_pcpu_alloc() may sleep.\n\nFix this by handling the cmpxchg() failure gracefully on PREEMPT_RT:\nfree our allocation and return the existing pcpu_rt installed by\nanother task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT\nkernels where such races should not occur."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:N - Unauthenticated IPv6 packets reach ip6_route_input() and ip6_pol_route() before transport delivery or authentication, exposing the vulnerable per-CPU route creation path to a remote peer.\nAC:L - In a reasonable multi-queue or threaded-network PREEMPT_RT deployment, concurrent attacker-driven packet streams can exercise both sides of the short empty-slot race repeatedly. No memory-layout guess or inherently uncontrollable condition is required.\nPR:N - The inbound IPv6 routing path performs no capability or authentication check before reaching the vulnerable code.\nUI:N - No victim action is required; processing attacker-generated IPv6 traffic triggers route lookup automatically.\nS:U - The resulting kernel failure affects the same host and security authority in which packet processing occurs, without crossing a virtualization or sandbox boundary.\nC:N - The failed cmpxchg only detects an already-installed valid route and immediately reaches BUG_ON; it provides no memory disclosure or read primitive.\nI:N - The atomic installation fails without overwriting the existing pointer, and there is no use-after-free, out-of-bounds write, or other attacker-controlled modification.\nA:H - BUG_ON executes while bottom halves are disabled and raises a fatal invalid-opcode oops, which can directly produce a kernel panic and complete system outage."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv6/route.c"
                    ],
                    "versions": [
                        {
                            "version": "d2d6422f8bd17c6bb205133e290625a564194496",
                            "lessThan": "1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "d2d6422f8bd17c6bb205133e290625a564194496",
                            "lessThan": "787515ccb2292f82eb0876993129154629a49651",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "d2d6422f8bd17c6bb205133e290625a564194496",
                            "lessThan": "1adaea51c61b52e24e7ab38f7d3eba023b2d050d",
                            "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/ipv6/route.c"
                    ],
                    "versions": [
                        {
                            "version": "6.12",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.12",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.64",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.4",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.19",
                            "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": "6.12",
                                    "versionEndExcluding": "6.12.64"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.12",
                                    "versionEndExcluding": "6.18.4"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.12",
                                    "versionEndExcluding": "6.19"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66"
                },
                {
                    "url": "https://git.kernel.org/stable/c/787515ccb2292f82eb0876993129154629a49651"
                },
                {
                    "url": "https://git.kernel.org/stable/c/1adaea51c61b52e24e7ab38f7d3eba023b2d050d"
                }
            ],
            "title": "ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}