{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-40168",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-04-16T07:20:57.176Z",
        "datePublished": "2025-11-12T10:46:51.422Z",
        "dateUpdated": "2026-08-05T12:08:13.571Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:08:13.571Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match().\n\nsmc_clc_prfx_match() is called from smc_listen_work() and\nnot under RCU nor RTNL.\n\nUsing sk_dst_get(sk)->dev could trigger UAF.\n\nLet's use __sk_dst_get() and dst_dev_rcu().\n\nNote that the returned value of smc_clc_prfx_match() is not\nused in the caller."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 8.1,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:N - The vulnerable read is performed by the SMC listen worker while parsing a CLC Proposal message received over TCP from a remote peer (smc_listen_work → smc_listen_find_device → smc_listen_prfx_check → smc_clc_prfx_match), and the peer controls the fields that select and drive the code path. Any host running an AF_SMC listener is exposed to unauthenticated remote connections.\nAC:H - The attacker fully controls one side of the race (when the CLC Proposal arrives and thus when the stale dst->dev is dereferenced), but the other side requires the route's net_device to be concurrently torn down via dst_dev_put()/free_netdev(), which a remote attacker cannot induce or time.\nPR:N - The CLC handshake is the first exchange on the connection and SMC performs no authentication before smc_clc_prfx_match() runs, so an unauthenticated remote attacker reaches the bug with no credentials of any kind.\nUI:N - Triggering requires only that the attacker complete a TCP handshake with the SMC option and send a CLC Proposal; no action by any local user or administrator is needed.\nS:U - The use-after-free is confined to kernel memory (the net_device slab and the in_dev/inet6_dev structures it points at) within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed net_device is dereferenced and its ifa_list/addr_list walked, and since a reclaimed slab can be groomed with attacker-controlled data this yields an arbitrary kernel-memory read primitive; the match/no-match outcome is additionally returned to the peer as SMC_CLC_DECL_DIFFPREFIX, forming a remotely observable oracle on freed memory contents.\nI:H - A use-after-free of a net_device is a heap-corruption primitive: the reclaimed object's contents are attacker-influencable via heap spraying and the code follows pointers out of it, which can be groomed into an arbitrary write and control-flow hijack.\nA:H - Dereferencing the freed net_device and walking a bogus in_dev/inet6_dev address list reliably produces a kernel oops, panic, or an unbounded list walk, crashing the system."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/smc/smc_clc.c"
                    ],
                    "versions": [
                        {
                            "version": "a046d57da19f812216f393e7c535f5858f793ac3",
                            "lessThan": "d26e80f7fb62d77757b67a1b94e4ac756bc9c658",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "a046d57da19f812216f393e7c535f5858f793ac3",
                            "lessThan": "235f81045c008169cc4e1955b4a64e118eebe61b",
                            "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/smc/smc_clc.c"
                    ],
                    "versions": [
                        {
                            "version": "4.11",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.11",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.17.3",
                            "lessThanOrEqual": "6.17.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18",
                            "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": "4.11",
                                    "versionEndExcluding": "6.17.3"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.11",
                                    "versionEndExcluding": "6.18"
                                }
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            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/d26e80f7fb62d77757b67a1b94e4ac756bc9c658"
                },
                {
                    "url": "https://git.kernel.org/stable/c/235f81045c008169cc4e1955b4a64e118eebe61b"
                }
            ],
            "title": "smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match().",
            "x_generator": {
                "engine": "bippy-1.2.0"
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        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-06-16T19:59:59.004592Z",
                                "id": "CVE-2025-40168",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
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                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
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                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-06-16T20:00:14.873Z"
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}