{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-68296",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-30T09:28:09.380Z",
        "datePublished": "2026-08-10T12:02:29.464Z",
        "dateUpdated": "2026-08-17T05:02:32.404Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-17T05:02:32.404Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gre: fix lltx regression for GRE tunnels with SEQ/CSUM\n\nBefore commit 00d066a4d4ed (\"netdev_features: convert NETIF_F_LLTX to\ndev->lltx\"), NETIF_F_LLTX was set unconditionally in both\n__gre_tunnel_init() and ip6gre_tnl_init_features() alongside\nGRE_FEATURES:\n\n    dev->features |= GRE_FEATURES | NETIF_F_LLTX;\n\nWhen that commit converted NETIF_F_LLTX to the dev->lltx flag, it\nplaced 'dev->lltx = true' after the SEQ/CSUM early returns instead\nof before them. This causes GRE/GRETAP/ip6gre tunnels with SEQ or\nCSUM+encap to lose lockless TX, reintroducing _xmit_lock acquisition\naround their ndo_start_xmit. Since GRE xmit re-enters the stack via\nip_tunnel_xmit(), holding _xmit_lock risks ABBA deadlock with the\nunderlay device.\n\n  CPU0                        CPU1\n  ----                        ----\n  lock(&qdisc_xmit_lock_key#6);\n                              lock(&qdisc_xmit_lock_key#3);\n                              lock(&qdisc_xmit_lock_key#6);\n  lock(&qdisc_xmit_lock_key#3);\n\nFix by moving dev->lltx = true before the early returns in both\nfunctions, restoring the original unconditional behavior."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/ip_gre.c",
                        "net/ipv6/ip6_gre.c"
                    ],
                    "versions": [
                        {
                            "version": "00d066a4d4edbe559ba6c35153da71d4b2b8a383",
                            "lessThan": "9f948e9aede9678f4103457daf2bc9dd54c65a06",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "00d066a4d4edbe559ba6c35153da71d4b2b8a383",
                            "lessThan": "15a1c5f2ed2eeb3daad8d5766fd506aeda4710f3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "00d066a4d4edbe559ba6c35153da71d4b2b8a383",
                            "lessThan": "2bffe379023512d280337c70faeb6a8cc435db5e",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "00d066a4d4edbe559ba6c35153da71d4b2b8a383",
                            "lessThan": "675ed582c1aa4d919dd535490de08c015005c653",
                            "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/ipv4/ip_gre.c",
                        "net/ipv6/ip6_gre.c"
                    ],
                    "versions": [
                        {
                            "version": "6.12",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.12",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.101",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.42",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.6",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "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": "6.12.101"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.12",
                                    "versionEndExcluding": "6.18.42"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.12",
                                    "versionEndExcluding": "7.1.6"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.12",
                                    "versionEndExcluding": "7.2"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/9f948e9aede9678f4103457daf2bc9dd54c65a06"
                },
                {
                    "url": "https://git.kernel.org/stable/c/15a1c5f2ed2eeb3daad8d5766fd506aeda4710f3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/2bffe379023512d280337c70faeb6a8cc435db5e"
                },
                {
                    "url": "https://git.kernel.org/stable/c/675ed582c1aa4d919dd535490de08c015005c653"
                }
            ],
            "title": "net: gre: fix lltx regression for GRE tunnels with SEQ/CSUM",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}