{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-74543",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-15T05:44:03.914Z",
        "datePublished": "2026-08-15T12:27:53.336Z",
        "dateUpdated": "2026-08-17T05:21:28.314Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-17T05:21:28.314Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: udp_tunnel: fix memory leak in udp_tunnel_nic_unregister()\n\nsyzbot reported a memory leak [1] in the UDP tunnel NIC offload code.\n\nWhen device registration fails (e.g. in register_netdevice()), netdev core\nunwinds by sending a single NETDEV_UNREGISTER notification. If work was queued\nduring NETDEV_REGISTER (utn->work_pending is set), udp_tunnel_nic_unregister()\nreturns early:\n\n\tif (utn->work_pending)\n\t\treturn;\n\nBecause failed registrations do not enter netdev_wait_allrefs_any(), no\nsubsequent NETDEV_UNREGISTER rebroadcast will ever occur. As a result, the\nstruct udp_tunnel_nic allocated in udp_tunnel_nic_alloc() is leaked\npermanently.\n\nFix this by removing the early return. Instead, synchronously cancel any\npending work with cancel_delayed_work_sync() before freeing @utn.\n\nTo be able to call cancel_delayed_work_sync() while holding RTNL (the work also\nneeds RTNL), switch udp_tunnel_nic_device_sync_work() to rtnl_trylock(). If RTNL\nis contended, requeue the work with a 1 jiffy delay (via queue_delayed_work())\nto prevent high CPU contention while waiting for RTNL lock.\n\nThe utn->work_pending bookkeeping is no longer needed and is removed, as\nthe workqueue core already tracks the pending/running state of the work.\n\n[1]\nBUG: memory leak\nunreferenced object 0xffff888127d5f840 (size 96):\n  comm \"syz-executor\", pid 5806, jiffies 4294942188\n  backtrace (crc 99fdb6c8):\n    __kmalloc_noprof+0x3bf/0x550\n    udp_tunnel_nic_alloc net/ipv4/udp_tunnel_nic.c:756 [inline]\n    udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:833 [inline]\n    udp_tunnel_nic_netdevice_event+0x804/0xab0 net/ipv4/udp_tunnel_nic.c:931\n    notifier_call_chain+0x59/0x160 kernel/notifier.c:85\n    call_netdevice_notifiers_info+0x7d/0xb0 net/core/dev.c:2250\n    register_netdevice+0xc10/0xeb0 net/core/dev.c:11478"
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/ipv4/udp_tunnel_nic.c"
                    ],
                    "versions": [
                        {
                            "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
                            "lessThan": "b712da45bd9b9835d132e9fbc0c3e43c164cb1fd",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
                            "lessThan": "f82a2ded3d7a9098267c84f14eafdb98c4550ac5",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
                            "lessThan": "b322532a4b774db1b480a2de84125910a70739a5",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "cc4e3835eff474aa274d6e1d18f69d9d296d3b76",
                            "lessThan": "080695e6f005e2396f1207fd69d24c442cb230c6",
                            "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/udp_tunnel_nic.c"
                    ],
                    "versions": [
                        {
                            "version": "5.9",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.9",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.103",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.44",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.8",
                            "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": "5.9",
                                    "versionEndExcluding": "6.12.103"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.9",
                                    "versionEndExcluding": "6.18.44"
                                },
                                {
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.9",
                                    "versionEndExcluding": "7.1.8"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.9",
                                    "versionEndExcluding": "7.2"
                                }
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            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/b712da45bd9b9835d132e9fbc0c3e43c164cb1fd"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f82a2ded3d7a9098267c84f14eafdb98c4550ac5"
                },
                {
                    "url": "https://git.kernel.org/stable/c/b322532a4b774db1b480a2de84125910a70739a5"
                },
                {
                    "url": "https://git.kernel.org/stable/c/080695e6f005e2396f1207fd69d24c442cb230c6"
                }
            ],
            "title": "net: udp_tunnel: fix memory leak in udp_tunnel_nic_unregister()",
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