{"id":"CVE-2025-40173","revision":"134183fa279043a68be0d38aa7d32441","records":[{"revision":"134183fa279043a68be0d38aa7d32441","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2025-40173","aliases":[],"title":"net/ip6_tunnel: Prevent perpetual tunnel growth","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/ip6_tunnel: Prevent perpetual tunnel growth\n\nSimilarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too.\nWhile ipv4 tunnel headroom adjustment growth was limited in\ncommit 5ae1e9922bbd (\"net: ip_tunnel: prevent perpetual headroom growth\"),\nipv6 tunnel yet increases the headroom without any ceiling.\n\nReflect ipv4 tunnel headroom adjustment limit on ipv6 version.\n\nCredits to Francesco Ruggeri, who was originally debugging this issue\nand wrote local Arista-specific patch and a reproducer.","state":0,"publishedAt":"2025-11-12T10:53:49.571+00:00","modifiedAt":"2026-10-15T22:02:39.584+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/net/ip_tunnels.h\",\n                        \"net/ipv4/ip_tunnel.c\",\n                        \"net/ipv6/ip6_tunnel.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"8eb30be0352d09165e94a41fef1c7b994dca0714\",\n                            \"lessThan\": \"566f8d5c8a443f2dd69c5460fdec43ed1c870c65\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8eb30be0352d09165e94a41fef1c7b994dca0714\",\n                            \"lessThan\": \"11f6066af3bfb8149aa16c42c0b0c5ea5b199a94\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8eb30be0352d09165e94a41fef1c7b994dca0714\",\n                            \"lessThan\": \"402b6985e872b4cf394bbbf33b503947a326a6cb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8eb30be0352d09165e94a41fef1c7b994dca0714\",\n                            \"lessThan\": \"10fe967efe73c610e526ff7460581610633dee9c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8eb30be0352d09165e94a41fef1c7b994dca0714\",\n                            \"lessThan\": \"48294a67863c9cfa367abb66bbf0ef6548ae124f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8eb30be0352d09165e94a41fef1c7b994dca0714\",\n                            \"lessThan\": \"eeb4345488672584db4f8c20a1ae13a212ce31c4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8eb30be0352d09165e94a41fef1c7b994dca0714\",\n                            \"lessThan\": \"b6eb25d870f1a8ae571fd3da2244b71df547824b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8eb30be0352d09165e94a41fef1c7b994dca0714\",\n                            \"lessThan\": \"21f4d45eba0b2dcae5dbc9e5e0ad08735c993f16\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"include/net/ip_tunnels.h\",\n                        \"net/ipv4/ip_tunnel.c\",\n                        \"net/ipv6/ip6_tunnel.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.7\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.7\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.4.301\",\n                            \"lessThanOrEqual\": \"5.4.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.246\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.196\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.158\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.114\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.55\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.17.5\",\n                            \"lessThanOrEqual\": \"6.17.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/566f8d5c8a443f2dd69c5460fdec43ed1c870c65","https://git.kernel.org/stable/c/11f6066af3bfb8149aa16c42c0b0c5ea5b199a94","https://git.kernel.org/stable/c/402b6985e872b4cf394bbbf33b503947a326a6cb","https://git.kernel.org/stable/c/10fe967efe73c610e526ff7460581610633dee9c","https://git.kernel.org/stable/c/48294a67863c9cfa367abb66bbf0ef6548ae124f","https://git.kernel.org/stable/c/eeb4345488672584db4f8c20a1ae13a212ce31c4","https://git.kernel.org/stable/c/b6eb25d870f1a8ae571fd3da2244b71df547824b","https://git.kernel.org/stable/c/21f4d45eba0b2dcae5dbc9e5e0ad08735c993f16"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-40173","license":"CVE Program Terms of Use","key":"cve-program:CVE-2025-40173","identifiers":["CVE-2025-40173"]},"retained":false,"historicalAffected":[]}],"coverage":[]}