{"id":"CVE-2026-98240","revision":"e548b07e82b54d0eb56b909db72664c3","records":[{"revision":"e548b07e82b54d0eb56b909db72664c3","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98240","aliases":[],"title":"net: ip_tunnel: initialize `options_len` before referencing options","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ip_tunnel: initialize `options_len` before referencing options\n\nThe following command triggers a kernel panic:\n\n  ip link add d0 type dummy; ip link set d0 up\n  ip route add 10.30.0.0/16 \\\n    encap ip id 300 geneve_opts 4660:66:11223344 dev d0\n\n  memcpy: detected buffer overflow: 4 byte write of buffer size 0\n  kernel BUG at lib/string_helpers.c:1044!\n  ...\n  ip_tun_parse_opts.part.0.cold+0x10/0x10\n  ip_tun_build_state+0x116/0x2a0\n\nOn kernels built with GCC 15+ and `CONFIG_FORTIFY_SOURCE`, the fortified\n`memcpy()` got 0 sized destination with request of 4 bytes length:\n\n  static int ip_tun_parse_opts_geneve(...)\n  {\n      ...\n      attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA];\n      data_len = nla_len(attr); /* == 4 */\n\n      struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;\n      memcpy(opt->opt_data, nla_data(attr), data_len);\n      /*     ^^^^^^^^^^^^^ 0 since options_len is assigned afterwards */\n\nFixed by initializing the counter before the options are referenced.\nMatching what `tunnel_key_opts_set()` already does.","state":0,"publishedAt":"2026-10-06T08:45:11.284+00:00","modifiedAt":"2026-10-19T09:16:11.863+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                        \"net/ipv4/ip_tunnel_core.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"bb5e62f2d547c4de6d1b144cbce2373a76c33f18\",\n                            \"lessThan\": \"9907325257b4b382f26aafd5d9a8d47915907dd5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bb5e62f2d547c4de6d1b144cbce2373a76c33f18\",\n                            \"lessThan\": \"0f6a6beb01c068fcd5274eabf22c260039749fea\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"bb5e62f2d547c4de6d1b144cbce2373a76c33f18\",\n                            \"lessThan\": \"455ebeadf714f51e1dbbd6a022c74c9215b1cd76\",\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                        \"net/ipv4/ip_tunnel_core.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.15\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.15\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.54\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.8\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/9907325257b4b382f26aafd5d9a8d47915907dd5","https://git.kernel.org/stable/c/0f6a6beb01c068fcd5274eabf22c260039749fea","https://git.kernel.org/stable/c/455ebeadf714f51e1dbbd6a022c74c9215b1cd76"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98240","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98240","identifiers":["CVE-2026-98240"]},"retained":false,"historicalAffected":[]}],"coverage":[]}