{"id":"CVE-2026-98303","revision":"d966e08b2b4f422384755067cfe92137","records":[{"revision":"d966e08b2b4f422384755067cfe92137","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98303","aliases":[],"title":"ipv4: icmp: reject RTN_UNREACHABLE input routes in icmp_route_lookup","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: icmp: reject RTN_UNREACHABLE input routes in icmp_route_lookup\n\nWhen the forward output route cannot be used in icmp_route_lookup(),\nit enters the \"reverse path\" and calls ip_route_input() on fl4_dec.daddr,\nthe original packet's source address.\n\nip_route_input() only returns an error for truly invalid packets. For\nunreachable addresses it will succeed and return an input route whose\ndst.output is set to ip_rt_bug(). The existing check only rejects\nRTN_LOCAL routes, so the RTN_UNREACHABLE route types can still be returned\nand later used for output, syzkaller triggering a WARN_ON_ONCE()\nin ip_rt_bug() as bellow:\n\n ------------[ cut here ]------------\n WARNING: net/ipv4/route.c:1273 at ip_rt_bug+0x14/0x20\n RIP: 0010:ip_rt_bug+0x14/0x20\n Call Trace:\n  ip_push_pending_frames+0xfa/0x100\n  __icmp_send+0x905/0xf10\n  ip_options_compile+0xc0/0xd0\n  ip_rcv_finish_core+0x321/0xae0\n  ip_rcv+0x1de/0x260\n  __netif_receive_skb_one_core+0x11a/0x130\n  netif_receive_skb+0x7b/0x260\n  tun_get_user+0x11bf/0x1c10\n ------------[ cut here ]------------\n\nReject input route that is RTN_UNREACHABLE to fix it. The net warning\nis only printed for RTN_LOCAL, as RTN_UNREACHABLE is not the result of\na race condition.","state":0,"publishedAt":"2026-10-06T08:46:00.524+00:00","modifiedAt":"2026-10-19T09:17:14.136+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/icmp.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"06083cea4a3b95f5ebc85312f97d7086e6c9e782\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"83aa83f81a8fec30ff5372dee60b2f0561bcb2ca\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"cac69c50716c712ef0114837c9427da66066124c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"1af2d87964d87ba7626d96928d68c09158b5a223\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"fda3000147dc96c75ba162f680bec0a9fecf3037\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"8b7817f3a959ed99d7443afc12f78a7e1fcc2063\",\n                            \"lessThan\": \"2998147b59c9df0a51477c7a6b3d1f0ba3127dd4\",\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/icmp.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2.6.25\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"2.6.25\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.189\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.112\",\n                            \"lessThanOrEqual\": \"6.12.*\",\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/06083cea4a3b95f5ebc85312f97d7086e6c9e782","https://git.kernel.org/stable/c/83aa83f81a8fec30ff5372dee60b2f0561bcb2ca","https://git.kernel.org/stable/c/cac69c50716c712ef0114837c9427da66066124c","https://git.kernel.org/stable/c/1af2d87964d87ba7626d96928d68c09158b5a223","https://git.kernel.org/stable/c/fda3000147dc96c75ba162f680bec0a9fecf3037","https://git.kernel.org/stable/c/2998147b59c9df0a51477c7a6b3d1f0ba3127dd4"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98303","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98303","identifiers":["CVE-2026-98303"]},"retained":false,"historicalAffected":[]}],"coverage":[]}