{"id":"CVE-2026-23270","revision":"db8fb03d01dc4f1f8e19b9f6da3c89ee","records":[{"revision":"db8fb03d01dc4f1f8e19b9f6da3c89ee","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-23270","aliases":[],"title":"net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks\n\nAs Paolo said earlier [1]:\n\n\"Since the blamed commit below, classify can return TC_ACT_CONSUMED while\nthe current skb being held by the defragmentation engine. As reported by\nGangMin Kim, if such packet is that may cause a UaF when the defrag engine\nlater on tries to tuch again such packet.\"\n\nact_ct was never meant to be used in the egress path, however some users\nare attaching it to egress today [2]. Attempting to reach a middle\nground, we noticed that, while most qdiscs are not handling\nTC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we\naddress the issue by only allowing act_ct to bind to clsact/ingress\nqdiscs and shared blocks. That way it's still possible to attach act_ct to\negress (albeit only with clsact).\n\n[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/\n[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/","state":0,"publishedAt":"2026-03-18T17:54:43.803+00:00","modifiedAt":"2026-10-19T18:35:40.58+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/act_api.h\",\n                        \"net/sched/act_ct.c\",\n                        \"net/sched/cls_api.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"172ba7d46c202e679f3ccb10264c67416aaeb1c4\",\n                            \"lessThan\": \"bc4e5bb529823a09f02dbe96169de679a9db26e0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0b5b831122fc3789fff75be433ba3e4dd7b779d4\",\n                            \"lessThan\": \"fb3c380a54e33d1fd272cc342faa906d787d7ef1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"73f7da5fd124f2cda9161e2e46114915e6e82e97\",\n                            \"lessThan\": \"5a110ddcc99bda77a28598b3555fe009eaab3828\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f14b377d01d8357eba032b4cabc8c1149b458b6\",\n                            \"lessThan\": \"524ce8b4ea8f64900b6c52b6a28df74f6bc0801e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f14b377d01d8357eba032b4cabc8c1149b458b6\",\n                            \"lessThan\": \"380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f14b377d01d8357eba032b4cabc8c1149b458b6\",\n                            \"lessThan\": \"9deda0fcda5c1f388c5e279541850b71a2ccfcf4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f14b377d01d8357eba032b4cabc8c1149b458b6\",\n                            \"lessThan\": \"11cb63b0d1a0685e0831ae3c77223e002ef18189\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f5346df0591d10bc948761ca854b1fae6d2ef441\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5.15.148\",\n                            \"lessThan\": \"5.15.203\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.75\",\n                            \"lessThan\": \"6.1.167\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.14\",\n                            \"lessThan\": \"6.6.130\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.7.2\",\n                            \"lessThan\": \"6.8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\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/act_api.h\",\n                        \"net/sched/act_ct.c\",\n                        \"net/sched/cls_api.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.8\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.8\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.203\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.167\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.130\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.77\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.18\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.8\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0\",\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/bc4e5bb529823a09f02dbe96169de679a9db26e0","https://git.kernel.org/stable/c/fb3c380a54e33d1fd272cc342faa906d787d7ef1","https://git.kernel.org/stable/c/5a110ddcc99bda77a28598b3555fe009eaab3828","https://git.kernel.org/stable/c/524ce8b4ea8f64900b6c52b6a28df74f6bc0801e","https://git.kernel.org/stable/c/380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6","https://git.kernel.org/stable/c/9deda0fcda5c1f388c5e279541850b71a2ccfcf4","https://git.kernel.org/stable/c/11cb63b0d1a0685e0831ae3c77223e002ef18189"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23270","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-23270","identifiers":["CVE-2026-23270"]},"retained":false,"historicalAffected":[]}],"coverage":[]}