{"id":"CVE-2026-23413","revision":"3d39fce4f4d64ecea4d89b7b455b0062","records":[{"revision":"3d39fce4f4d64ecea4d89b7b455b0062","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-23413","aliases":[],"title":"clsact: Fix use-after-free in init/destroy rollback asymmetry","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nclsact: Fix use-after-free in init/destroy rollback asymmetry\n\nFix a use-after-free in the clsact qdisc upon init/destroy rollback asymmetry.\nThe latter is achieved by first fully initializing a clsact instance, and\nthen in a second step having a replacement failure for the new clsact qdisc\ninstance. clsact_init() initializes ingress first and then takes care of the\negress part. This can fail midway, for example, via tcf_block_get_ext(). Upon\nfailure, the kernel will trigger the clsact_destroy() callback.\n\nCommit 1cb6f0bae504 (\"bpf: Fix too early release of tcx_entry\") details the\nway how the transition is happening. If tcf_block_get_ext on the q->ingress_block\nends up failing, we took the tcx_miniq_inc reference count on the ingress\nside, but not yet on the egress side. clsact_destroy() tests whether the\n{ingress,egress}_entry was non-NULL. However, even in midway failure on the\nreplacement, both are in fact non-NULL with a valid egress_entry from the\nprevious clsact instance.\n\nWhat we really need to test for is whether the qdisc instance-specific ingress\nor egress side previously got initialized. This adds a small helper for checking\nthe miniq initialization called mini_qdisc_pair_inited, and utilizes that upon\nclsact_destroy() in order to fix the use-after-free scenario. Convert the\ningress_destroy() side as well so both are consistent to each other.","state":0,"publishedAt":"2026-04-02T11:40:54.384+00:00","modifiedAt":"2026-10-19T18:35:42.855+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/sch_generic.h\",\n                        \"net/sched/sch_ingress.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"230bb13650b0f186f540500fd5f5f7096a822a2a\",\n                            \"lessThan\": \"a73d95b57bf9faebdfed591bcb7ed9292062a84c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1cb6f0bae50441f4b4b32a28315853b279c7404e\",\n                            \"lessThan\": \"37bef86e5428d59f70a4da82b80f9a8f252fecbe\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1cb6f0bae50441f4b4b32a28315853b279c7404e\",\n                            \"lessThan\": \"4c9af67f99aa3e51b522c54968ab3ac8272be41c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1cb6f0bae50441f4b4b32a28315853b279c7404e\",\n                            \"lessThan\": \"0509b762bc5e8ea7b8391130730c6d8502fc6e69\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"1cb6f0bae50441f4b4b32a28315853b279c7404e\",\n                            \"lessThan\": \"a0671125d4f55e1e98d9bde8a0b671941987e208\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f61ecf1bd5b562ebfd7d430ccb31619857e80857\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6.6.41\",\n                            \"lessThan\": \"6.6.130\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.9.10\",\n                            \"lessThan\": \"6.10\",\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/sch_generic.h\",\n                        \"net/sched/sch_ingress.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.10\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.10\",\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\": \"6.12.78\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.20\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.10\",\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/a73d95b57bf9faebdfed591bcb7ed9292062a84c","https://git.kernel.org/stable/c/37bef86e5428d59f70a4da82b80f9a8f252fecbe","https://git.kernel.org/stable/c/4c9af67f99aa3e51b522c54968ab3ac8272be41c","https://git.kernel.org/stable/c/0509b762bc5e8ea7b8391130730c6d8502fc6e69","https://git.kernel.org/stable/c/a0671125d4f55e1e98d9bde8a0b671941987e208"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23413","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-23413","identifiers":["CVE-2026-23413"]},"retained":false,"historicalAffected":[]}],"coverage":[]}