{"id":"CVE-2026-72427","revision":"fe508ca5bca54cda8f2f68274ce04db5","records":[{"revision":"fe508ca5bca54cda8f2f68274ce04db5","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-72427","aliases":[],"title":"bpf: Fix effective prog array index with BPF_F_PREORDER","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix effective prog array index with BPF_F_PREORDER\n\nreplace_effective_prog() and purge_effective_progs() located the slot in\nthe effective array by walking the program hlist and counting entries\nlinearly. That count does not match the array layout: compute_effective_\nprogs() places BPF_F_PREORDER programs at the front (ancestor cgroup\nfirst, attach order within a cgroup) and the rest after them (descendant\ncgroup first). So when a preorder program is present, the linear hlist\nposition no longer equals the program's index in the effective array.\n\nFor replace_effective_prog() (bpf_link_update()) this overwrote the\nwrong slot, corrupting the effective order. For purge_effective_progs(),\nit could dummy out a slot belonging to a different program and leave the\ndetached program in the array while bpf_prog_put() drops its reference,\ni.e. a use-after-free.\n\nFix both by replaying compute_effective_progs()'s placement (including\nthe per-cgroup preorder reversal) in a shared effective_prog_pos()\nhelper. Identify the entry by its struct bpf_prog_list pointer rather\nthan by (prog, link) value, so the lookup resolves to exactly the\nattachment the syscall selected even when the same bpf_prog is attached\nto several cgroups in the hierarchy.","state":0,"publishedAt":"2026-08-15T05:56:44.197+00:00","modifiedAt":"2026-10-16T18:55:23.555+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                        \"kernel/bpf/cgroup.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"bc8023ef3b11410682e5d4990e05e5bc2d3e1c94\",\n                            \"lessThan\": \"525e408c27ae714e538b8c608c3a974df3ab6c92\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"555c0b713ca83968d3c843cb15485b9ba3367b1b\",\n                            \"lessThan\": \"41b4320b84fdafe1ab586b06453d30d50415db59\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4b82b181a26cff8bf7adc3a85a88d121d92edeaf\",\n                            \"lessThan\": \"9697db03e010391c55ae75192cbdf30c5a72c114\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4b82b181a26cff8bf7adc3a85a88d121d92edeaf\",\n                            \"lessThan\": \"b584f107ab90222bd825dcb4c5977326ff684109\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4b82b181a26cff8bf7adc3a85a88d121d92edeaf\",\n                            \"lessThan\": \"f08aaee3152d0dfc578b3f2586932d82062701dd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4707ad649cf662add3058bff47430817811b048d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6.6.93\",\n                            \"lessThan\": \"6.6.145\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.31\",\n                            \"lessThan\": \"6.12.97\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.14.9\",\n                            \"lessThan\": \"6.15\",\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                        \"kernel/bpf/cgroup.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\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.40\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.5\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\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/525e408c27ae714e538b8c608c3a974df3ab6c92","https://git.kernel.org/stable/c/41b4320b84fdafe1ab586b06453d30d50415db59","https://git.kernel.org/stable/c/9697db03e010391c55ae75192cbdf30c5a72c114","https://git.kernel.org/stable/c/b584f107ab90222bd825dcb4c5977326ff684109","https://git.kernel.org/stable/c/f08aaee3152d0dfc578b3f2586932d82062701dd"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72427","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-72427","identifiers":["CVE-2026-72427"]},"retained":false,"historicalAffected":[]}],"coverage":[]}