{"id":"CVE-2026-43438","summary":"sched_ext: Remove redundant css_put() in scx_cgroup_init()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Remove redundant css_put() in scx_cgroup_init()\n\nThe iterator css_for_each_descendant_pre() walks the cgroup hierarchy\nunder cgroup_lock(). It does not increment the reference counts on\nyielded css structs.\n\nAccording to the cgroup documentation, css_put() should only be used\nto release a reference obtained via css_get() or css_tryget_online().\nSince the iterator does not use either of these to acquire a reference,\ncalling css_put() in the error path of scx_cgroup_init() causes a\nrefcount underflow.\n\nRemove the unbalanced css_put() to prevent a potential Use-After-Free\n(UAF) vulnerability.","modified":"2026-07-15T01:49:01.899309908Z","published":"2026-05-08T14:22:07.980Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43438.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1336b579f6079fb8520be03624fcd9ba443c930b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6eaaa67d6998f6c30c462b140db8c062e07ec473"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bf50f3285eda8a0173625fcdb5f183f96e1008cd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cc095cd305fddbe25a968e4a78436ff9476cf0f6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43438.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43438"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8195136669661fdfe54e9a8923c33b31c92fc1da"},{"fixed":"cc095cd305fddbe25a968e4a78436ff9476cf0f6"},{"fixed":"6eaaa67d6998f6c30c462b140db8c062e07ec473"},{"fixed":"bf50f3285eda8a0173625fcdb5f183f96e1008cd"},{"fixed":"1336b579f6079fb8520be03624fcd9ba443c930b"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43438.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.12.0"},{"fixed":"6.12.78"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.19"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43438.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}