CVE-2026-43438

HIGH

sched_ext: Remove redundant css_put() in scx_cgroup_init()

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Remove redundant css_put() in scx_cgroup_init() The iterator css_for_each_descendant_pre() walks the cgroup hierarchy under cgroup_lock(). It does not increment the reference counts on yielded css structs. According to the cgroup documentation, css_put() should only be used to release a reference obtained via css_get() or css_tryget_online(). Since the iterator does not use either of these to acquire a reference, calling css_put() in the error path of scx_cgroup_init() causes a refcount underflow. Remove the unbalanced css_put() to prevent a potential Use-After-Free (UAF) vulnerability.

Scores

CVSS v3 7.8
EPSS 0.0001
EPSS Percentile 2.5%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-416
Status published
Products (12)
Linux/Linux < 6.12
Linux/Linux 6.12
Linux/Linux 6.12.78 - 6.12.*
Linux/Linux 6.18.19 - 6.18.*
Linux/Linux 6.19.9 - 6.19.*
Linux/Linux 7.0
Linux/Linux 8195136669661fdfe54e9a8923c33b31c92fc1da - 1336b579f6079fb8520be03624fcd9ba443c930b
Linux/Linux 8195136669661fdfe54e9a8923c33b31c92fc1da - 6eaaa67d6998f6c30c462b140db8c062e07ec473
Linux/Linux 8195136669661fdfe54e9a8923c33b31c92fc1da - bf50f3285eda8a0173625fcdb5f183f96e1008cd
Linux/Linux 8195136669661fdfe54e9a8923c33b31c92fc1da - cc095cd305fddbe25a968e4a78436ff9476cf0f6
... and 2 more
Published May 08, 2026
Tracked Since May 08, 2026