SB20260529134 - Use-after-free in Linux kernel sched

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-46154)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to use-after-free in scx_group_set_{weight,idle,bandwidth}() and sched_ext cgroup setters when racing scheduler disable and enable operations while handling cgroup setting changes. A local user can trigger concurrent cgroup setter activity to dereference a freed scheduler pointer and cause a denial of service.

The issue occurs because a cached scx_root pointer can become stale before scx_cgroup_ops_rwsem is acquired.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0f54f6355575971673d8aac7da107ec4178e45bd
• https://git.kernel.org/stable/c/80afd4c84bc8f5e80145ce35279f5ce53f6043db
• https://git.kernel.org/stable/c/ce9aaa3af445c391735c9d000c4db60dfd5640d4