SB20260502104 - Always-Incorrect Control Flow Implementation in Linux kernel sched

Description

This security bulletin contains information about 1 vulnerability.

1) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-31734)

CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/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 improper state handling in is_bpf_migration_disabled() when checking whether a task is migration-disabled on systems without CONFIG_PREEMPT_RCU. A local user can trigger task dispatch to a remote CPU for a migration-disabled task to cause a denial of service.

The issue can trigger scx_error in task_can_run_on_remote_rq().

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0c4a59df370bea245695c00aaae6ae75747139bd
• https://git.kernel.org/stable/c/72c43eb2e334febe93018cfb68ae828f55c6e49e
• https://git.kernel.org/stable/c/b4992a9446bb9a639007bfd32bf5c5a7e30199e5