CVE-2025-38522 Information

Aug 17, 2025 cve

Description

In the Linux kernel the following vulnerability has been resolved:

sched/ext: Prevent update_locked_rq() calls with NULL rq

Avoid invoking update_locked_rq() when the runqueue (rq) pointer is NULL in the SCX_CALL_OP and SCX_CALL_OP_RET macros.

Previously calling update_locked_rq(NULL) with preemption enabled could trigger the following warning:

BUG: using __this_cpu_write() in preemptible [00000000]

This happens because __this_cpu_write() is unsafe to use in preemptible context.

rq is NULL when an ops invoked from an unlocked context. In such cases we don’t need to store any rq since the value should already be NULL (unlocked). Ensure that update_locked_rq() is only called when rq is non-NULL preventing calling __this_cpu_write() on preemptible context.

Reference

https://git.kernel.org/stable/c/237c43037b336e36a49eb9f2daac1c7719ec7f8b https://git.kernel.org/stable/c/e14fd98c6d66cb76694b12c05768e4f9e8c95664

CNNVD-202508-1941 (Published: 2025-08-16)

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