Vulnerability in Linux
CVE-2025-21657
In the Linux kernel, the following vulnerability has been resolved: sched_ext: Replace rq_lock() to raw_spin_rq_lock() in scx_ops_bypass() scx_ops_bypass() iterates all CPUs to re-enqueue all the scx tasks. For each CPU, it acquires a lock using rq_lock() regardless of whether a CPU is offline or the CPU is currently running a task in a higher scheduler class (e.g., deadline). The rq_lock() is supposed to be used for online CPUs, and the use of rq_lock() may trigger an unnecessary warning in rq_pin_lock(). Therefore, replace rq_lock() to raw_spin_rq_lock() in scx_ops_bypass(). Without this change, we observe the following warning: ===== START ===== [ 6.615205] rq->balance_callback && rq->balance_callback != &balance_push_callback [ 6.615208] WARNING: CPU: 2 PID: 0 at kernel/sched/sched.h:1730 __schedule+0x1130/0x1c90 ===== END =====
EPSS: 0.002 (6.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Linux — versions 0e7ffff1b8117b05635c87d3c9099f6aa9c9b689, 6.12, 0
- Linux Linux_kernel — versions 6.12, 6.13
References
Frequently asked questions
- What is CVE-2025-21657?
- CVE-2025-21657 is a medium-severity vulnerability in Linux. CVSS score: 5.5/10. Published 2025-01-21.
- How severe is CVE-2025-21657?
- Medium severity. CVSS v3 base score is 5.5 out of 10.