CVE-2025-21657

Summary

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 =====

Affected Software

VendorProductVersion RangeStatus
LinuxLinux0e7ffff1b8117b05635c87d3c9099f6aa9c9b689 < d9e446dd63cee7161717a6a8414ba9c6435af764affected
LinuxLinux0e7ffff1b8117b05635c87d3c9099f6aa9c9b689 < 6268d5bc10354fc2ab8d44a0cd3b042d49a0417eaffected
LinuxLinux6.12affected
LinuxLinux0 < 6.12unaffected
LinuxLinux6.12.10 <= 6.12.*unaffected
LinuxLinux6.13 <= *unaffected

Weaknesses

References