CVE-2023-53656: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53656 is a vulnerability discovered in the Linux kernel's performance monitoring subsystem, specifically affecting the HiSilicon PCIe PMU driver. The vulnerability was published on October 7, 2025, and involves an issue with CPU migration during teardown operations (NVD).

The vulnerability occurs in the drivers/perf component when migrating perf context during CPU teardown. The issue arises because the cpuonlinemask() hasn't been updated when calling the cpuhp::teardown() callback, which can lead to migrating the context to a CPU that is being torn down. The fix involves using the cpumaskanybut() function to identify a correct active CPU (RedHat). The vulnerability has been assigned a CVSS 3.1 base score of 5.5 with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (RedHat).

The vulnerability can result in a system deadlock condition when the performance monitoring context is incorrectly migrated to a CPU that is being torn down. This can lead to availability issues in affected systems, as evidenced by the reported call trace showing a task entering an uninterruptible sleep state (NVD).

The vulnerability has been resolved in the Linux kernel by implementing a fix that uses the cpumaskanybut() function to correctly identify an active CPU during context migration. System administrators should apply the appropriate kernel updates when available (NVD).