UBSAN Shift-Out-of-Bounds Vulnerability in Linux Kernel

CVE-2025-21815

Summary

A vulnerability in the Linux kernel's memory management subsystem was identified, causing a UBSAN shift-out-of-bounds warning triggered in the isolate_freepages_block function. The issue arose from improper handling of the compound_order variable which could take on unexpected values. A MAX_PAGE_ORDER check was added to mitigate this issue, ensuring proper functionality and reducing the risk of exploitable conditions in memory management.

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