CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's handling of page table mappings, specifically allowing unprivileged processes to manipulate zero mappings, which can lead to an overflow of the file_map_count and trigger a critical error. This could potentially enable attackers to exploit system resources, leading to denial of service or instability in affected systems. System administrators and security teams managing Linux environments should prioritize addressing this issue to mitigate risks associated with unauthorized access and system reliability.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: mm/page_table_check: skip special zero mappings page_table_check_set() and page_table_check_clear() account mappings based on PageAnon(). Shared zero-page PTEs and huge zero PMDs are special mappings, but page_table_check can still account them as file-backed pages. An unprivileged process can populate enough zero mappings to overflow file_map_count and hit the existing BUG_ON(). The PTE path can do this with the shared zero page, and the PMD path can do the same with huge zero mappings. Skip special zero mappings in the user page-table accounting paths. Keep the PTE-side pte_special() check, and identify huge zero PMDs from the mapped folio instead of pmd_special(). That covers architectures where pmd_special() is a no-op without adding huge_zero_pfn checks to the generic counter helpers.