Memory Management Vulnerability in Linux Kernel Affecting QEMU

CVE-2022-49760

What is CVE-2022-49760?

A critical issue has been identified in the Linux kernel's handling of the PTE marker within the hugetlb_change_protection function. This vulnerability arises when operating with QEMU's virtio-mem and background snapshots, which can lead to incorrect handling of memory protection, particularly during the usage of userfaultfd write-protection (uffd-wp). The improper management of PTE markers may result in a situation where invalid memory references are processed, ultimately causing kernel panic or crashes. Specific scenarios trigger this flaw, such as remapping memory backed by huge pages in conjunction with uffd-wp, potentially allowing malicious users to manipulate memory access in unintended ways.

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