Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: preserve mremap address delta when skipping page tables move_hugetlb_page_tables() optimizes mremap() by advancing to the last entry in the page table when the source page table does not exist, either initially or after unsharing a PMD table. The common loop increment then steps to the first entry in the next page table. However, the code advances both the source and destination addresses to the last entries in their respective page tables, which is wrong. The destination address must be advanced only by the same amount as the source address. If the source and destination offsets within their page tables differ, the destination address can be advanced too far, causing follow-up issues. Fix this by advancing the destination address by the source advance distance. With a reproducer, we were able to trigger a kernel panic on x86-64. With this fix in place, we can no longer reproduce the issue.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund7 Oct 2026WID-SEC-2026-3804

  Linux Kernel: Multiple vulnerabilities allow an unspecified attack Translated from German

  CVE-2026-98373CVE-2026-98374

[ References ]References

• git.kernel.org/stable/c/480a39b0a12c977ed6e755f3d12a23424c57d11f
• git.kernel.org/stable/c/7a96b0f657c8d799ea5b8e02fc9ec7cca0e6e7ff
• git.kernel.org/stable/c/850cc4a84b36a0062dcd0391acd2450e20ab0767
• git.kernel.org/stable/c/9bdad082d44bdcf93716973dcba6be77e8a06e7b
• git.kernel.org/stable/c/cf73ef2a761df9329af116c905a7a94b317921e4