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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
e95a9851787bbb3cd4deb40fe8bab03f731852d1 to < ab4f0f68cf4773dc0513baccbbe790c80a301773affectede95a9851787bbb3cd4deb40fe8bab03f731852d1 to < cf73ef2a761df9329af116c905a7a94b317921e4affectede95a9851787bbb3cd4deb40fe8bab03f731852d1 to < 7a96b0f657c8d799ea5b8e02fc9ec7cca0e6e7ffaffectede95a9851787bbb3cd4deb40fe8bab03f731852d1 to < 850cc4a84b36a0062dcd0391acd2450e20ab0767affectede95a9851787bbb3cd4deb40fe8bab03f731852d1 to < 480a39b0a12c977ed6e755f3d12a23424c57d11faffectede95a9851787bbb3cd4deb40fe8bab03f731852d1 to < 9bdad082d44bdcf93716973dcba6be77e8a06e7baffected
Linux Linux
Default version status: affected
6.0affected0 to < 6.0unaffected6.1.191 to ≤ 6.1.*unaffected6.6.160 to ≤ 6.6.*unaffected6.12.112 to ≤ 6.12.*unaffected6.18.55 to ≤ 6.18.*unaffected7.2.9 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/ab4f0f68cf4773dc0513baccbbe790c80a301773 ↗
- https://git.kernel.org/stable/c/cf73ef2a761df9329af116c905a7a94b317921e4 ↗
- https://git.kernel.org/stable/c/7a96b0f657c8d799ea5b8e02fc9ec7cca0e6e7ff ↗
- https://git.kernel.org/stable/c/850cc4a84b36a0062dcd0391acd2450e20ab0767 ↗
- https://git.kernel.org/stable/c/480a39b0a12c977ed6e755f3d12a23424c57d11f ↗
- https://git.kernel.org/stable/c/9bdad082d44bdcf93716973dcba6be77e8a06e7b ↗