Executive brief
A logic error was identified in the Linux kernel's memory management for ARM64 systems. The system was incorrectly performing safety checks when mapping memory addresses, which could lead to unnecessary warnings or failures when the kernel attempted to manage specific memory regions like those used for security debugging or kernel modules. While primarily a technical bug, fixing it ensures the stability and correct operation of the operating system's memory handling.
Technical details
A logic error existed in the arm64 MMU initialization code where the sanity check for virtual address ranges was incorrectly defined. The condition `(virt >= PAGE_END) && (virt < VMALLOC_START)` was a historical artifact that erroneously excluded the KASAN shadow region and the module region from being valid for mapping updates. This 'thinko' originated from previous refactors of the kernel virtual address space layout. The fix corrects the condition to check against `PAGE_OFFSET`, ensuring the check properly validates whether an address is within the TTBR1 (kernel) address space. This is a local vulnerability with low impact, primarily affecting kernel stability and internal memory consistency checks.
Affected products
- Linux Linux Kernel arm64 architecture versions prior to 6.5-rc1
Timeline
- 2023-06-15: patched: Initial patch submitted by Mark Rutland
- 2025-12-24: advisory: CVE-2023-53989 published by NVD
References
- https://git.kernel.org/stable/c/32020fc2a8373d3de35ae6d029d5969a42651e7a
- https://git.kernel.org/stable/c/621619f626cbe702ddbdc54117f3868b8ebd8129
- https://git.kernel.org/stable/c/9d8d3df71516ec3236d8d93ff029d251377ba4b1
- https://git.kernel.org/stable/c/ab9b4008092c86dc12497af155a0901cc1156999
- https://git.kernel.org/stable/c/b03c7fcc5ed854d0e1b27e9abf12428bfa751a37
- https://git.kernel.org/stable/c/c7a9e967cc9615a1dabc5e0e6fdbe88a172d5a5b