Executive brief
A vulnerability was identified in the Linux kernel's memory management component. Under specific conditions like high memory pressure, the system could trigger an internal error state (kernel warning) when adding new memory blocks. This issue primarily affects system stability rather than direct data security.
Technical details
In the Linux kernel's drivers/base/memory.c, a vulnerability existed where mem->altmap was assigned before the successful completion of __add_memory_block(). If __add_memory_block() failed at the xa_store() stage (e.g., due to memory pressure), the subsequent call to device_unregister() would trigger memory_block_release() while mem->altmap was still populated, resulting in a WARN_ON(mem->altmap) state. The fix involves delaying the assignment of mem->altmap until after the memory block has been successfully registered. This issue was notably observed when using the virtio-mem driver.
Affected products
- Linux Linux Kernel 6.6 to 6.6.144, 6.12 to 6.12.95, 6.18 to 6.18.37, 7.0 to 7.0.14, 7.1 to 7.1.2
Timeline
- 2026-07-24: advisory: CVE-2026-64244 published by NVD
References
- https://git.kernel.org/stable/c/059ac6252a63edf1cea79bf30bd860a8c264b62c
- https://git.kernel.org/stable/c/22dc0d042f02ce82aa61422ea5f232628bfd9e9c
- https://git.kernel.org/stable/c/6c25bf4e44a2b6a14332f952bba0974521f5b72d
- https://git.kernel.org/stable/c/802e113cf120df7208e4c7e604950a85e87120a8
- https://git.kernel.org/stable/c/a2b8d7827f48ee54a686cb80e4a1d0ff954ec42a
- https://git.kernel.org/stable/c/bc3dd82a0ffd488bb902f4c69c3d28fd4088d973