Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: do not repeat pte_offset_map_lock() until success DAMON’s virtual address space operation set implementation (vaddr) calls pte_offset_map_lock() inside the page table walk callback function. This is for reading and writing page table accessed bits. If pte_offset_map_lock() fails, it retries by returning the page table walk callback function with ACTION_AGAIN. pte_offset_map_lock() can continuously fail if the target is a pmd migration entry, though. Hence it could cause an infinite page table walk if the migration cannot be done until the page table walk is finished. This indeed caused a soft lockup when CPU hotplugging and DAMON were running in parallel. Avoid the infinite loop by simply not retrying the page table walk. DAMON is promising only a best-effort accuracy, so missing access to such pages is no problem.Details
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 13 | Planned | — |
| Ubuntu 24.04 | Released |
39 kernels
|
| Ubuntu 24.04 AWS | Planned | — |