In the Linux kernel, the following vulnerability has been resolved:
swiotlb: Preserve allocation virtual address for dynamic pools
swiotlb_alloc_tlb() can allocate from the DMA atomic pool when a decrypted
pool is needed from atomic context. With CONFIG_DMA_DIRECT_REMAP, the
atomic pool is backed by remapped virtual addresses, which are not the same
as the direct-map addresses returned by phys_to_virt().
swiotlb_init_io_tlb_pool() currently reconstructs the pool virtual address
from the physical start address. For atomic-pool backed allocations this
stores the wrong address in pool->vaddr.
Later, swiotlb_free_tlb() passes
that address to dma_free_from_pool(), which will fail to recognize the
chunk
Pass the virtual address returned by the allocation path into
swiotlb_init_io_tlb_pool(), and store that address in pool->vaddr. This
keeps the pool free path using the same virtual address as the allocator.
Attack Parameters
Impact Assessment
CVSS Vector v3.1