In the Linux kernel, the following vulnerability has been resolved:

iommu/dma-iommu: Fix wrong scatterlist length assignment in P2PDMA path

In iommu_dma_map_sg(), when handling PCI P2PDMA cases, the DMA length
of the current scatterlist segment `s` is incorrectly assigned from the
head entry `sg->length` instead of the current entry `s->length`.

This typo causes all P2PDMA segments in the scatterlist to inherit the
length of the first segment, leading to corrupted DMA lengths for multi-
segment scatterlists.

Fix this by using `s->length` instead of `sg->length`.