In the Linux kernel, the following vulnerability has been resolved: fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region() afu

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

fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()

afu_ioctl_dma_map() accepts a 64-bit length from userspace via
DFL_FPGA_PORT_DMA_MAP ioctl without an upper bound check. The value
is passed to afu_dma_pin_pages() where npages is derived as
length >> PAGE_SHIFT and passed to pin_user_pages_fast() which takes
int nr_pages, causing implicit truncation if length is very large.

Validate map.length at the ioctl entry point before calling
afu_dma_map_region(), rejecting values whose page count exceeds
INT_MAX.