CVE-2026-46161

md/raid10: fix divide-by-zero in setup_geo() with zero far_copies

In the Linux kernel, the following vulnerability has been resolved: md/raid10: fix divide-by-zero in setup_geo() with zero far_copies setup_geo() extracts near_copies (nc) and far_copies (fc) from the user-provided layout parameter without checking for zero. When fc=0 with the "improved" far set layout selected, 'geo->far_set_size = disks / fc' triggers a divide-by-zero. Validate nc and fc immediately after extraction, returning -1 if either is zero.