An issue was discovered in the Linux kernel 3.16 through 5.5.6. set_fdc in
drivers/block/floppy.c leads to a wait_til_ready out-of-bounds read because
the FDC index is not checked for errors before assigning it, aka
CID-2e90ca68b0d2.

Jordy Zomer discovered that the floppy driver in the Linux kernel did not
properly check for errors in some situations. A local attacker could
possibly use this to cause a denial of service (system crash) or possibly
expose sensitive information.