In the Linux kernel before 5.2.3, drivers/block/floppy.c allows a denial of service by setup_format_params division-by-zero. Two consecutive ioctls can trigger the bug: the first one should set the drive geometry with .sect and .rate values that make F_SECT_PER_TRACK be zero. Next, the floppy format operation should be called. It can be triggered by an unprivileged local user even when a floppy disk has not been inserted. NOTE: QEMU creates the floppy device by default.
4.4.0-161.1894.4.0-1092.1034.15.0-1047.49~16.04.14.15.0-1056.614.15.0-1041.434.15.0-60.67~16.04.14.4.0-1056.634.15.0-1022.25~16.04.14.4.0-1120.1294.4.0-1124.130Exploitability
AV:LAC:LAT:NPR:HUI:NVulnerable System
VC:NVI:NVA:HSubsequent System
SC:NSI:NSA:NCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N