The snd_msndmidi_input_read function in sound/isa/msnd/msnd_midi.c in the Linux kernel through 4.11.7 allows local users to cause a denial of service (over-boundary access) or possibly have unspecified other impact by changing the value of a message queue head pointer between two kernel reads of that value, aka a "double fetch" vulnerability. Pengfei Wang discovered that the Turtle Beach MultiSound audio device driver in the Linux kernel contained race conditions when fetching from the ring-buffer. A local attacker could use this to cause a denial of service (infinite loop).