The snd_msndmidi_input_read function in sound/isa/msnd/msnd_midi.c in the Linux kernel before 4.13, 4.9.50, 4.4.99 and 4.1.45 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.
The snd_msndmidi_input_read function in sound/isa/msnd/msnd_midi.c in the Linux kernel before 4.13, 4.9.50, 4.4.99 and 4.1.45 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.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=20e2b791796bd68816fa115f12be5320de2b8021 https://bugzilla.kernel.org/show_bug.cgi?id=196133