In the Linux kernel before 4.15, fs/ocfs2/aops.c omits use of a semaphore and consequently has a race condition for access to the extent tree during read operations in DIRECT mode, which allows local users to cause a denial of service (BUG) by modifying a certain e_cpos field.
Exploitability
AV:LAC:HPR:LUI:NScope
S:UImpact
C:NI:NA:H4.7/CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H