In the Linux kernel, the following vulnerability has been resolved:
RDMA/core: Validate the passed in fops for ib_get_ucaps()
Sashiko pointed out it is not safe to rely only on the devt because char/block alias so if the user finds a block device with the same dev_t it can masquerade as a ucap cdev fd.
Test the f_ops to only accept authentic cdevs.
Exploitability
AV:LAC:LPR:LUI:NScope
S:CImpact
C:HI:HA:H8.8/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H