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.
https://git.kernel.org/stable/c/aa181287ebdcc53ee0ba5c2f8243e2d541ebc19b
https://git.kernel.org/stable/c/96b6e98ff12d50ed5817230c6f1188e1150d225d
https://git.kernel.org/stable/c/4a1b1ac2744694a2ecd66a84bdb1445f4ef24bee