system
Describe <CVE-2016-4557>.
user
What is <CVE-2016-4557>?
assistant
The replace_map_fd_with_map_ptr function in kernel/bpf/verifier.c in the Linux kernel before 4.5.5 does not properly maintain an fd data structure, which allows local users to gain privileges or cause a denial of service (use-after-free) via crafted BPF instructions that reference an incorrect file descriptor..