prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kernel through 5.14.9 allows unprivileged users to trigger an eBPF multiplication integer overflow with a resultant out-of-bounds write. CREATE(Triage):(User=admin) CVE-2021-41864 (https://nvd.nist.gov/vuln/detail/CVE-2021-41864)