Description: bpf: Fix integer overflow in prealloc_elems_and_freelist()
References:
 https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=30e29a9a2bc6a4888335a6ede968b75cd329657a
 https://lore.kernel.org/bpf/728b238e-a481-eb50-98e9-b0f430ab01e7@gmail.com/
Notes:
 carnil> Commit fixes 557c0c6e7df8 ("bpf: convert stackmap to pre-
 carnil> allocation")
Bugs:
upstream: needed
5.10-upstream-stable: needed
4.19-upstream-stable: needed
4.9-upstream-stable: needed
sid: needed
5.10-bullseye-security: needed
4.19-buster-security: needed
4.9-stretch-security: needed