Re: [PATCH net-next] bpf, lpm: fix overflows in trie_alloc checks

[David Miller <davem@davemloft.net>]

From: Daniel Borkmann <daniel@iogearbox.net>
Date: Wed,  8 Feb 2017 01:19:43 +0100

> Cap the maximum (total) value size and bail out if larger than KMALLOC_MAX_SIZE
> as otherwise it doesn't make any sense to proceed further, since we're
> guaranteed to fail to allocate elements anyway in lpm_trie_node_alloc();
> likleyhood of failure is still high for large values, though, similarly
> as with htab case in non-prealloc.
> 
> Next, make sure that cost vars are really u64 instead of size_t, so that we
> don't overflow on 32 bit and charge only tiny map.pages against memlock while
> allowing huge max_entries; cap also the max cost like we do with other map
> types.
> 
> Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
> Acked-by: Alexei Starovoitov <ast@kernel.org>

Applied, thanks Daniel.