If a requested extension exists as module and is not loaded,
ebt_check_match() might accidentally use an NFPROTO_UNSPEC one with same
name and fail.
Reproduced with limit match: Given xt_limit and ebt_limit both built as
module, the following would fail:
modprobe xt_limit
ebtables -I INPUT --limit 1/s -j ACCEPT
The fix is to make ebt_check_match() distrust a found NFPROTO_UNSPEC
extension and retry after requesting an appropriate module.
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
bcf4934288