On Wed, Apr 26, 2017 at 5:15 PM, Willem de Bruijn <willemdebruijn.kernel@xxxxxxxxx> wrote: >>> The patch breaks backward/forward compatibility in a match/target. >>> >>> When the list of the revisions of a given match/target of iptables is not >>> exactly the same as for the kernel counter part (when the kernel module >>> supports less revisions than iptables), then in spite of the supported >>> match/target, " [unsupported revision]" is printed instead of the >>> arguments. See https://bugzilla.netfilter.org/show_bug.cgi?id=1147. >> >> Thanks for the report. >> >>> Please consider reverting the patch. Or we should not stop in >>> xtables_find_match/xtables_find_target at revision checking when the >>> revision does not match, until all possibilities is not exhausted. >> >> This seems like the better solution to me. The patch fixes a real issue >> where garbage is printed by misinterpreting struct fields. Iptables should >> try to lookup the matching revision for a match or target, instead of >> returning the first one. I'll take a look. > > I have a draft patch, but am so far unable to reproduce the problem. > > It may be more subtle than what you describe. xtables_find_match > can call xtables_fully_register_pending_match which calls > compatible_match_revision to decide whether a match revision > is supported and, if multiple revisions are supported, which to prefer. The case reported in bugzilla is for match 'set', which has not had a new revision since v4 in 2014. Building the exact versions of iptables and ipset reported there and disabling v4 support in the kernel correctly reverts to using v3. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
