3.16.63-rc1 review patch. If anyone has any objections, please let me know.
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From: Florian Westphal fw@strlen.de
commit 447750f281abef547be44fdcfe3bc4447b3115a8 upstream.
Its possible to set both HANDLE and POSITION when replacing a rule. In this case, the rule at POSITION gets replaced using the userspace-provided handle. Rule handles are supposed to be generated by the kernel only.
Duplicate handles should be harmless, however better disable this "feature" by only checking for the POSITION attribute on insert operations.
Fixes: 5e94846686d0 ("netfilter: nf_tables: add insert operation") Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org [bwh: Backported to 3.16: - Don't use extack - Adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1767,16 +1767,13 @@ static int nf_tables_newrule(struct sock
if (chain->use == UINT_MAX) return -EOVERFLOW; - } - - if (nla[NFTA_RULE_POSITION]) { - if (!(nlh->nlmsg_flags & NLM_F_CREATE)) - return -EOPNOTSUPP;
- pos_handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_POSITION])); - old_rule = __nf_tables_rule_lookup(chain, pos_handle); - if (IS_ERR(old_rule)) - return PTR_ERR(old_rule); + if (nla[NFTA_RULE_POSITION]) { + pos_handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_POSITION])); + old_rule = __nf_tables_rule_lookup(chain, pos_handle); + if (IS_ERR(old_rule)) + return PTR_ERR(old_rule); + } }
nft_ctx_init(&ctx, skb, nlh, afi, table, chain, nla);