From: Thadeu Lima de Souza Cascardo cascardo@canonical.com
commit 36d5b2913219ac853908b0f1c664345e04313856 upstream.
When doing lookups for rules on the same batch by using its ID, a rule from a different chain can be used. If a rule is added to a chain but tries to be positioned next to a rule from a different chain, it will be linked to chain2, but the use counter on chain1 would be the one to be incremented.
When looking for rules by ID, use the chain that was used for the lookup by name. The chain used in the context copied to the transaction needs to match that same chain. That way, struct nft_rule does not need to get enlarged with another member.
Fixes: 1a94e38d254b ("netfilter: nf_tables: add NFTA_RULE_ID attribute") Fixes: 75dd48e2e420 ("netfilter: nf_tables: Support RULE_ID reference in new rule") Signed-off-by: Thadeu Lima de Souza Cascardo cascardo@canonical.com Cc: stable@vger.kernel.org Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nf_tables_api.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3156,6 +3156,7 @@ static int nft_table_validate(struct net }
static struct nft_rule *nft_rule_lookup_byid(const struct net *net, + const struct nft_chain *chain, const struct nlattr *nla);
#define NFT_RULE_MAXEXPRS 128 @@ -3243,7 +3244,7 @@ static int nf_tables_newrule(struct net return PTR_ERR(old_rule); } } else if (nla[NFTA_RULE_POSITION_ID]) { - old_rule = nft_rule_lookup_byid(net, nla[NFTA_RULE_POSITION_ID]); + old_rule = nft_rule_lookup_byid(net, chain, nla[NFTA_RULE_POSITION_ID]); if (IS_ERR(old_rule)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_POSITION_ID]); return PTR_ERR(old_rule); @@ -3382,6 +3383,7 @@ err1: }
static struct nft_rule *nft_rule_lookup_byid(const struct net *net, + const struct nft_chain *chain, const struct nlattr *nla) { u32 id = ntohl(nla_get_be32(nla)); @@ -3391,6 +3393,7 @@ static struct nft_rule *nft_rule_lookup_ struct nft_rule *rule = nft_trans_rule(trans);
if (trans->msg_type == NFT_MSG_NEWRULE && + trans->ctx.chain == chain && id == nft_trans_rule_id(trans)) return rule; } @@ -3439,7 +3442,7 @@ static int nf_tables_delrule(struct net
err = nft_delrule(&ctx, rule); } else if (nla[NFTA_RULE_ID]) { - rule = nft_rule_lookup_byid(net, nla[NFTA_RULE_ID]); + rule = nft_rule_lookup_byid(net, chain, nla[NFTA_RULE_ID]); if (IS_ERR(rule)) { NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_ID]); return PTR_ERR(rule);