diff mbox series

[net,4/8] netfilter: nf_tables: do not allow RULE_ID to refer to another chain

Message ID 20220809220532.130240-5-pablo@netfilter.org (mailing list archive)
State Accepted
Commit 36d5b2913219ac853908b0f1c664345e04313856
Delegated to: Netdev Maintainers
Headers show
Series [net,1/8] netfilter: nf_tables: validate variable length element extension | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Pull request is its own cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/cc_maintainers fail 1 blamed authors not CCed: phil@nwl.cc; 4 maintainers not CCed: coreteam@netfilter.org kadlec@netfilter.org phil@nwl.cc fw@strlen.de
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 16 this patch: 16
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns WARNING: line length of 96 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Pablo Neira Ayuso Aug. 9, 2022, 10:05 p.m. UTC 
From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

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>
---
 net/netfilter/nf_tables_api.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 041accbaca32..0c3c0523e5f2 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3373,6 +3373,7 @@  static int nft_table_validate(struct net *net, const struct nft_table *table)
 }
 
 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
@@ -3461,7 +3462,7 @@  static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 				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);
@@ -3606,6 +3607,7 @@  static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 }
 
 static struct nft_rule *nft_rule_lookup_byid(const struct net *net,
+					     const struct nft_chain *chain,
 					     const struct nlattr *nla)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
@@ -3616,6 +3618,7 @@  static struct nft_rule *nft_rule_lookup_byid(const struct net *net,
 		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;
 	}
@@ -3665,7 +3668,7 @@  static int nf_tables_delrule(struct sk_buff *skb, const struct nfnl_info *info,
 
 			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);