[Jammy, OEM-5.17, OEM-6.0, OEM-6.1, Lunar 2/2] netfilter: nf_tables: disallow rule addition to bound chain via NFTA_RULE_CHAIN_ID
Thadeu Lima de Souza Cascardo
cascardo at canonical.com
Thu Aug 3 15:15:24 UTC 2023
From: Pablo Neira Ayuso <pablo at netfilter.org>
Bail out with EOPNOTSUPP when adding rule to bound chain via
NFTA_RULE_CHAIN_ID. The following warning splat is shown when
adding a rule to a deleted bound chain:
WARNING: CPU: 2 PID: 13692 at net/netfilter/nf_tables_api.c:2013 nf_tables_chain_destroy+0x1f7/0x210 [nf_tables]
CPU: 2 PID: 13692 Comm: chain-bound-rul Not tainted 6.1.39 #1
RIP: 0010:nf_tables_chain_destroy+0x1f7/0x210 [nf_tables]
Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Reported-by: Kevin Rich <kevinrich1337 at gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo at netfilter.org>
Signed-off-by: Florian Westphal <fw at strlen.de>
(cherry picked from commit 0ebc1064e4874d5987722a2ddbc18f94aa53b211)
CVE-2023-3995
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo at canonical.com>
---
net/netfilter/nf_tables_api.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index c22b077d882f..b3b053979d60 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3550,8 +3550,6 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_CHAIN]);
return PTR_ERR(chain);
}
- if (nft_chain_is_bound(chain))
- return -EOPNOTSUPP;
} else if (nla[NFTA_RULE_CHAIN_ID]) {
chain = nft_chain_lookup_byid(net, table, nla[NFTA_RULE_CHAIN_ID],
@@ -3564,6 +3562,9 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
return -EINVAL;
}
+ if (nft_chain_is_bound(chain))
+ return -EOPNOTSUPP;
+
if (nla[NFTA_RULE_HANDLE]) {
handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_HANDLE]));
rule = __nft_rule_lookup(chain, handle);
--
2.34.1
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