From: Pablo Neira Ayuso pablo@netfilter.org
mainline inclusion from mainline-v6.6-rc3 commit f15f29fd4779be8a418b66e9d52979bb6d6c2325 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I84NFY CVE: CVE-2023-5197
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Chain binding only requires the rule addition/insertion command within the same transaction. Removal of rules from chain bindings within the same transaction makes no sense, userspace does not utilize this feature. Replace nft_chain_is_bound() check to nft_chain_binding() in rule deletion commands. Replace command implies a rule deletion, reject this command too.
Rule flush command can also safely rely on this nft_chain_binding() check because unbound chains are not allowed since 62e1e94b246e ("netfilter: nf_tables: reject unbound chain set before commit phase").
Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING") Reported-by: Kevin Rich kevinrich1337@gmail.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Conflicts: net/netfilter/nf_tables_api.c Signed-off-by: Ziyang Xuan william.xuanziyang@huawei.com --- net/netfilter/nf_tables_api.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 4ac499c6ef47..121ad5981520 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1250,7 +1250,7 @@ static int nft_flush_table(struct nft_ctx *ctx) if (!nft_is_active_next(ctx->net, chain)) continue;
- if (nft_chain_is_bound(chain)) + if (nft_chain_binding(chain)) continue;
ctx->chain = chain; @@ -1295,7 +1295,7 @@ static int nft_flush_table(struct nft_ctx *ctx) if (!nft_is_active_next(ctx->net, chain)) continue;
- if (nft_chain_is_bound(chain)) + if (nft_chain_binding(chain)) continue;
ctx->chain = chain; @@ -2579,6 +2579,9 @@ static int nf_tables_delchain(struct net *net, struct sock *nlsk, return PTR_ERR(chain); }
+ if (nft_chain_binding(chain)) + return -EOPNOTSUPP; + if (nlh->nlmsg_flags & NLM_F_NONREC && chain->use > 0) return -EBUSY; @@ -3474,6 +3477,11 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk, }
if (nlh->nlmsg_flags & NLM_F_REPLACE) { + if (nft_chain_binding(chain)) { + err = -EOPNOTSUPP; + goto err2; + } + trans = nft_trans_rule_add(&ctx, NFT_MSG_NEWRULE, rule); if (trans == NULL) { err = -ENOMEM; @@ -3580,7 +3588,7 @@ static int nf_tables_delrule(struct net *net, struct sock *nlsk, NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_CHAIN]); return PTR_ERR(chain); } - if (nft_chain_is_bound(chain)) + if (nft_chain_binding(chain)) return -EOPNOTSUPP; }
@@ -3610,7 +3618,7 @@ static int nf_tables_delrule(struct net *net, struct sock *nlsk, list_for_each_entry(chain, &table->chains, list) { if (!nft_is_active_next(net, chain)) continue; - if (nft_chain_is_bound(chain)) + if (nft_chain_binding(chain)) continue;
ctx.chain = chain; @@ -9194,6 +9202,9 @@ static void __nft_release_table(struct net *net, struct nft_table *table) ctx.family = table->family; ctx.table = table; list_for_each_entry(chain, &table->chains, list) { + if (nft_chain_binding(chain)) + continue; + ctx.chain = chain; list_for_each_entry_safe(rule, nr, &chain->rules, list) { list_del(&rule->list);