[PATCH net 6/8] netfilter: nf_tables: Audit log dump reset after the fact
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2024-08-14 22:20:53
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Phil Sutter <phil@nwl.cc>
In theory, dumpreset may fail and invalidate the preceeding log message.
Fix this and use the occasion to prepare for object reset locking, which
benefits from a few unrelated changes:
* Add an early call to nfnetlink_unicast if not resetting which
effectively skips the audit logging but also unindents it.
* Extract the table's name from the netlink attribute (which is verified
via earlier table lookup) to not rely upon validity of the looked up
table pointer.
* Do not use local variable family, it will vanish.
Fixes: 8e6cf365e1d5 ("audit: log nftables configuration change events")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_tables_api.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 481ee78e77bc..4fa132715fcc 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c@@ -8055,6 +8055,7 @@ static int nf_tables_dump_obj_done(struct netlink_callback *cb) static int nf_tables_getobj(struct sk_buff *skb, const struct nfnl_info *info, const struct nlattr * const nla[]) { + const struct nftables_pernet *nft_net = nft_pernet(info->net); struct netlink_ext_ack *extack = info->extack; u8 genmask = nft_genmask_cur(info->net); u8 family = info->nfmsg->nfgen_family;
@@ -8064,6 +8065,7 @@ static int nf_tables_getobj(struct sk_buff *skb, const struct nfnl_info *info, struct sk_buff *skb2; bool reset = false; u32 objtype; + char *buf; int err; if (info->nlh->nlmsg_flags & NLM_F_DUMP) {
@@ -8102,27 +8104,23 @@ static int nf_tables_getobj(struct sk_buff *skb, const struct nfnl_info *info, if (NFNL_MSG_TYPE(info->nlh->nlmsg_type) == NFT_MSG_GETOBJ_RESET) reset = true; - if (reset) { - const struct nftables_pernet *nft_net; - char *buf; - - nft_net = nft_pernet(net); - buf = kasprintf(GFP_ATOMIC, "%s:%u", table->name, nft_net->base_seq); - - audit_log_nfcfg(buf, - family, - 1, - AUDIT_NFT_OP_OBJ_RESET, - GFP_ATOMIC); - kfree(buf); - } - err = nf_tables_fill_obj_info(skb2, net, NETLINK_CB(skb).portid, info->nlh->nlmsg_seq, NFT_MSG_NEWOBJ, 0, family, table, obj, reset); if (err < 0) goto err_fill_obj_info; + if (!reset) + return nfnetlink_unicast(skb2, net, NETLINK_CB(skb).portid); + + buf = kasprintf(GFP_ATOMIC, "%.*s:%u", + nla_len(nla[NFTA_OBJ_TABLE]), + (char *)nla_data(nla[NFTA_OBJ_TABLE]), + nft_net->base_seq); + audit_log_nfcfg(buf, info->nfmsg->nfgen_family, 1, + AUDIT_NFT_OP_OBJ_RESET, GFP_ATOMIC); + kfree(buf); + return nfnetlink_unicast(skb2, net, NETLINK_CB(skb).portid); err_fill_obj_info:
--
2.30.2