From e0b6648b0446e59522819c75ba1dcb09e68d3e94 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Fri, 9 Aug 2024 15:07:30 +0200 Subject: [PATCH] netfilter: nf_tables: Audit log dump reset after the fact 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 Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- 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: -- 2.39.5