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| author | Runyu Xiao <runyu.xiao@seu.edu.cn> | 2026-06-11 12:21:20 +0800 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2026-06-23 08:11:22 +0200 |
| commit | 11d4bc4e26fb66040a5b5d95e9abf37deac2b1fc (patch) | |
| tree | 6bd5a8bcfc744770877120d55c3ea79f934eb07d /net | |
| parent | 22f9dbed18bcc865d750ed109c6ae2dd4cf2af55 (diff) | |
| download | ath-11d4bc4e26fb66040a5b5d95e9abf37deac2b1fc.tar.gz | |
netfilter: nft_synproxy: stop bypassing the priv->info snapshot
nft_synproxy_eval_v4() and nft_synproxy_eval_v6() already take a
whole-object READ_ONCE() snapshot of the shared priv->info state before
building the SYNACK reply, but nft_synproxy_tcp_options() still masks
opts->options with priv->info.options from the live shared object.
When a named synproxy object is updated concurrently with SYN traffic,
the eval path can then mix mss and timestamp handling from the local
snapshot with an options mask taken from a newer configuration, so one
SYNACK no longer reflects a coherent synproxy configuration.
Use info->options so nft_synproxy_tcp_options() stays on the same local
snapshot that the eval path already copied from priv->info.
Fixes: ee394f96ad75 ("netfilter: nft_synproxy: add synproxy stateful object support")
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nft_synproxy.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/net/netfilter/nft_synproxy.c b/net/netfilter/nft_synproxy.c index 7641f249614c9..9ed288c9d1688 100644 --- a/net/netfilter/nft_synproxy.c +++ b/net/netfilter/nft_synproxy.c @@ -24,14 +24,13 @@ static const struct nla_policy nft_synproxy_policy[NFTA_SYNPROXY_MAX + 1] = { static void nft_synproxy_tcp_options(struct synproxy_options *opts, const struct tcphdr *tcp, struct synproxy_net *snet, - struct nf_synproxy_info *info, - const struct nft_synproxy *priv) + struct nf_synproxy_info *info) { this_cpu_inc(snet->stats->syn_received); if (tcp->ece && tcp->cwr) opts->options |= NF_SYNPROXY_OPT_ECN; - opts->options &= priv->info.options; + opts->options &= info->options; opts->mss_encode = opts->mss_option; opts->mss_option = info->mss; if (opts->options & NF_SYNPROXY_OPT_TIMESTAMP) @@ -56,7 +55,7 @@ static void nft_synproxy_eval_v4(const struct nft_synproxy *priv, if (tcp->syn) { /* Initial SYN from client */ - nft_synproxy_tcp_options(opts, tcp, snet, &info, priv); + nft_synproxy_tcp_options(opts, tcp, snet, &info); synproxy_send_client_synack(net, skb, tcp, opts); consume_skb(skb); regs->verdict.code = NF_STOLEN; @@ -87,7 +86,7 @@ static void nft_synproxy_eval_v6(const struct nft_synproxy *priv, if (tcp->syn) { /* Initial SYN from client */ - nft_synproxy_tcp_options(opts, tcp, snet, &info, priv); + nft_synproxy_tcp_options(opts, tcp, snet, &info); synproxy_send_client_synack_ipv6(net, skb, tcp, opts); consume_skb(skb); regs->verdict.code = NF_STOLEN; |