From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 51D46415F2C; Tue, 21 Jul 2026 17:51:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784656316; cv=none; b=O/Q/wsXDgAs8Hxgsx9yyiNbkvv0FrUQ3fCCVZPW9Y3ZfL4uai29iIH7nRxNWq1BUyBRm2Q6YWFFRba3zVnkgg4OCoGSOFz9ne8lgcesUGn6akhIQlPPb39m6/eQMk5EfNAc/Imo+dwoP82OX456pBeP8F6WKCwM+uFsLY2o1HaY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784656316; c=relaxed/simple; bh=UOH9YHsxoFX9ASjBIInLHuFrUvbSIlkThIXwQ6C+qE0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=M3XOdhGviYrfEGEUw9/nkY9gPd8Chq0fhd2F2fgOE8nmWuRcclR8l8hdKIx4lfWPXRjnr1iOr23RXnqx4sXWi4uI6FNo6asS2nc2Ma4J6teGCbKaDnK639ER9U3VL+OqxbGJExnbqsZ4nDOamaZd0xffct1EklywB8tt2jbECRI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HSpnmJGQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HSpnmJGQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A77B21F000E9; Tue, 21 Jul 2026 17:51:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784656315; bh=/NZaZJA/Q2vKLjQXuLnboHRktX3k9zQkiVlAWjl4Pik=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HSpnmJGQHNt/ZQ6FlW+7urOlOIS7JRVJyA0sLUuka1SCG58m4lqr+lWf5u7BJFnAL kA4Vl+V1GVxkstlEwoUUADRYECn4Gm3HD5GTY+x70OxXsfG0K59ZE527epiHeuA6a6 BG4PPjEsIUPr/r4/jOaA4Hj2O67vU+RsM3sf1sCw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Fernando Fernandez Mancera , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 6.18 0342/1611] netfilter: synproxy: drop packets if timestamp adjustment fails Date: Tue, 21 Jul 2026 17:07:38 +0200 Message-ID: <20260721152522.814102932@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152514.750365251@linuxfoundation.org> References: <20260721152514.750365251@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Fernando Fernandez Mancera [ Upstream commit 63d29ee95c4ab5976d660182d2e4733bb4a091d8 ] If a packet was malformed or if skb_ensure_writable() failed, the synproxy_tstamp_adjust() function returned 0 indicating an error but it was ignored on the callers. Make the function return a boolean instead to clarify the result and drop the packet if synproxy_tstamp_adjust() failed due to ENOMEM from skb_ensure_writable(). In addition, if there are malformed options, skip the tstamp update but do not drop the packet as that should be done by the policy directly. Fixes: 48b1de4c110a ("netfilter: add SYNPROXY core/target") Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nf_synproxy_core.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/net/netfilter/nf_synproxy_core.c b/net/netfilter/nf_synproxy_core.c index a277b2bd3275dc..a90511238ec378 100644 --- a/net/netfilter/nf_synproxy_core.c +++ b/net/netfilter/nf_synproxy_core.c @@ -183,7 +183,7 @@ synproxy_check_timestamp_cookie(struct synproxy_options *opts) opts->options |= opts->tsecr & (1 << 5) ? NF_SYNPROXY_OPT_ECN : 0; } -static unsigned int +static bool synproxy_tstamp_adjust(struct sk_buff *skb, unsigned int protoff, struct tcphdr *th, struct nf_conn *ct, enum ip_conntrack_info ctinfo, @@ -193,13 +193,13 @@ synproxy_tstamp_adjust(struct sk_buff *skb, unsigned int protoff, __be32 *ptr, old; if (synproxy->tsoff == 0) - return 1; + return true; optoff = protoff + sizeof(struct tcphdr); optend = protoff + th->doff * 4; if (skb_ensure_writable(skb, optend)) - return 0; + return false; th = (struct tcphdr *)(skb->data + protoff); @@ -208,7 +208,7 @@ synproxy_tstamp_adjust(struct sk_buff *skb, unsigned int protoff, switch (op[0]) { case TCPOPT_EOL: - return 1; + return true; case TCPOPT_NOP: optoff++; continue; @@ -216,7 +216,7 @@ synproxy_tstamp_adjust(struct sk_buff *skb, unsigned int protoff, if (optoff + 1 == optend || optoff + op[1] > optend || op[1] < 2) - return 0; + return true; if (op[0] == TCPOPT_TIMESTAMP && op[1] == TCPOLEN_TIMESTAMP) { if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) { @@ -232,12 +232,12 @@ synproxy_tstamp_adjust(struct sk_buff *skb, unsigned int protoff, } inet_proto_csum_replace4(&th->check, skb, old, *ptr, false); - return 1; + return true; } optoff += op[1]; } } - return 1; + return true; } #ifdef CONFIG_PROC_FS @@ -748,7 +748,9 @@ ipv4_synproxy_hook(void *priv, struct sk_buff *skb, break; } - synproxy_tstamp_adjust(skb, thoff, th, ct, ctinfo, synproxy); + if (!synproxy_tstamp_adjust(skb, thoff, th, ct, ctinfo, synproxy)) + return NF_DROP_REASON(skb, SKB_DROP_REASON_NETFILTER_DROP, ENOMEM); + return NF_ACCEPT; } EXPORT_SYMBOL_GPL(ipv4_synproxy_hook); @@ -1176,7 +1178,9 @@ ipv6_synproxy_hook(void *priv, struct sk_buff *skb, break; } - synproxy_tstamp_adjust(skb, thoff, th, ct, ctinfo, synproxy); + if (!synproxy_tstamp_adjust(skb, thoff, th, ct, ctinfo, synproxy)) + return NF_DROP_REASON(skb, SKB_DROP_REASON_NETFILTER_DROP, ENOMEM); + return NF_ACCEPT; } EXPORT_SYMBOL_GPL(ipv6_synproxy_hook); -- 2.53.0