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 7CA7D3B47E3; Tue, 21 Jul 2026 20:32:46 +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=1784665967; cv=none; b=oNgHJtVh8AVEwDpNkdmo/fGGJAxQFY1JYphUUmLSsRsupg6uxTknQ4POMH4xZgMc8vq1Oqjfv0zWTsk6lFyU5v69FYF47IiCrAyMbCcoWEac7+1ryQ7ohLPjd+xI+n5rjuthOfD67wuoYATMQbZ280MFBLCp23aE303qkChyOYY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784665967; c=relaxed/simple; bh=FMNBfGSz7/hAOV7At4R8TV+kNBWeD4KTLCOLGexU/ho=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pDdNqgEG/LPC7p7JcJVR5uJ8wB+Xc9SqaMnfEHuBkDJ3tKKtaWvlue1Ooo0cpbgpSgKH3VztXoKcyI5eRud6ngjP0LH33ee6ByDfEs58MzhLgzJHJM89a9SG9p79QeZxgkWBUgPmwQ8uN2NrgLOZPSZzVlV3YKUNGQQYqGyIdtw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=srzsXxY3; 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="srzsXxY3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE5561F00A3A; Tue, 21 Jul 2026 20:32:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784665966; bh=YyA6FVxjS5Vr1x2TvSh90KufMl0/VsD1ljrQS3vv5bw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=srzsXxY3PpVsshPtYAVLQ/GO0kzBTuzRlbJ1eHG8i7qpyrsdz+W/3P0sDQ+nP26hb c0tsgsNFYhtkkcr9BfLcLZQ/LG996Ih4HafHEe7aNreRlpT47Be4OT9NpZ4W7G2n96 hRCU14xBgwTUfAm0BIqFC8TG3wOcKPhL14C5q1as= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Leon Hwang , Leon Hwang , Alexei Starovoitov , Sasha Levin Subject: [PATCH 6.6 0502/1266] bpf: Update transport_header when encapsulating UDP tunnel in lwt Date: Tue, 21 Jul 2026 17:15:39 +0200 Message-ID: <20260721152453.080822700@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Leon Hwang [ Upstream commit 82d7d0adbc678064543e9d254864f6b4ea4a388c ] Currently, bpf_lwt_push_ip_encap() does not update skb->transport_header. When a driver, e.g. ice, reuses the stale skb->transport_header to offload checksum computation to NIC hardware, VxLAN packets encapsulated by bpf_lwt_push_encap() helper may be dropped due to incorrect checksum. Update skb->transport_header in bpf_lwt_push_ip_encap() whenever the encapsulated packet uses UDP, so checksum offload works correctly. Fixes: 52f278774e79 ("bpf: implement BPF_LWT_ENCAP_IP mode in bpf_lwt_push_encap") Cc: Leon Hwang Signed-off-by: Leon Hwang Link: https://lore.kernel.org/r/20260602150931.49629-2-leon.hwang@linux.dev Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- net/core/lwt_bpf.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/net/core/lwt_bpf.c b/net/core/lwt_bpf.c index 4a0797f0a154b2..efbd9eecb00d17 100644 --- a/net/core/lwt_bpf.c +++ b/net/core/lwt_bpf.c @@ -590,6 +590,7 @@ static int handle_gso_encap(struct sk_buff *skb, bool ipv4, int encap_len) int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress) { + bool is_udp_tunnel; struct iphdr *iph; bool ipv4; int err; @@ -603,10 +604,16 @@ int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress) ipv4 = true; if (unlikely(len < iph->ihl * 4)) return -EINVAL; + is_udp_tunnel = iph->protocol == IPPROTO_UDP; + if (unlikely(is_udp_tunnel && len < iph->ihl * 4 + sizeof(struct udphdr))) + return -EINVAL; } else if (iph->version == 6) { ipv4 = false; if (unlikely(len < sizeof(struct ipv6hdr))) return -EINVAL; + is_udp_tunnel = ((struct ipv6hdr *)iph)->nexthdr == NEXTHDR_UDP; + if (unlikely(is_udp_tunnel && len < sizeof(struct ipv6hdr) + sizeof(struct udphdr))) + return -EINVAL; } else { return -EINVAL; } @@ -628,6 +635,11 @@ int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, bool ingress) if (ingress) skb_postpush_rcsum(skb, iph, len); skb_reset_network_header(skb); + if (is_udp_tunnel) { + size_t iph_sz = ipv4 ? iph->ihl * 4 : sizeof(struct ipv6hdr); + + skb_set_transport_header(skb, skb_network_offset(skb) + iph_sz); + } memcpy(skb_network_header(skb), hdr, len); bpf_compute_data_pointers(skb); skb_clear_hash(skb); -- 2.53.0