From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 ABF9FB67E; Wed, 8 Apr 2026 18:18:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672322; cv=none; b=rhads8pbovr2UXnhW25cPPWoBnNRiTxnuN7h3f1GRAcAOtXeRndVEe6DZATzgaMUBvcd2SWuYkv4G6md22sKbTVW1wKi7/Kmc727bspwgwIxI5ccWPMd3q3/wnefvQxzu5aLoKVjJBHBdT+ycMLpIbZYkBvlmlifg89jeQdyQTM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672322; c=relaxed/simple; bh=mkcWLAhWRxj7kGaTlbk0ATtPz4LJpPLIzudRnHO+19A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BSm0rdaHjwFTH4lcSR4ppZPvjvi/f1Wr09oE6lAUvKLMSC3sEDjFaNuTWsm/FoxJP5JoHeC0zuYOsg428mkgMvL9K0cn1WwEgaySXHKdpPpc4M41/SXwK7iW98oWO3N8g41zRSywVY5EOKYeL5X3P41nN+8fnBtUg6HFbKOHaUI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mgKL8Lbr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mgKL8Lbr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B10BC19421; Wed, 8 Apr 2026 18:18:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775672322; bh=mkcWLAhWRxj7kGaTlbk0ATtPz4LJpPLIzudRnHO+19A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mgKL8LbrLCd+Vem8Yd5TYsADQwYsgVpU350OnNQn6uz6upH4Wj3ihKlmhyw55oE/x hvBrrwp8KQlDgRlCwbHkUs6jp83rEIYffzaE6woZ44x6o/8p9CVrb++y0EfB18/JKn uMmyuhiMiqKku6rVbFRztOJrNTv+xcFzMRH7IvdU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tangxin Xie , Paolo Abeni , Willem de Bruijn , Sasha Levin Subject: [PATCH 6.1 276/312] net: correctly handle tunneled traffic on IPV6_CSUM GSO fallback Date: Wed, 8 Apr 2026 20:03:13 +0200 Message-ID: <20260408175944.056687386@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175933.715315542@linuxfoundation.org> References: <20260408175933.715315542@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Willem de Bruijn [ Upstream commit c4336a07eb6b2526dc2b62928b5104b41a7f81f5 ] NETIF_F_IPV6_CSUM only advertises support for checksum offload of packets without IPv6 extension headers. Packets with extension headers must fall back onto software checksumming. Since TSO depends on checksum offload, those must revert to GSO. The below commit introduces that fallback. It always checks network header length. For tunneled packets, the inner header length must be checked instead. Extend the check accordingly. A special case is tunneled packets without inner IP protocol. Such as RFC 6951 SCTP in UDP. Those are not standard IPv6 followed by transport header either, so also must revert to the software GSO path. Cc: stable@vger.kernel.org Fixes: 864e3396976e ("net: gso: Forbid IPv6 TSO with extensions on devices with only IPV6_CSUM") Reported-by: Tangxin Xie Closes: https://lore.kernel.org/netdev/0414e7e2-9a1c-4d7c-a99d-b9039cf68f40@yeah.net/ Suggested-by: Paolo Abeni Signed-off-by: Willem de Bruijn Link: https://patch.msgid.link/20260320190148.2409107-1-willemdebruijn.kernel@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3586,6 +3586,22 @@ static netdev_features_t dflt_features_c return vlan_features_check(skb, features); } +static bool skb_gso_has_extension_hdr(const struct sk_buff *skb) +{ + if (!skb->encapsulation) + return ((skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6 || + (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && + vlan_get_protocol(skb) == htons(ETH_P_IPV6))) && + skb_transport_header_was_set(skb) && + skb_network_header_len(skb) != sizeof(struct ipv6hdr)); + else + return (!skb_inner_network_header_was_set(skb) || + ((skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6 || + (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && + inner_ip_hdr(skb)->version == 6)) && + skb_inner_network_header_len(skb) != sizeof(struct ipv6hdr))); +} + static netdev_features_t gso_features_check(const struct sk_buff *skb, struct net_device *dev, netdev_features_t features) @@ -3627,11 +3643,7 @@ static netdev_features_t gso_features_ch * so neither does TSO that depends on it. */ if (features & NETIF_F_IPV6_CSUM && - (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6 || - (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && - vlan_get_protocol(skb) == htons(ETH_P_IPV6))) && - skb_transport_header_was_set(skb) && - skb_network_header_len(skb) != sizeof(struct ipv6hdr) && + skb_gso_has_extension_hdr(skb) && !ipv6_has_hopopt_jumbo(skb)) features &= ~(NETIF_F_IPV6_CSUM | NETIF_F_TSO6 | NETIF_F_GSO_UDP_L4);