From patchwork Fri Mar 15 15:17:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 13593613 X-Patchwork-Delegate: kuba@kernel.org 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 0979B3D3B7 for ; Fri, 15 Mar 2024 15:17:37 +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=1710515858; cv=none; b=KSNhszTRq5hJcv6B38zwOEaXfeKH7KxIdIaDTc3QkN0fxFdWuw5cTXScDAtvXa5BS3CVX7vXVuVMu+DBI2KTOvonjiauujvEYTPSy2VYqR8v3Xb0RgLMhb5O3DH6qJPIbppL6Zwnkdu4nbdrZAyTV3I6ZboB604E/3nh9j3JGKg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710515858; c=relaxed/simple; bh=go1R2ToTinN4grzju22TbQWhnL0nxFJ1qs1x6RpMpZ4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FlnM41InCi+mh0u8YWlPU01EYAlf1fqHsCnsBvVnc9pn9qVTFtvohVFdcEPikAEZ0A9dne3e6SGj43yO+2fQ/Zh+UKgTUGEDRFYjydHM8Zv+Nyvyvqd2HN+sIjKWn+NLRa/cSG1ibTXRv7mrm7Zf5M69tRQDPPcFvYXMBk9QAds= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=L01c2KtI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="L01c2KtI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 313DBC433C7; Fri, 15 Mar 2024 15:17:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710515857; bh=go1R2ToTinN4grzju22TbQWhnL0nxFJ1qs1x6RpMpZ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L01c2KtIz1zf6Ums5BkDsOanMNpNXTuCWcvcFMu3D13yH5or9B7zxEsVYwQxmGWuh uIWDOKqRUgxYL6mN6LYlSHcGxMVH3t7AMe/zLpeZM61tmbyYGrxpdQK0Eq9iSHOTL6 TuGU8vNWQkusaaw84USyVUvnQD3UkWBsoa0jmB5mQEvp/iGQx1hxNbhIqiBovGLsm0 gb5pEg794U0J7jpz7m2VftYhiJJW+qIhk+epeUL9XUiHZkbOuke1RLNm/DNf5hommC urHDVDxUvMhKVRfdQvcUEhQvhXRhFErEmERCSttjJzrIIsOSDUjD3pj5yJQQyM7RUp vEHl3CI+HMFow== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Cc: Antoine Tenart , steffen.klassert@secunet.com, netdev@vger.kernel.org Subject: [PATCH net 4/4] udp: prevent local UDP tunnel packets from being GROed Date: Fri, 15 Mar 2024 16:17:20 +0100 Message-ID: <20240315151722.119628-5-atenart@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240315151722.119628-1-atenart@kernel.org> References: <20240315151722.119628-1-atenart@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org GRO has a fundamental issue with UDP tunnel packets as it can't detect those in a foolproof way and GRO could happen before they reach the tunnel endpoint. Previous commits have fixed issues when UDP tunnel packets come from a remote host, but if those packets are issued locally they could run into checksum issues. If the inner packet has a partial checksum the information will be lost in the GRO logic, either in udp4/6_gro_complete or in udp_gro_complete_segment and packets will have an invalid checksum when leaving the host. Prevent local UDP tunnel packets from ever being GROed at the outer UDP level. Due to skb->encapsulation being wrongly used in some drivers this is actually only preventing UDP tunnel packets with a partial checksum to be GROed (see iptunnel_handle_offloads) but those were also the packets triggering issues so in practice this should be sufficient. Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Fixes: 36707061d6ba ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets") Suggested-by: Paolo Abeni Signed-off-by: Antoine Tenart Reviewed-by: Willem de Bruijn --- net/ipv4/udp_offload.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 3263ebcaa3f4..4ea72bd4f6d7 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -559,6 +559,12 @@ struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb, */ NAPI_GRO_CB(skb)->is_flist = 0; if (!sk || !udp_sk(sk)->gro_receive) { + /* If the packet was locally encapsulated in a UDP tunnel that + * wasn't detected above, do not GRO. + */ + if (skb->encapsulation) + goto out; + if (skb->dev->features & NETIF_F_GRO_FRAGLIST) NAPI_GRO_CB(skb)->is_flist = sk ? !udp_test_bit(GRO_ENABLED, sk) : 1;