From patchwork Tue Mar 26 11:34:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 13603963 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 7335B6CDB6 for ; Tue, 26 Mar 2024 11:34:18 +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=1711452858; cv=none; b=AlRXEKZ7T+sZyR4l5eK3DPVmxPYG+Fnhtxd22hdh0V9lGfGrPMu7b43cwcSXFKgVtLJQBAnd1IOLFy9wcyIf4Qj7BxBWzEZLTYvZ+eKadNHXvAtY6neumgvvA2YgNwejFsShXtBXN+66N8Ea2bcWJTGm3dwJTlzhvnQgg5JsyOc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711452858; c=relaxed/simple; bh=lNZ3GsF+2FDIGqDK/pc65J09dJNN1ybvqZZZwXWhNVs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=c7E8xEpTR2YjbaphcCMmIah6FcR1YZlf2hXk0Ut1sKq4fcAJcvGpJayI3q8j2NjTNUbKj1lOTgleQGGfSdHap6ffR330Ry437zO+O11yIwGJ7WB/+Sg1dICDutKJ3gRekgwI2m8yK6sUDWkhFZmzZ1+Z+K7t0SGE8sMZKcJXEfM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oUczJQ3K; 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="oUczJQ3K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6A89C43601; Tue, 26 Mar 2024 11:34:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711452858; bh=lNZ3GsF+2FDIGqDK/pc65J09dJNN1ybvqZZZwXWhNVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oUczJQ3KZQAH8g5O3nUq/MuoItBMo81KOxqK7O+7oVJO2aArqbkFTTtge0SIJdry0 60Ka34ypjGGO8IlqofrWsuckRoKUgnoCjAhlwn/0auygqQLL5x0/EXhht2Q+340eGF jl1j/h8tu2rI1D6vSU0H2K8de2Ac0lssUsuWCWXBt3s25vi6T15vBgvXegCAPXRw5t AeniVmV91tStojlc5TdiFTrwvXITy3lCnILkPScBXqnBku5a28KKXuBAitbvjsHUC/ ZjCd2m3iILSGtknNSMLJT72eHESoJmpXznLhkcBX+wXCOdRtunkLeurpxxtmkvVxDb rQhO/XXtJVhig== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Cc: Antoine Tenart , steffen.klassert@secunet.com, willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org, Willem de Bruijn Subject: [PATCH net v4 4/5] udp: prevent local UDP tunnel packets from being GROed Date: Tue, 26 Mar 2024 12:34:01 +0100 Message-ID: <20240326113403.397786-5-atenart@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240326113403.397786-1-atenart@kernel.org> References: <20240326113403.397786-1-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 548476d78237..3498dd1d0694 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;