From patchwork Fri Mar 22 11:46:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 13600001 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 99E4C3EA83 for ; Fri, 22 Mar 2024 11:46:39 +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=1711107999; cv=none; b=YKuCMUXNpmlL3CE/wwcUdPaJ+vqKJtQcPfGmgKbeqUDS0ZaeXqHZnZhhPr99pTC2KGKcY/TWvtoEVmy9hSrmNzYZsPg95b9GYxrZMpq6I/gfIo5fOjaz0B1mb9Sfw0S0TFfAqxASsHpJVa6lr71kVPQBGHXwjib3UesWVNQyKHs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711107999; c=relaxed/simple; bh=lNZ3GsF+2FDIGqDK/pc65J09dJNN1ybvqZZZwXWhNVs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tn3/mwLYo96xZ/kzOkk8kHYCytSfRWDzrvRJ6cVB6DFpvNQ1by2JCX/wgHZ3XEYvmBzt3PLrkbhuq+CYnDME7Iby/WnUjsOEGhTNkkgdFAFUPRhOB7FhDFtsqdd2mCJvpSGjWe7EU8BK/hvJmHpL7+NYxrsfyHCfXhuwRd96J6I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TRQg4/9Z; 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="TRQg4/9Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1929C433F1; Fri, 22 Mar 2024 11:46:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711107999; bh=lNZ3GsF+2FDIGqDK/pc65J09dJNN1ybvqZZZwXWhNVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TRQg4/9Z7ELjfF+iw/+w0dnGSUh6pJXiPqoreaOK9gttvaRQDQ0gAnUxMupKMjEo+ eJU+xRcCYFgpicIfORSxAYW2GWv8XvCHR8Cd27ppHnQ8cP80MfXumel/+w0fSsHC2c /Cf0XM+gDkZJgGbQOj2FdE5xZ2CHCdMAcvVXCgYPeaNxHXRYChK2qj/j0icueL8SM8 d9DHw0GMr/nT7j5g3q40Fzrx3dcXagfUGOCQSfYsngjYMzym5aEr2P2TTukrQ8mVRY SQ1Q+omtgk0CEuPKwI+yeWjFrScIqyIvKayQWFaLLWcvVBypuFKNsIJEpc9zyl2+UE doA3LNPWZskRA== 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 v3 4/4] udp: prevent local UDP tunnel packets from being GROed Date: Fri, 22 Mar 2024 12:46:23 +0100 Message-ID: <20240322114624.160306-5-atenart@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240322114624.160306-1-atenart@kernel.org> References: <20240322114624.160306-1-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;