From patchwork Tue Mar 19 20:21:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 1913768 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=jWeNvSW0; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4TzjnM6rXkz23r9 for ; Wed, 20 Mar 2024 07:22:15 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rmfxq-00014T-IM; Tue, 19 Mar 2024 16:21:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rmfxo-00013y-Uy for qemu-devel@nongnu.org; Tue, 19 Mar 2024 16:21:36 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rmfxn-0007X3-Fx for qemu-devel@nongnu.org; Tue, 19 Mar 2024 16:21:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710879694; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EfjufpNx+Y+8+5GtcHEkQkTzbcmUP74wXFDJyQBNVkk=; b=jWeNvSW0QBrd9vDgezbPPFIYmxyTlF431Ht9qUzAcsyXhCZAX0Leqi+kp516iurIDFKer8 g41si3ZV99TAKRnckRkzVA2upSIzkYf6TR8FscCoy0PJLffluyFUe1xivZGuogucWghhJ6 2//WluwaK7HTrRJ/2SWmB0VLr0FR8Mc= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-1-A4cRPEddPCedCuvRqOQNQQ-1; Tue, 19 Mar 2024 16:21:33 -0400 X-MC-Unique: A4cRPEddPCedCuvRqOQNQQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B6A801C05EB6 for ; Tue, 19 Mar 2024 20:21:32 +0000 (UTC) Received: from toolbox.redhat.com (unknown [10.42.28.88]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5F9DA10F53; Tue, 19 Mar 2024 20:21:30 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Cc: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= , =?utf-8?q?M?= =?utf-8?q?arc-Andr=C3=A9_Lureau?= , Paolo Bonzini , Thomas Huth Subject: [PULL 3/8] Revert "chardev/char-socket: Fix TLS io channels sending too much data to the backend" Date: Tue, 19 Mar 2024 20:21:16 +0000 Message-ID: <20240319202121.233130-4-berrange@redhat.com> In-Reply-To: <20240319202121.233130-1-berrange@redhat.com> References: <20240319202121.233130-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.422, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This commit results in unexpected termination of the TLS connection. When 'fd_can_read' returns 0, the code goes on to pass a zero length buffer to qio_channel_read. The TLS impl calls into gnutls_recv() with this zero length buffer, at which point GNUTLS returns an error GNUTLS_E_INVALID_REQUEST. This is treated as fatal by QEMU's TLS code resulting in the connection being torn down by the chardev. Simply skipping the qio_channel_read when the buffer length is zero is also not satisfactory, as it results in a high CPU burn busy loop massively slowing QEMU's functionality. The proper solution is to avoid tcp_chr_read being called at all unless the frontend is able to accept more data. This will be done in a followup commit. This reverts commit 462945cd22d2bcd233401ed3aa167d83a8e35b05 Reviewed-by: Thomas Huth Signed-off-by: Daniel P. Berrangé --- chardev/char-socket.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/chardev/char-socket.c b/chardev/char-socket.c index 2c4dffc0e6..812d7aa38a 100644 --- a/chardev/char-socket.c +++ b/chardev/char-socket.c @@ -496,9 +496,9 @@ static gboolean tcp_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque) s->max_size <= 0) { return TRUE; } - len = tcp_chr_read_poll(opaque); - if (len > sizeof(buf)) { - len = sizeof(buf); + len = sizeof(buf); + if (len > s->max_size) { + len = s->max_size; } size = tcp_chr_recv(chr, (void *)buf, len); if (size == 0 || (size == -1 && errno != EAGAIN)) {