From patchwork Wed Oct 11 14:20:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Konstantin Kostiuk X-Patchwork-Id: 13417485 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D64C4CD6E76 for ; Wed, 11 Oct 2023 14:21:42 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qqa4r-00020Y-U7; Wed, 11 Oct 2023 10:20:45 -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 1qqa4q-00020P-T2 for qemu-devel@nongnu.org; Wed, 11 Oct 2023 10:20:44 -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 1qqa4p-0001qV-Aq for qemu-devel@nongnu.org; Wed, 11 Oct 2023 10:20:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697034042; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=a5fWOLug7VeTAVZeefrtEofB5vl5fYqqQK0ztW88WoA=; b=E3ix+TiPzh2HNsNsORRo0JLZl6ceJch9JHsNTH+LFT6bWs40mRGNg8qzdlg3sqoDINRGpY FcGCjhZclMz+D47wbyQw8aYdsJc0yKRSlb+vDKVB8k2Gxy2QM8W5dhFgah4FiaurgIVbsS +KsnpKMIkf5Aw3O0fPcCgzDKHm4bSLA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-665-4iwILGv5PqSHgIRmSYwQpg-1; Wed, 11 Oct 2023 10:20:34 -0400 X-MC-Unique: 4iwILGv5PqSHgIRmSYwQpg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 179D58022EA; Wed, 11 Oct 2023 14:20:34 +0000 (UTC) Received: from srv1.redhat.com (unknown [10.45.224.133]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7ACA71005B8E; Wed, 11 Oct 2023 14:20:33 +0000 (UTC) From: Konstantin Kostiuk To: qemu-devel@nongnu.org, Peter Maydell Subject: [PULL 2/3] qga: Fix memory leak when output stream is unused Date: Wed, 11 Oct 2023 17:20:29 +0300 Message-ID: <20231011142030.112018-3-kkostiuk@redhat.com> In-Reply-To: <20231011142030.112018-1-kkostiuk@redhat.com> References: <20231011142030.112018-1-kkostiuk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kkostiuk@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Daniel Xu If capture-output is requested but one of the channels goes unused (eg. we attempt to capture stderr but the command never writes to stderr), we can leak memory. guest_exec_output_watch() is (from what I understand) unconditionally called for both streams if output capture is requested. The first call will always pass the `p->size == p->length` check b/c both values are 0. Then GUEST_EXEC_IO_SIZE bytes will be allocated for the stream. But when we reap the exited process there's a `gei->err.length > 0` check to actually free the buffer. Which does not get run if the command doesn't write to the stream. Fix by making free() unconditional. Reviewed-by: Konstantin Kostiuk Signed-off-by: Daniel Xu Signed-off-by: Konstantin Kostiuk --- qga/commands.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/qga/commands.c b/qga/commands.c index 09c683e263..ce172edd2d 100644 --- a/qga/commands.c +++ b/qga/commands.c @@ -206,15 +206,15 @@ GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **errp) #endif if (gei->out.length > 0) { ges->out_data = g_base64_encode(gei->out.data, gei->out.length); - g_free(gei->out.data); ges->has_out_truncated = gei->out.truncated; } + g_free(gei->out.data); if (gei->err.length > 0) { ges->err_data = g_base64_encode(gei->err.data, gei->err.length); - g_free(gei->err.data); ges->has_err_truncated = gei->err.truncated; } + g_free(gei->err.data); QTAILQ_REMOVE(&guest_exec_state.processes, gei, next); g_free(gei);