From patchwork Tue Jul 25 13:44:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 1812543 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org 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=) 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 4R9JHR4W8xz1yYC for ; Tue, 25 Jul 2023 23:47:15 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qOINS-0006e6-HS; Tue, 25 Jul 2023 09:47:03 -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 1qOIMF-0005Gs-9z; Tue, 25 Jul 2023 09:45:48 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qOIMD-0001HS-Os; Tue, 25 Jul 2023 09:45:47 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 630BC160ED; Tue, 25 Jul 2023 16:45:33 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 81D95194B0; Tue, 25 Jul 2023 16:45:30 +0300 (MSK) Received: (nullmailer pid 3370798 invoked by uid 1000); Tue, 25 Jul 2023 13:45:29 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Avihai Horon , =?utf-8?q?Phi?= =?utf-8?q?lippe_Mathieu-Daud=C3=A9?= , =?utf-8?q?C=C3=A9?= =?utf-8?q?dric_Le_Goater?= , Alex Williamson , Michael Tokarev Subject: [Stable-8.0.4 05/31] vfio: Fix null pointer dereference bug in vfio_bars_finalize() Date: Tue, 25 Jul 2023 16:44:50 +0300 Message-Id: <20230725134517.3370706-5-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, 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 From: Avihai Horon vfio_realize() has the following flow: 1. vfio_bars_prepare() -- sets VFIOBAR->size. 2. msix_early_setup(). 3. vfio_bars_register() -- allocates VFIOBAR->mr. After vfio_bars_prepare() is called msix_early_setup() can fail. If it does fail, vfio_bars_register() is never called and VFIOBAR->mr is not allocated. In this case, vfio_bars_finalize() is called as part of the error flow to free the bars' resources. However, vfio_bars_finalize() calls object_unparent() for VFIOBAR->mr after checking only VFIOBAR->size, and thus we get a null pointer dereference. Fix it by checking VFIOBAR->mr in vfio_bars_finalize(). Fixes: 89d5202edc50 ("vfio/pci: Allow relocating MSI-X MMIO") Signed-off-by: Avihai Horon Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Cédric Le Goater Reviewed-by: Alex Williamson Signed-off-by: Cédric Le Goater (cherry picked from commit 8af87a3ec7e42ff1b9cf75ceee0451c31e34d153) Signed-off-by: Michael Tokarev diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index 4773cc1f2b..53dcb3efaa 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -1752,9 +1752,11 @@ static void vfio_bars_finalize(VFIOPCIDevice *vdev) vfio_bar_quirk_finalize(vdev, i); vfio_region_finalize(&bar->region); - if (bar->size) { + if (bar->mr) { + assert(bar->size); object_unparent(OBJECT(bar->mr)); g_free(bar->mr); + bar->mr = NULL; } }