From patchwork Thu Jul 12 17:33:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Tai X-Patchwork-Id: 943143 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=oracle.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=oracle.com header.i=@oracle.com header.b="ybqZhNtm"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41RNMf4J0Xz9s2M for ; Fri, 13 Jul 2018 03:33:50 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726349AbeGLRoV (ORCPT ); Thu, 12 Jul 2018 13:44:21 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:46644 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725967AbeGLRoV (ORCPT ); Thu, 12 Jul 2018 13:44:21 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w6CHXjr8061683; Thu, 12 Jul 2018 17:33:45 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=5WbBulu24tK3SbP6MoG/AkgMH3T/cvZCHUCh+sZzX2Q=; b=ybqZhNtmm9QqrcOsnxPiE8q/lazQ6B9dkkY2hz5l5K1OR0Slf2WciixUjewf0kKLs3SH 2i69cin/LkSPkQP8zeqv8AWNoBdYA/8nFQvIfg1rGbPLxD77hwfFrdXN4yY8qdTujC9A QuYRwPoIL9JALfK9rCnBAey5RE+zpmip4KVGH5Tx9DSpg3Pr0vyPWSDxkYhEyvDTkf3A lo8UFTazJlZuZAsERVGDxfVPjl/xqaf1/Aig54cWjTiNUHRpapfByP7rWIp4RvtXYQPh RbhtLLjxq5XwsuHvXTkAx+7BfLjP3lLV+0j2cNimfkXU5YkmqU4z0Y2rPNjN8uD77kHM Tw== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by aserp2120.oracle.com with ESMTP id 2k2p7e4s26-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 12 Jul 2018 17:33:45 +0000 Received: from brm-x54-01.us.oracle.com (brm-x54-01.us.oracle.com [10.80.150.34]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w6CHXh50020776; Thu, 12 Jul 2018 17:33:45 GMT From: Thomas Tai To: thomas.tai@oracle.com, bhelgaas@google.com, poza@codeaurora.org Cc: linux-pci@vger.kernel.org Subject: [PATCH V2, 1/1] PCI/AER: fix use-after-free in pcie_do_fatal_recovery Date: Thu, 12 Jul 2018 11:33:43 -0600 Message-Id: <1531416823-17841-2-git-send-email-thomas.tai@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1531416823-17841-1-git-send-email-thomas.tai@oracle.com> References: <1531416823-17841-1-git-send-email-thomas.tai@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8951 signatures=668706 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=672 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807120185 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org When an fatal error is recevied by a non-bridge device, the device is removed from the pci bus and the device structure is freed by pci_stop_and_remove_bus_device(). The freed device structure is used in the subsequence pci_info() to printout the message. It causes a corrupt printout. If slub_debug=FZP is used, it will cause following protection fault after a fatal error is received. general protection fault: 0000 [#1] SMP PTI CPU: 104 PID: 1077 Comm: kworker/104:1 Not tainted 4.18.0-rc1ttai #5 Hardware name: Oracle Corporation ORACLE SERVER X5-4/ASSY,MB WITH TRAY, BIOS 36030500 11/16/2016 Workqueue: events aer_isr RIP: 0010:__dev_printk+0x2e/0x90 Code: 00 55 49 89 d1 48 89 e5 53 48 89 fb 48 83 ec 18 48 85 f6 74 5f 4c 8b 46 50 4d 85 c0 74 2b 48 8b 86 88 00 00 00 48 85 c0 74 25 <48> 8b 08 0f be 7b 01 48 c7 c2 83 d4 71 99 31 c0 83 ef 30 e8 4a ff RSP: 0018:ffffb6b88fa57cf8 EFLAGS: 00010202 RAX: 6b6b6b6b6b6b6b6b RBX: ffffffff996ba720 RCX: 0000000000000000 RDX: ffffb6b88fa57d28 RSI: ffff8c4d7af94128 RDI: ffffffff996ba720 RBP: ffffb6b88fa57d18 R08: 6b6b6b6b6b6b6b6b R09: ffffb6b88fa57d28 R10: ffffffff99baca80 R11: 0000000000000000 R12: ffff8c4d7ae95990 R13: ffff8c2d7a840008 R14: ffff8c4d7af94088 R15: ffff8c4d7af90008 FS: 0000000000000000(0000) GS:ffff8c2d7fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f22c0839000 CR3: 000000136bc0a001 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? pci_bus_add_device+0x4f/0xa0 _dev_info+0x6c/0x90 pcie_do_fatal_recovery+0x1d5/0x230 aer_isr+0x3e5/0x950 ? add_timer_on+0xcc/0x160 process_one_work+0x168/0x370 worker_thread+0x4f/0x3d0 kthread+0x105/0x140 ? max_active_store+0x80/0x80 ? kthread_bind+0x20/0x20 ret_from_fork+0x35/0x40 To fix this issue, pci_dev_get and pci_dev_put is placed at the entry and exit of the function. This way the device structure is free only at the end of the function if needed. Signed-off-by: Thomas Tai --- drivers/pci/pcie/err.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index f7ce0cb..e5decd8 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -288,6 +288,7 @@ void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service) struct pci_dev *pdev, *temp; pci_ers_result_t result; + pci_dev_get(dev); if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) udev = dev; else @@ -329,6 +330,7 @@ void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service) } pci_unlock_rescan_remove(); + pci_dev_put(dev); } /**