From patchwork Mon Jul 9 23:45:52 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Tai X-Patchwork-Id: 941735 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="x8dcl+mR"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41PhmP4sdwz9s0W for ; Tue, 10 Jul 2018 09:45:57 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932847AbeGIXp4 (ORCPT ); Mon, 9 Jul 2018 19:45:56 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:58980 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933054AbeGIXpz (ORCPT ); Mon, 9 Jul 2018 19:45:55 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w69NiHn3035929; Mon, 9 Jul 2018 23:45:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id; s=corp-2018-07-02; bh=uOSiVcC+HgYPZyFh9nkmgvE4EZIe8WlxnJot0dMnIM4=; b=x8dcl+mRgq5PEjM+Ff1HYmcwPisWdVBfG/MGRHVK4YuF4NFbmHJugVPKGM/Sd0TPlccr rq6hEqZYnfuDQUxp1wid59QVYHuzXv16o1ZBRqXXlQY/C+TZA7VVgcmGdf8o8pluZg3c USNQaBT0w2qEy/ucquic7l5PL43T5doNn/lTSCzm424aiS5CtD+DfmyFKdj/eFtVuf+h n8UZIXa7vQwRgOBUaabMRfq8mewW7OL7DYuzbVibdRjRgA91HWA7gU9AIaEV3GucuoPv Dae0DEzKUiBpoJ6CrqaK2ZL8mCgIj380b48kUYcdEdd3veT073L9tpudG8k0oWsOKTfc Eg== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2120.oracle.com with ESMTP id 2k2p7v7kdh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 09 Jul 2018 23:45:52 +0000 Received: from brm-x54-01.us.oracle.com (brm-x54-01.us.oracle.com [10.80.150.34]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id w69Njq3q019294; Mon, 9 Jul 2018 23:45:52 GMT From: Thomas Tai To: thomas.tai@oracle.com, bhelgaas@google.com, poza@codeaurora.org Cc: linux-pci@vger.kernel.org Subject: [PATCH] PCI/AER: fix use-after-free in pcie_do_fatal_recovery Date: Mon, 9 Jul 2018 17:45:52 -0600 Message-Id: <1531179952-11060-1-git-send-email-thomas.tai@oracle.com> X-Mailer: git-send-email 1.8.3.1 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8949 signatures=668705 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=2 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807090266 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, the driver and device name is stored in a variable before freeing the device to avoid the use-after-free problem. Signed-off-by: Thomas Tai --- drivers/pci/pcie/err.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c index f7ce0cb..66e16de 100644 --- a/drivers/pci/pcie/err.c +++ b/drivers/pci/pcie/err.c @@ -287,6 +287,13 @@ void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service) struct pci_bus *parent; struct pci_dev *pdev, *temp; pci_ers_result_t result; + const char *driver_str; + const char *name_str; + u8 hdr_type = dev->hdr_type; + + /* copy the device driver name and device name for printing purpose */ + driver_str = kstrdup(dev_driver_string(&dev->dev), GFP_KERNEL); + name_str = kstrdup(dev_name(&dev->dev), GFP_KERNEL); if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) udev = dev; @@ -309,7 +316,7 @@ void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service) result = reset_link(udev, service); if ((service == PCIE_PORT_SERVICE_AER) && - (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) { + (hdr_type == PCI_HEADER_TYPE_BRIDGE)) { /* * If the error is reported by a bridge, we think this error * is related to the downstream link of the bridge, so we @@ -322,13 +329,18 @@ void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service) if (result == PCI_ERS_RESULT_RECOVERED) { if (pcie_wait_for_link(udev, true)) pci_rescan_bus(udev->bus); - pci_info(dev, "Device recovery from fatal error successful\n"); + pr_info("%s %s: Device recovery from fatal error successful\n", + driver_str, name_str); } else { pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT); - pci_info(dev, "Device recovery from fatal error failed\n"); + pr_info("%s %s: Device recovery from fatal error failed\n", + driver_str, name_str); } pci_unlock_rescan_remove(); + + kfree(driver_str); + kfree(name_str); } /**