From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: ** X-Spam-Status: No, score=2.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNWANTED_LANGUAGE_BODY autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6BE9C6778A for ; Fri, 6 Jul 2018 00:07:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F206240BD for ; Fri, 6 Jul 2018 00:07:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F206240BD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753637AbeGFAG7 (ORCPT ); Thu, 5 Jul 2018 20:06:59 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:42670 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753251AbeGFAG4 (ORCPT ); Thu, 5 Jul 2018 20:06:56 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EBD6040704BC; Fri, 6 Jul 2018 00:06:55 +0000 (UTC) Received: from gblock2.localdomain (ovpn-12-18.pek2.redhat.com [10.72.12.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0D3CA2166BA9; Fri, 6 Jul 2018 00:06:51 +0000 (UTC) From: xiubli@redhat.com To: gregkh@linuxfoundation.org, hamish.martin@alliedtelesis.co.nz, linux-kernel@vger.kernel.org Cc: jannh@google.com, pkalever@redhat.com, pkarampu@redhat.com, atumball@redhat.com, sabose@redhat.com, mchristi@redhat.com Subject: [PATCH V2 2/2] uio: fix crash after the device is unregistered Date: Thu, 5 Jul 2018 20:06:39 -0400 Message-Id: <1530835599-2234-3-git-send-email-xiubli@redhat.com> In-Reply-To: <1530835599-2234-1-git-send-email-xiubli@redhat.com> References: <1530835599-2234-1-git-send-email-xiubli@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 06 Jul 2018 00:06:55 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 06 Jul 2018 00:06:55 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'xiubli@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiubo Li For the target_core_user use case, after the device is unregistered it maybe still opened in user space, then the kernel will crash, like: [ 251.163692] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 251.163820] IP: [] show_name+0x23/0x40 [uio] [ 251.163965] PGD 8000000062694067 PUD 62696067 PMD 0 [ 251.164097] Oops: 0000 [#1] SMP ... [ 251.165605] e1000 mptscsih mptbase drm_panel_orientation_quirks dm_mirror dm_region_hash dm_log dm_mod [ 251.166014] CPU: 0 PID: 13380 Comm: tcmu-runner Kdump: loaded Not tainted 3.10.0-916.el7.test.x86_64 #1 [ 251.166381] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017 [ 251.166747] task: ffff971eb91db0c0 ti: ffff971e9e384000 task.ti: ffff971e9e384000 [ 251.167137] RIP: 0010:[] [] show_name+0x23/0x40 [uio] [ 251.167563] RSP: 0018:ffff971e9e387dc8 EFLAGS: 00010282 [ 251.167978] RAX: 0000000000000000 RBX: ffff971e9e3f8000 RCX: ffff971eb8368d98 [ 251.168408] RDX: ffff971e9e3f8000 RSI: ffffffffc0738084 RDI: ffff971e9e3f8000 [ 251.168856] RBP: ffff971e9e387dd0 R08: ffff971eb8bc0018 R09: 0000000000000000 [ 251.169296] R10: 0000000000001000 R11: ffffffffa09d444d R12: ffffffffa1076e80 [ 251.169750] R13: ffff971e9e387f18 R14: 0000000000000001 R15: ffff971e9cfb1c80 [ 251.170213] FS: 00007ff37d175880(0000) GS:ffff971ebb600000(0000) knlGS:0000000000000000 [ 251.170693] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 251.171248] CR2: 0000000000000008 CR3: 00000000001f6000 CR4: 00000000003607f0 [ 251.172071] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 251.172640] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 251.173236] Call Trace: [ 251.173789] [] dev_attr_show+0x23/0x60 [ 251.174356] [] ? mutex_lock+0x12/0x2f [ 251.174892] [] sysfs_kf_seq_show+0xcf/0x1f0 [ 251.175433] [] kernfs_seq_show+0x26/0x30 [ 251.175981] [] seq_read+0x110/0x3f0 [ 251.176609] [] kernfs_fop_read+0xf5/0x160 [ 251.177158] [] vfs_read+0x9f/0x170 [ 251.177707] [] SyS_read+0x7f/0xf0 [ 251.178268] [] system_call_fastpath+0x1c/0x21 [ 251.178823] Code: 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 d3 e8 7e 96 56 e0 48 8b 80 d8 02 00 00 48 89 df 48 c7 c6 84 80 73 c0 <48> 8b 50 08 31 c0 e8 e2 67 44 e0 5b 48 98 5d c3 0f 1f 00 66 2e [ 251.180115] RIP [] show_name+0x23/0x40 [uio] [ 251.180820] RSP [ 251.181473] CR2: 0000000000000008 CC: Hamish Martin CC: Mike Christie Signed-off-by: Xiubo Li --- drivers/uio/uio.c | 109 ++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 93 insertions(+), 16 deletions(-) diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 33c3bfe..5fe3ca5 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -215,7 +215,20 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf) { struct uio_device *idev = dev_get_drvdata(dev); - return sprintf(buf, "%s\n", idev->info->name); + int ret; + + mutex_lock(&minor_lock); + if (!idev->info) { + ret = -EINVAL; + dev_err(dev, "the device has been unregistered\n"); + goto out; + } + + ret = sprintf(buf, "%s\n", idev->info->name); + +out: + mutex_unlock(&minor_lock); + return ret; } static DEVICE_ATTR_RO(name); @@ -223,7 +236,20 @@ static ssize_t version_show(struct device *dev, struct device_attribute *attr, char *buf) { struct uio_device *idev = dev_get_drvdata(dev); - return sprintf(buf, "%s\n", idev->info->version); + int ret; + + mutex_lock(&minor_lock); + if (!idev->info) { + ret = -EINVAL; + dev_err(dev, "the device has been unregistered\n"); + goto out; + } + + ret = sprintf(buf, "%s\n", idev->info->version); + +out: + mutex_unlock(&minor_lock); + return ret; } static DEVICE_ATTR_RO(version); @@ -399,7 +425,12 @@ static void uio_free_minor(struct uio_device *idev) */ void uio_event_notify(struct uio_info *info) { - struct uio_device *idev = info->uio_dev; + struct uio_device *idev; + + if (!info) + return; + + idev = info->uio_dev; atomic_inc(&idev->event); wake_up_interruptible(&idev->wait); @@ -415,8 +446,12 @@ void uio_event_notify(struct uio_info *info) static irqreturn_t uio_interrupt(int irq, void *dev_id) { struct uio_device *idev = (struct uio_device *)dev_id; - irqreturn_t ret = idev->info->handler(irq, idev->info); + irqreturn_t ret; + + if (!idev->info) + return -EINVAL; + ret = idev->info->handler(irq, idev->info); if (ret == IRQ_HANDLED) uio_event_notify(idev->info); @@ -460,6 +495,12 @@ static int uio_open(struct inode *inode, struct file *filep) filep->private_data = listener; mutex_lock(&idev->info_lock); + if (!idev->info) { + mutex_unlock(&idev->info_lock); + ret = -EINVAL; + goto err_alloc_listener; + } + if (idev->info && idev->info->open) ret = idev->info->open(idev->info, inode); mutex_unlock(&idev->info_lock); @@ -591,6 +632,11 @@ static ssize_t uio_write(struct file *filep, const char __user *buf, s32 irq_on; mutex_lock(&idev->info_lock); + if (!idev->info) { + retval = -EINVAL; + goto out; + } + if (!idev->info || !idev->info->irq) { retval = -EIO; goto out; @@ -636,10 +682,20 @@ static vm_fault_t uio_vma_fault(struct vm_fault *vmf) struct page *page; unsigned long offset; void *addr; + int ret = 0; + int mi; - int mi = uio_find_mem_index(vmf->vma); - if (mi < 0) - return VM_FAULT_SIGBUS; + mutex_lock(&idev->info_lock); + if (!idev->info) { + ret = VM_FAULT_SIGBUS; + goto out; + } + + mi = uio_find_mem_index(vmf->vma); + if (mi < 0) { + ret = VM_FAULT_SIGBUS; + goto out; + } /* * We need to subtract mi because userspace uses offset = N*PAGE_SIZE @@ -654,7 +710,11 @@ static vm_fault_t uio_vma_fault(struct vm_fault *vmf) page = vmalloc_to_page(addr); get_page(page); vmf->page = page; - return 0; + +out: + mutex_unlock(&idev->info_lock); + + return ret; } static const struct vm_operations_struct uio_logical_vm_ops = { @@ -679,6 +739,7 @@ static int uio_mmap_physical(struct vm_area_struct *vma) struct uio_device *idev = vma->vm_private_data; int mi = uio_find_mem_index(vma); struct uio_mem *mem; + if (mi < 0) return -EINVAL; mem = idev->info->mem + mi; @@ -720,30 +781,46 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma) vma->vm_private_data = idev; + mutex_lock(&idev->info_lock); + if (!idev->info) { + ret = -EINVAL; + goto out; + } + mi = uio_find_mem_index(vma); - if (mi < 0) - return -EINVAL; + if (mi < 0) { + ret = -EINVAL; + goto out; + } requested_pages = vma_pages(vma); actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK) + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT; - if (requested_pages > actual_pages) - return -EINVAL; + if (requested_pages > actual_pages) { + ret = -EINVAL; + goto out; + } if (idev->info->mmap) { ret = idev->info->mmap(idev->info, vma); - return ret; + goto out; } switch (idev->info->mem[mi].memtype) { case UIO_MEM_PHYS: - return uio_mmap_physical(vma); + ret = uio_mmap_physical(vma); + break; case UIO_MEM_LOGICAL: case UIO_MEM_VIRTUAL: - return uio_mmap_logical(vma); + ret = uio_mmap_logical(vma); + break; default: - return -EINVAL; + ret = -EINVAL; } + +out: + mutex_unlock(&idev->info_lock); + return 0; } static const struct file_operations uio_fops = { -- 1.8.3.1