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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8699C433FE for ; Mon, 11 Oct 2021 13:09:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE36D60F22 for ; Mon, 11 Oct 2021 13:09:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236815AbhJKNLe (ORCPT ); Mon, 11 Oct 2021 09:11:34 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:28916 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236807AbhJKNLd (ORCPT ); Mon, 11 Oct 2021 09:11:33 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4HSfCh6mvszbn4k; Mon, 11 Oct 2021 21:05:04 +0800 (CST) Received: from kwepemm600001.china.huawei.com (7.193.23.3) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Mon, 11 Oct 2021 21:09:29 +0800 Received: from huawei.com (10.175.104.82) by kwepemm600001.china.huawei.com (7.193.23.3) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Mon, 11 Oct 2021 21:09:28 +0800 From: Wang Hai To: , , , , , <21cnbao@gmail.com>, CC: , Subject: [PATCH v2] PCI/MSI: fix page fault when msi_populate_sysfs() failed Date: Mon, 11 Oct 2021 21:08:37 +0800 Message-ID: <20211011130837.766323-1-wanghai38@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.104.82] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600001.china.huawei.com (7.193.23.3) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I got a page fault report when doing fault injection test: BUG: unable to handle page fault for address: fffffffffffffff4 ... RIP: 0010:sysfs_remove_groups+0x25/0x60 ... Call Trace: msi_destroy_sysfs+0x30/0xa0 free_msi_irqs+0x11d/0x1b0 __pci_enable_msix_range+0x67f/0x760 pci_alloc_irq_vectors_affinity+0xe7/0x170 vp_find_vqs_msix+0x129/0x560 vp_find_vqs+0x52/0x230 vp_modern_find_vqs+0x47/0xb0 p9_virtio_probe+0xa1/0x460 [9pnet_virtio] ... entry_SYSCALL_64_after_hwframe+0x44/0xae When populating msi_irqs sysfs failed in msi_capability_init() or msix_capability_init(), dev->msi_irq_groups will point to ERR_PTR(...). This will cause a page fault when destroying the wrong dev->msi_irq_groups in free_msi_irqs(). Define a temp variable and assign it to dev->msi_irq_groups if the temp variable is not PTR_ERR. Fixes: 2f170814bdd2 ("genirq/msi: Move MSI sysfs handling from PCI to MSI core") Reported-by: Hulk Robot Signed-off-by: Wang Hai Acked-by: Barry Song --- v1->v2: introduce temporary variable 'groups' drivers/pci/msi.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 0099a00af361..4b4792940e86 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -535,6 +535,7 @@ static int msi_verify_entries(struct pci_dev *dev) static int msi_capability_init(struct pci_dev *dev, int nvec, struct irq_affinity *affd) { + const struct attribute_group **groups; struct msi_desc *entry; int ret; @@ -558,12 +559,14 @@ static int msi_capability_init(struct pci_dev *dev, int nvec, if (ret) goto err; - dev->msi_irq_groups = msi_populate_sysfs(&dev->dev); - if (IS_ERR(dev->msi_irq_groups)) { - ret = PTR_ERR(dev->msi_irq_groups); + groups = msi_populate_sysfs(&dev->dev); + if (IS_ERR(groups)) { + ret = PTR_ERR(groups); goto err; } + dev->msi_irq_groups = groups; + /* Set MSI enabled bits */ pci_intx_for_msi(dev, 0); pci_msi_set_enable(dev, 1); @@ -691,6 +694,7 @@ static void msix_mask_all(void __iomem *base, int tsize) static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, int nvec, struct irq_affinity *affd) { + const struct attribute_group **groups; void __iomem *base; int ret, tsize; u16 control; @@ -730,12 +734,14 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, msix_update_entries(dev, entries); - dev->msi_irq_groups = msi_populate_sysfs(&dev->dev); - if (IS_ERR(dev->msi_irq_groups)) { - ret = PTR_ERR(dev->msi_irq_groups); + groups = msi_populate_sysfs(&dev->dev); + if (IS_ERR(groups)) { + ret = PTR_ERR(groups); goto out_free; } + dev->msi_irq_groups = groups; + /* Set MSI-X enabled bits and unmask the function */ pci_intx_for_msi(dev, 0); dev->msix_enabled = 1; -- 2.17.1