From patchwork Mon Oct 4 12:53:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 515198 Delivered-To: patch@linaro.org Received: by 2002:adf:fbc8:0:0:0:0:0 with SMTP id d8csp4339293wrs; Mon, 4 Oct 2021 06:17:35 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyGH9a8kSmqyQ9gbND/Xmrs4yWC0M2Cl12VNZROezfTXZ6hoDDGPtnUSg+U9rAE8mdNk186 X-Received: by 2002:a05:600c:4f8d:: with SMTP id n13mr3837220wmq.89.1633353454591; Mon, 04 Oct 2021 06:17:34 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1633353454; cv=none; d=google.com; s=arc-20160816; b=yWtKa+ZiuyvnwVt2BBJVDQtT01kqDncRfQlG3ARI8JGx0i2bVxoPWmp2LELz9kZJUY W00F6tHVY/Oz8dBxET50AMgukwNuGyF8NdYNhIw79EH8abc5hepjUAXaUbE76PivM2HT iZ5hmlhuCBAOySD2C6T6rCh9a0Am3+L2FU1c9iOsJSAYWneDGYCMIOU8RvBkTMbVSWw2 nOAwbKlaMQSSl/kffm7vgJy+NoRLDMALA96YltL0NlIWPTIkhZRNgV+tOtRjw+jVK343 44D2C4vXfBtcCCb0MdT2MQ+d2YzWaMZypXXZ1Du5qGSo96sO6CMoXjJFTf8SGE+q32wW uHWw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=DheFOeKw7xerAdE0qkMK1AhPq1IUC381W2a1QkaL4as=; b=wLqToIl6xAz2Q2QP+gQdgRhNreNyS+/WfFCjWOFIvDxFgS6Iet5jbhOdvqQhOLqxTt JhbXKccF+x+LjKW/IyoSzRmYdhCbxwX7NMdZoaSOeTKfAhzDR471FDskjJsqjpb/908K PFE4RcC+kQR240jjUUYn8FO6i5BbDxMg8lXMhbnOtMjAoaDPchd1PPDLxzoaMcwgeHRH +T+eAsLg3l4qECtIrUpCX88Tpiv/uoTheYxBxSeAZ2+5/dgZs3SLC+72zS0e9vhe/xrJ QDFQS5aX2CR87slbw5eUeAXFCOU0WEh4PFhzjsv0zK02KeFTSt4IbW0CD+B0U1Mky2P2 dLSA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b="Y/JL1bqU"; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id p7si17279473ejl.82.2021.10.04.06.17.34; Mon, 04 Oct 2021 06:17:34 -0700 (PDT) Received-SPF: pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b="Y/JL1bqU"; spf=pass (google.com: domain of stable-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=stable-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236348AbhJDNTR (ORCPT + 11 others); Mon, 4 Oct 2021 09:19:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:53970 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235644AbhJDNSK (ORCPT ); Mon, 4 Oct 2021 09:18:10 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 46B5261401; Mon, 4 Oct 2021 13:07:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633352845; bh=N2rJ718O84x0hLnlf6FP1msC88XuBpJqMlyEEtlJP6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y/JL1bqUczEzim3ccGce9bKQhZ+qjElixbAiESehQrH2cueoDrMy++u4VU+6x2O/b c34ze+zbLGyvjbQFxCLD04v7QQa1HrIy3qo75dMOal0rgYmTGio0da4EomFfOrglDE LR91hlbwjGBzF4sH6IO4JmHkio97/GnR0C3ANAQM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anders Roxell , Rob Herring , Bjorn Helgaas , Lorenzo Pieralisi , Arnd Bergmann , Tyler Hicks Subject: [PATCH 5.4 47/56] PCI: Fix pci_host_bridge struct device release/free handling Date: Mon, 4 Oct 2021 14:53:07 +0200 Message-Id: <20211004125031.486249023@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211004125030.002116402@linuxfoundation.org> References: <20211004125030.002116402@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Rob Herring commit 9885440b16b8fc1dd7275800fd28f56a92f60896 upstream. The PCI code has several paths where the struct pci_host_bridge is freed directly. This is wrong because it contains a struct device which is refcounted and should be freed using put_device(). This can result in use-after-free errors. I think this problem has existed since 2012 with commit 7b5436635800 ("PCI: add generic device into pci_host_bridge struct"). It generally hasn't mattered as most host bridge drivers are still built-in and can't unbind. The problem is a struct device should never be freed directly once device_initialize() is called and a ref is held, but that doesn't happen until pci_register_host_bridge(). There's then a window between allocating the host bridge and pci_register_host_bridge() where kfree should be used. This is fragile and requires callers to do the right thing. To fix this, we need to split device_register() into device_initialize() and device_add() calls, so that the host bridge struct is always freed by using a put_device(). devm_pci_alloc_host_bridge() is using devm_kzalloc() to allocate struct pci_host_bridge which will be freed directly. Instead, we can use a custom devres action to call put_device(). Link: https://lore.kernel.org/r/20200513223859.11295-2-robh@kernel.org Reported-by: Anders Roxell Tested-by: Anders Roxell Signed-off-by: Rob Herring Signed-off-by: Bjorn Helgaas Reviewed-by: Lorenzo Pieralisi Acked-by: Arnd Bergmann [tyhicks: Minor contextual change in pci_init_host_bridge() due to the lack of a native_dpc member in the pci_host_bridge struct. It was added in v5.7 with commit ac1c8e35a326 ("PCI/DPC: Add Error Disconnect Recover (EDR) support")] Signed-off-by: Tyler Hicks Signed-off-by: Greg Kroah-Hartman --- drivers/pci/probe.c | 36 +++++++++++++++++++----------------- drivers/pci/remove.c | 2 +- 2 files changed, 20 insertions(+), 18 deletions(-) --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -564,7 +564,7 @@ static struct pci_bus *pci_alloc_bus(str return b; } -static void devm_pci_release_host_bridge_dev(struct device *dev) +static void pci_release_host_bridge_dev(struct device *dev) { struct pci_host_bridge *bridge = to_pci_host_bridge(dev); @@ -573,12 +573,7 @@ static void devm_pci_release_host_bridge pci_free_resource_list(&bridge->windows); pci_free_resource_list(&bridge->dma_ranges); -} - -static void pci_release_host_bridge_dev(struct device *dev) -{ - devm_pci_release_host_bridge_dev(dev); - kfree(to_pci_host_bridge(dev)); + kfree(bridge); } static void pci_init_host_bridge(struct pci_host_bridge *bridge) @@ -597,6 +592,8 @@ static void pci_init_host_bridge(struct bridge->native_shpc_hotplug = 1; bridge->native_pme = 1; bridge->native_ltr = 1; + + device_initialize(&bridge->dev); } struct pci_host_bridge *pci_alloc_host_bridge(size_t priv) @@ -614,17 +611,25 @@ struct pci_host_bridge *pci_alloc_host_b } EXPORT_SYMBOL(pci_alloc_host_bridge); +static void devm_pci_alloc_host_bridge_release(void *data) +{ + pci_free_host_bridge(data); +} + struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev, size_t priv) { + int ret; struct pci_host_bridge *bridge; - bridge = devm_kzalloc(dev, sizeof(*bridge) + priv, GFP_KERNEL); + bridge = pci_alloc_host_bridge(priv); if (!bridge) return NULL; - pci_init_host_bridge(bridge); - bridge->dev.release = devm_pci_release_host_bridge_dev; + ret = devm_add_action_or_reset(dev, devm_pci_alloc_host_bridge_release, + bridge); + if (ret) + return NULL; return bridge; } @@ -632,10 +637,7 @@ EXPORT_SYMBOL(devm_pci_alloc_host_bridge void pci_free_host_bridge(struct pci_host_bridge *bridge) { - pci_free_resource_list(&bridge->windows); - pci_free_resource_list(&bridge->dma_ranges); - - kfree(bridge); + put_device(&bridge->dev); } EXPORT_SYMBOL(pci_free_host_bridge); @@ -866,7 +868,7 @@ static int pci_register_host_bridge(stru if (err) goto free; - err = device_register(&bridge->dev); + err = device_add(&bridge->dev); if (err) { put_device(&bridge->dev); goto free; @@ -933,7 +935,7 @@ static int pci_register_host_bridge(stru unregister: put_device(&bridge->dev); - device_unregister(&bridge->dev); + device_del(&bridge->dev); free: kfree(bus); @@ -2945,7 +2947,7 @@ struct pci_bus *pci_create_root_bus(stru return bridge->bus; err_out: - kfree(bridge); + put_device(&bridge->dev); return NULL; } EXPORT_SYMBOL_GPL(pci_create_root_bus); --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -160,6 +160,6 @@ void pci_remove_root_bus(struct pci_bus host_bridge->bus = NULL; /* remove the host bridge */ - device_unregister(&host_bridge->dev); + device_del(&host_bridge->dev); } EXPORT_SYMBOL_GPL(pci_remove_root_bus);