From patchwork Wed May 13 22:38:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rob Herring (Arm)" X-Patchwork-Id: 1289757 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; 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=kernel.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49MqN74KW4z9sRK for ; Thu, 14 May 2020 08:39:03 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728787AbgEMWjC (ORCPT ); Wed, 13 May 2020 18:39:02 -0400 Received: from mail-oi1-f176.google.com ([209.85.167.176]:41985 "EHLO mail-oi1-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726383AbgEMWjC (ORCPT ); Wed, 13 May 2020 18:39:02 -0400 Received: by mail-oi1-f176.google.com with SMTP id i13so22916087oie.9 for ; Wed, 13 May 2020 15:39:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=YFDjgxs27nYHCHzwO71zxN+I8MJuYDHW9dIJBotLcbA=; b=JhtfCOwRcD6G1dSs524Rbt9Gtc3wzrjCbyQMCRiWQvA7Papbqjmiu5XJ2nZEM7jPok 9yyh1RVw6DJ3Pl7x4/LEzCtudoM5znB8N/v8U9YLnlg5MYv3I7FChYQEYIchFqQz0SGp DtpDpIBmPUzGvbwjO80QP+HElpYyUTcL/k1r+hT+AuFMxQRBAmvFA1kzXNkgQj04TPg5 osyyWY1SWMyBv22f1URjgVFT2Jt3Au1XdK11zGPzMP4ilOag7WLSoGppGvDXlD2McLlV sJctrd/qod9jiIjjc1GLx+YuScgvIT0Vq6K47nj7e2JapHx3I8Xh0B4qSwMdS/7IlUIb ngKg== X-Gm-Message-State: AGi0PuaxsVxbjPSq73xz4vevn9/Y1PltLg2/z2+a2fLl3Gp7N1T3yIul tuvHwUvdv03vCjWQ6DuOWA== X-Google-Smtp-Source: APiQypJciYid00iJK8xn399+omlFBvasWoVGcrtwDb9M/pf8jD1fqoznZc1yh06zMg42thTVXlseug== X-Received: by 2002:aca:ec51:: with SMTP id k78mr29754238oih.114.1589409540953; Wed, 13 May 2020 15:39:00 -0700 (PDT) Received: from xps15.herring.priv (24-155-109-49.dyn.grandenetworks.net. [24.155.109.49]) by smtp.googlemail.com with ESMTPSA id s13sm6406090oic.27.2020.05.13.15.39.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 May 2020 15:39:00 -0700 (PDT) From: Rob Herring To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Lorenzo Pieralisi , Arnd Bergmann Subject: [PATCH 1/2] PCI: Fix pci_register_host_bridge() device_register() error handling Date: Wed, 13 May 2020 17:38:58 -0500 Message-Id: <20200513223859.11295-1-robh@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org If device_register() has an error, we should bail out of pci_register_host_bridge() rather than continuing on. Fixes: 37d6a0a6f470 ("PCI: Add pci_register_host_bridge() interface") Cc: Arnd Bergmann Cc: Bjorn Helgaas Signed-off-by: Rob Herring Reviewed-by: Lorenzo Pieralisi Reviewed-by: Arnd Bergmann --- drivers/pci/probe.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 77b8a145c39b..e21dc71b1907 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -909,9 +909,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) goto free; err = device_register(&bridge->dev); - if (err) + if (err) { put_device(&bridge->dev); - + goto free; + } bus->bridge = get_device(&bridge->dev); device_enable_async_suspend(bus->bridge); pci_set_bus_of_node(bus); From patchwork Wed May 13 22:38:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rob Herring (Arm)" X-Patchwork-Id: 1289758 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; 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=kernel.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49MqN83l8vz9sSd for ; Thu, 14 May 2020 08:39:04 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729342AbgEMWjD (ORCPT ); Wed, 13 May 2020 18:39:03 -0400 Received: from mail-ot1-f65.google.com ([209.85.210.65]:37757 "EHLO mail-ot1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726383AbgEMWjD (ORCPT ); Wed, 13 May 2020 18:39:03 -0400 Received: by mail-ot1-f65.google.com with SMTP id z17so818693oto.4 for ; Wed, 13 May 2020 15:39:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Y/fu8TLz8jMdgWXPjJ647tXyxXzNUWdC9h5Gz1jMuvU=; b=sIqOpDpvSCFABMpYFfa5oUI8I6lgFdyanTemg6INhHX4+3oq7p9Diu1qF2Lf5qEX6a JSbfZrtuwwvVZFFtEq7AAbLyiDtAS81+ghBFGe+LZOkdDBbwwl+5DADopQgpO5mRigli TDuEGLKTNQzdQ/if5OEA01KUd3Rbb0LaV+cBuJrK7s87VdLnRm/qWZMHIXHnsFuQg+Ti QQTfT+AgozOa6rR+tdWKOmt8dutBb3OlCuJ5jZQvgrz8Sv1yz9GOhp4ysfvVAPbjAPRI JA37VYvsZ6HHvDALOu2W5sHrnqW4ZKUtyi2jPGZjnSzEJNgkTSv360AUTPUw6sl3Zsir OZbw== X-Gm-Message-State: AOAM5308D9t2hidZc1eoyG8jb8PLbbYguOgwd9FEnm2Arei2zpQua1x2 qTrXbnVBAAEYUt29iOxlGw== X-Google-Smtp-Source: ABdhPJyUBHCW4ulIK1t15H0Of7z+gix2mM+CaVhZqFvtT83AKz2nxQc8mLsuH+u0RUcgAp7kGzQZoQ== X-Received: by 2002:a05:6830:138c:: with SMTP id d12mr1398056otq.310.1589409542578; Wed, 13 May 2020 15:39:02 -0700 (PDT) Received: from xps15.herring.priv (24-155-109-49.dyn.grandenetworks.net. [24.155.109.49]) by smtp.googlemail.com with ESMTPSA id s13sm6406090oic.27.2020.05.13.15.39.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 May 2020 15:39:01 -0700 (PDT) From: Rob Herring To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Lorenzo Pieralisi , Anders Roxell , Arnd Bergmann Subject: [PATCH 2/2] PCI: Fix pci_host_bridge struct device release/free handling Date: Wed, 13 May 2020 17:38:59 -0500 Message-Id: <20200513223859.11295-2-robh@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200513223859.11295-1-robh@kernel.org> References: <20200513223859.11295-1-robh@kernel.org> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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(). Reported-by: Anders Roxell Cc: Arnd Bergmann Cc: Bjorn Helgaas Signed-off-by: Rob Herring Tested-by: Anders Roxell Reviewed-by: Lorenzo Pieralisi Acked-by: Arnd Bergmann --- drivers/pci/probe.c | 36 +++++++++++++++++++----------------- drivers/pci/remove.c | 2 +- 2 files changed, 20 insertions(+), 18 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index e21dc71b1907..e064ded6fbec 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -565,7 +565,7 @@ static struct pci_bus *pci_alloc_bus(struct pci_bus *parent) 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); @@ -574,12 +574,7 @@ static void devm_pci_release_host_bridge_dev(struct device *dev) 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) @@ -599,6 +594,8 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge) bridge->native_pme = 1; bridge->native_ltr = 1; bridge->native_dpc = 1; + + device_initialize(&bridge->dev); } struct pci_host_bridge *pci_alloc_host_bridge(size_t priv) @@ -616,17 +613,25 @@ struct pci_host_bridge *pci_alloc_host_bridge(size_t priv) } 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; } @@ -634,10 +639,7 @@ 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); @@ -908,7 +910,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) if (err) goto free; - err = device_register(&bridge->dev); + err = device_add(&bridge->dev); if (err) { put_device(&bridge->dev); goto free; @@ -978,7 +980,7 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) unregister: put_device(&bridge->dev); - device_unregister(&bridge->dev); + device_del(&bridge->dev); free: kfree(bus); @@ -2953,7 +2955,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, return bridge->bus; err_out: - kfree(bridge); + put_device(&bridge->dev); return NULL; } EXPORT_SYMBOL_GPL(pci_create_root_bus); diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index e9c6b120cf45..95dec03d9f2a 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -160,6 +160,6 @@ void pci_remove_root_bus(struct pci_bus *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);