From patchwork Wed Mar 29 12:38:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Rob Herring (Arm)" X-Patchwork-Id: 13192353 X-Patchwork-Delegate: bhelgaas@google.com 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 479AAC74A5B for ; Wed, 29 Mar 2023 12:39:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229738AbjC2MjF (ORCPT ); Wed, 29 Mar 2023 08:39:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229658AbjC2MjE (ORCPT ); Wed, 29 Mar 2023 08:39:04 -0400 Received: from mail-oi1-f175.google.com (mail-oi1-f175.google.com [209.85.167.175]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DFB319B; Wed, 29 Mar 2023 05:39:03 -0700 (PDT) Received: by mail-oi1-f175.google.com with SMTP id r14so5755032oiw.12; Wed, 29 Mar 2023 05:39:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680093543; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=zuLF4mG8KTV/m4ayMe7Q/gSh3eN9gwA6jaAXiVE/1pM=; b=2RGMcpOHaJKsYVQQw+W8eT9nC1lDaAA15fM+wxOAcrjrqQCUZxgP4jZ6pgRTE/sfUf wyBcvMZsboN2GgTMt6UnnWf4Hl+7N8sHxVXJ5p9kaCRNPkGKyRvP7/Ll+dbbsKmsWdHw ZYFrl2mzB8fPssAertgICyORUqhBlQRP8OamdjA1/fW5/DKmf3s44RhnJqy+Xl+63Wr/ Gy/An2tYX0wBoLz6rN+mYuGjAY+dL4LJtj0PKniM+Z668G47ud/aWn/cBs3kMn3Xt/rj wqaeCJDxG9vzhsttp7IRgd2fc+RvkeSJ3lOSRuHO16KPx1PRvz++KlpLMrXN7l3YIos3 3XZQ== X-Gm-Message-State: AO0yUKW8t9ziPuVtTMtwsmy5zD6FstWRqDZuVPPe9h9hLAagTxvtNqgV DdsK2hNeUuqZnT03hUGplQ== X-Google-Smtp-Source: AK7set/JC4BaXpmgDCIc8Jg7j+gs+I5dpQzu5Z3CYmvb6hPXylNsgQ/UeFQ1u6nzNWI4SZTOCOzcjQ== X-Received: by 2002:a54:440f:0:b0:386:ee2f:86e7 with SMTP id k15-20020a54440f000000b00386ee2f86e7mr8139484oiw.10.1680093542772; Wed, 29 Mar 2023 05:39:02 -0700 (PDT) Received: from robh_at_kernel.org (66-90-144-107.dyn.grandenetworks.net. [66.90.144.107]) by smtp.gmail.com with ESMTPSA id o79-20020a4a2c52000000b0053b8ae294f3sm7711992ooo.11.2023.03.29.05.39.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Mar 2023 05:39:02 -0700 (PDT) Received: (nullmailer pid 2725003 invoked by uid 1000); Wed, 29 Mar 2023 12:39:01 -0000 From: Rob Herring To: Bjorn Helgaas , =?utf-8?q?Pali_Roh=C3=A1r?= Cc: Jon Hunter , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] PCI: Fix use-after-free in pci_bus_release_domain_nr() Date: Wed, 29 Mar 2023 07:38:35 -0500 Message-Id: <20230329123835.2724518-1-robh@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Commit c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()") introduced a use-after-free bug in the bus removal cleanup. The issue was found with kfence: [ 19.285870] ================================================================== [ 19.293351] BUG: KFENCE: use-after-free read in pci_bus_release_domain_nr+0x10/0x70 [ 19.302817] Use-after-free read at 0x000000007f3b80eb (in kfence-#115): [ 19.309677] pci_bus_release_domain_nr+0x10/0x70 [ 19.309691] dw_pcie_host_deinit+0x28/0x78 [ 19.309702] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194] [ 19.309734] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194] [ 19.309752] platform_probe+0x90/0xd8 [ 19.309764] really_probe+0xb8/0x298 [ 19.309777] __driver_probe_device+0x78/0xd8 [ 19.309788] driver_probe_device+0x38/0x120 [ 19.309799] __device_attach_driver+0x94/0xe0 [ 19.309812] bus_for_each_drv+0x70/0xc8 [ 19.309822] __device_attach+0xfc/0x188 [ 19.309833] device_initial_probe+0x10/0x18 [ 19.309844] bus_probe_device+0x94/0xa0 [ 19.309854] deferred_probe_work_func+0x80/0xb8 [ 19.309864] process_one_work+0x1e0/0x348 [ 19.309882] worker_thread+0x48/0x410 [ 19.309891] kthread+0xf4/0x110 [ 19.309904] ret_from_fork+0x10/0x20 [ 19.311457] kfence-#115: 0x00000000063a155a-0x00000000ba698da8, size=1072, cache=kmalloc-2k [ 19.311469] allocated by task 96 on cpu 10 at 19.279323s: [ 19.311562] __kmem_cache_alloc_node+0x260/0x278 [ 19.311571] kmalloc_trace+0x24/0x30 [ 19.311580] pci_alloc_bus+0x24/0xa0 [ 19.311590] pci_register_host_bridge+0x48/0x4b8 [ 19.311601] pci_scan_root_bus_bridge+0xc0/0xe8 [ 19.311613] pci_host_probe+0x18/0xc0 [ 19.311623] dw_pcie_host_init+0x2c0/0x568 [ 19.311630] tegra_pcie_dw_probe+0x610/0xb28 [pcie_tegra194] [ 19.311647] platform_probe+0x90/0xd8 [ 19.311653] really_probe+0xb8/0x298 [ 19.311663] __driver_probe_device+0x78/0xd8 [ 19.311672] driver_probe_device+0x38/0x120 [ 19.311682] __device_attach_driver+0x94/0xe0 [ 19.311694] bus_for_each_drv+0x70/0xc8 [ 19.311702] __device_attach+0xfc/0x188 [ 19.311713] device_initial_probe+0x10/0x18 [ 19.311724] bus_probe_device+0x94/0xa0 [ 19.311733] deferred_probe_work_func+0x80/0xb8 [ 19.311743] process_one_work+0x1e0/0x348 [ 19.311753] worker_thread+0x48/0x410 [ 19.311763] kthread+0xf4/0x110 [ 19.311771] ret_from_fork+0x10/0x20 [ 19.311782] freed by task 96 on cpu 10 at 19.285833s: [ 19.311799] release_pcibus_dev+0x30/0x40 [ 19.311808] device_release+0x30/0x90 [ 19.311814] kobject_put+0xa8/0x120 [ 19.311832] device_unregister+0x20/0x30 [ 19.311839] pci_remove_bus+0x78/0x88 [ 19.311850] pci_remove_root_bus+0x5c/0x98 [ 19.311860] dw_pcie_host_deinit+0x28/0x78 [ 19.311866] tegra_pcie_deinit_controller+0x1c/0x38 [pcie_tegra194] [ 19.311883] tegra_pcie_dw_probe+0x648/0xb28 [pcie_tegra194] [ 19.311900] platform_probe+0x90/0xd8 [ 19.311906] really_probe+0xb8/0x298 [ 19.311916] __driver_probe_device+0x78/0xd8 [ 19.311926] driver_probe_device+0x38/0x120 [ 19.311936] __device_attach_driver+0x94/0xe0 [ 19.311947] bus_for_each_drv+0x70/0xc8 [ 19.311956] __device_attach+0xfc/0x188 [ 19.311966] device_initial_probe+0x10/0x18 [ 19.311976] bus_probe_device+0x94/0xa0 [ 19.311985] deferred_probe_work_func+0x80/0xb8 [ 19.311995] process_one_work+0x1e0/0x348 [ 19.312005] worker_thread+0x48/0x410 [ 19.312014] kthread+0xf4/0x110 [ 19.312022] ret_from_fork+0x10/0x20 [ 19.313579] CPU: 10 PID: 96 Comm: kworker/u24:2 Not tainted 6.2.0 #4 [ 19.320171] Hardware name: /, BIOS 1.0-d7fb19b 08/10/2022 [ 19.325852] Workqueue: events_unbound deferred_probe_work_func [ 19.331919] ================================================================== The stack trace is a bit misleading as dw_pcie_host_deinit() doesn't directly call pci_bus_release_domain_nr(). The issue turns out to be in pci_remove_root_bus() which first calls pci_remove_bus() which frees the struct pci_bus when its struct device is released. Then pci_bus_release_domain_nr() is called and accesses the freed struct pci_bus. Reordering these fixes the issue. Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()") Reported-by: Jon Hunter Tested-by: Jon Hunter Cc: Pali Rohár Signed-off-by: Rob Herring Reviewed-by: Kuppuswamy Sathyanarayanan --- drivers/pci/remove.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index 0145aef1b930..22d39e12b236 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -157,8 +157,6 @@ void pci_remove_root_bus(struct pci_bus *bus) list_for_each_entry_safe(child, tmp, &bus->devices, bus_list) pci_remove_bus_device(child); - pci_remove_bus(bus); - host_bridge->bus = NULL; #ifdef CONFIG_PCI_DOMAINS_GENERIC /* Release domain_nr if it was dynamically allocated */ @@ -166,6 +164,9 @@ void pci_remove_root_bus(struct pci_bus *bus) pci_bus_release_domain_nr(bus, host_bridge->dev.parent); #endif + pci_remove_bus(bus); + host_bridge->bus = NULL; + /* remove the host bridge */ device_del(&host_bridge->dev); }