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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CD79CCA47E for ; Tue, 7 Jun 2022 18:51:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353529AbiFGSt7 (ORCPT ); Tue, 7 Jun 2022 14:49:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58432 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354479AbiFGSrE (ORCPT ); Tue, 7 Jun 2022 14:47:04 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D92A66AFF; Tue, 7 Jun 2022 11:01:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9BA6A617B0; Tue, 7 Jun 2022 18:01:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2B8BC34119; Tue, 7 Jun 2022 18:01:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654624887; bh=qOG8Y18WbTQ5OroftqQAArGQvZPIVLqJFUdTH/Dey4Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Rg/q3B0r4Ma9aIGqBoe6Z0/Bl3gTJc9OSVJUh5P+uLuh/XAH/bmI27b0K/SONSaln uw8qnR7nCxuJWQQS7ZUWfog2gYlGyr2Ve+//Mt44/XjPXT0BlwYRM62eT6+Zbj3gC6 NKxzVzrwMkbam0btqabCTcsAapdFnvUh2IJ4KenM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Robin Murphy , Yong Wu , kernel test robot , Miles Chen , AngeloGioacchino Del Regno , Joerg Roedel , Sasha Levin Subject: [PATCH 5.15 490/667] iommu/mediatek: Fix NULL pointer dereference when printing dev_name Date: Tue, 7 Jun 2022 19:02:35 +0200 Message-Id: <20220607164949.395899818@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164934.766888869@linuxfoundation.org> References: <20220607164934.766888869@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Miles Chen [ Upstream commit de78657e16f41417da9332f09c2d67d100096939 ] When larbdev is NULL (in the case I hit, the node is incorrectly set iommus = <&iommu NUM>), it will cause device_link_add() fail and kernel crashes when we try to print dev_name(larbdev). Let's fail the probe if a larbdev is NULL to avoid invalid inputs from dts. It should work for normal correct setting and avoid the crash caused by my incorrect setting. Error log: [ 18.189042][ T301] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000050 ... [ 18.344519][ T301] pstate: a0400005 (NzCv daif +PAN -UAO) [ 18.345213][ T301] pc : mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu] [ 18.346050][ T301] lr : mtk_iommu_probe_device+0xd0/0x118 [mtk_iommu] [ 18.346884][ T301] sp : ffffffc00a5635e0 [ 18.347392][ T301] x29: ffffffc00a5635e0 x28: ffffffd44a46c1d8 [ 18.348156][ T301] x27: ffffff80c39a8000 x26: ffffffd44a80cc38 [ 18.348917][ T301] x25: 0000000000000000 x24: ffffffd44a80cc38 [ 18.349677][ T301] x23: ffffffd44e4da4c6 x22: ffffffd44a80cc38 [ 18.350438][ T301] x21: ffffff80cecd1880 x20: 0000000000000000 [ 18.351198][ T301] x19: ffffff80c439f010 x18: ffffffc00a50d0c0 [ 18.351959][ T301] x17: ffffffffffffffff x16: 0000000000000004 [ 18.352719][ T301] x15: 0000000000000004 x14: ffffffd44eb5d420 [ 18.353480][ T301] x13: 0000000000000ad2 x12: 0000000000000003 [ 18.354241][ T301] x11: 00000000fffffad2 x10: c0000000fffffad2 [ 18.355003][ T301] x9 : a0d288d8d7142d00 x8 : a0d288d8d7142d00 [ 18.355763][ T301] x7 : ffffffd44c2bc640 x6 : 0000000000000000 [ 18.356524][ T301] x5 : 0000000000000080 x4 : 0000000000000001 [ 18.357284][ T301] x3 : 0000000000000000 x2 : 0000000000000005 [ 18.358045][ T301] x1 : 0000000000000000 x0 : 0000000000000000 [ 18.360208][ T301] Hardware name: MT6873 (DT) [ 18.360771][ T301] Call trace: [ 18.361168][ T301] dump_backtrace+0xf8/0x1f0 [ 18.361737][ T301] dump_stack_lvl+0xa8/0x11c [ 18.362305][ T301] dump_stack+0x1c/0x2c [ 18.362816][ T301] mrdump_common_die+0x184/0x40c [mrdump] [ 18.363575][ T301] ipanic_die+0x24/0x38 [mrdump] [ 18.364230][ T301] atomic_notifier_call_chain+0x128/0x2b8 [ 18.364937][ T301] die+0x16c/0x568 [ 18.365394][ T301] __do_kernel_fault+0x1e8/0x214 [ 18.365402][ T301] do_page_fault+0xb8/0x678 [ 18.366934][ T301] do_translation_fault+0x48/0x64 [ 18.368645][ T301] do_mem_abort+0x68/0x148 [ 18.368652][ T301] el1_abort+0x40/0x64 [ 18.368660][ T301] el1h_64_sync_handler+0x54/0x88 [ 18.368668][ T301] el1h_64_sync+0x68/0x6c [ 18.368673][ T301] mtk_iommu_probe_device+0xf8/0x118 [mtk_iommu] ... Cc: Robin Murphy Cc: Yong Wu Reported-by: kernel test robot Fixes: 635319a4a744 ("media: iommu/mediatek: Add device_link between the consumer and the larb devices") Signed-off-by: Miles Chen Reviewed-by: Yong Wu Reviewed-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20220505132731.21628-1-miles.chen@mediatek.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/mtk_iommu.c | 6 ++++++ drivers/iommu/mtk_iommu_v1.c | 7 +++++++ 2 files changed, 13 insertions(+) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 9b3ded518f83..2ae46fa6b3de 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -586,6 +586,9 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) * All the ports in each a device should be in the same larbs. */ larbid = MTK_M4U_TO_LARB(fwspec->ids[0]); + if (larbid >= MTK_LARB_NR_MAX) + return ERR_PTR(-EINVAL); + for (i = 1; i < fwspec->num_ids; i++) { larbidx = MTK_M4U_TO_LARB(fwspec->ids[i]); if (larbid != larbidx) { @@ -595,6 +598,9 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } } larbdev = data->larb_imu[larbid].dev; + if (!larbdev) + return ERR_PTR(-EINVAL); + link = device_link_add(dev, larbdev, DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); if (!link) diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index bc7ee90b9373..254530ad6c48 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -80,6 +80,7 @@ /* MTK generation one iommu HW only support 4K size mapping */ #define MT2701_IOMMU_PAGE_SHIFT 12 #define MT2701_IOMMU_PAGE_SIZE (1UL << MT2701_IOMMU_PAGE_SHIFT) +#define MT2701_LARB_NR_MAX 3 /* * MTK m4u support 4GB iova address space, and only support 4K page @@ -457,6 +458,9 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) /* Link the consumer device with the smi-larb device(supplier) */ larbid = mt2701_m4u_to_larb(fwspec->ids[0]); + if (larbid >= MT2701_LARB_NR_MAX) + return ERR_PTR(-EINVAL); + for (idx = 1; idx < fwspec->num_ids; idx++) { larbidx = mt2701_m4u_to_larb(fwspec->ids[idx]); if (larbid != larbidx) { @@ -467,6 +471,9 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } larbdev = data->larb_imu[larbid].dev; + if (!larbdev) + return ERR_PTR(-EINVAL); + link = device_link_add(dev, larbdev, DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); if (!link) -- 2.35.1