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 smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 31E36C433F5 for ; Fri, 22 Apr 2022 22:36:05 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id BAE9B82512; Fri, 22 Apr 2022 22:36:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id TJb_CsSRN2lY; Fri, 22 Apr 2022 22:36:03 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp1.osuosl.org (Postfix) with ESMTPS id 60E3C809E7; Fri, 22 Apr 2022 22:36:03 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 39893C0039; Fri, 22 Apr 2022 22:36:03 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [IPv6:2605:bc80:3010::138]) by lists.linuxfoundation.org (Postfix) with ESMTP id A8F2EC002D for ; Fri, 22 Apr 2022 22:36:02 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 8FAC9809E7 for ; Fri, 22 Apr 2022 22:36:02 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8YpbXt0DxpQr for ; Fri, 22 Apr 2022 22:35:58 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) by smtp1.osuosl.org (Postfix) with ESMTPS id 727E9809F6 for ; Fri, 22 Apr 2022 22:35:57 +0000 (UTC) X-UUID: cf57d261ad4a403688e2da312284f880-20220423 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.4, REQID:7e0e9f8f-9cbe-4c41-8c2a-c8b00d92214d, OB:0, LO B:0,IP:0,URL:0,TC:0,Content:-20,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,AC TION:release,TS:-20 X-CID-META: VersionHash:faefae9, CLOUDID:b822d2ef-06b0-4305-bfbf-554bfc9d151a, C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,File:nil,QS:0,BEC:nil X-UUID: cf57d261ad4a403688e2da312284f880-20220423 Received: from mtkexhb01.mediatek.inc [(172.21.101.102)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 703574240; Sat, 23 Apr 2022 06:35:52 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 23 Apr 2022 06:35:52 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 23 Apr 2022 06:35:51 +0800 To: Yong Wu , Joerg Roedel , Will Deacon , Matthias Brugger , Mauro Carvalho Chehab , Hans Verkuil , AngeloGioacchino Del Regno Subject: [PATCH] iommu/mediatek: fix NULL pointer dereference when printing dev_name Date: Sat, 23 Apr 2022 06:35:48 +0800 Message-ID: <20220422223549.4173-1-miles.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N Cc: Joerg Roedel , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Miles Chen , linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Miles Chen via iommu Reply-To: Miles Chen Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" 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 the kernel crashes when we try to print dev_name(larbdev). Fix it by adding a NULL pointer check before device_link_add/device_link_remove. 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 [ 18.190247][ T301] Mem abort info: [ 18.190255][ T301] ESR = 0x96000005 [ 18.190263][ T301] EC = 0x25: DABT (current EL), IL = 32 bits [ 18.192142][ T301] SET = 0, FnV = 0 [ 18.192151][ T301] EA = 0, S1PTW = 0 [ 18.194710][ T301] FSC = 0x05: level 1 translation fault [ 18.195424][ T301] Data abort info: [ 18.195888][ T301] ISV = 0, ISS = 0x00000005 [ 18.196500][ T301] CM = 0, WnR = 0 [ 18.196977][ T301] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104f9e000 [ 18.197889][ T301] [0000000000000050] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 18.199220][ T301] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 18.343152][ T301] Kernel Offset: 0x1444080000 from 0xffffffc008000000 [ 18.343988][ T301] PHYS_OFFSET: 0x40000000 [ 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] [ 18.369840][ T301] __iommu_probe_device+0x12c/0x358 [ 18.370880][ T301] iommu_probe_device+0x3c/0x31c [ 18.372026][ T301] of_iommu_configure+0x200/0x274 [ 18.373587][ T301] of_dma_configure_id+0x1b8/0x230 [ 18.375200][ T301] platform_dma_configure+0x24/0x3c [ 18.376456][ T301] really_probe+0x110/0x504 [ 18.376464][ T301] __driver_probe_device+0xb4/0x188 [ 18.376472][ T301] driver_probe_device+0x5c/0x2b8 [ 18.376481][ T301] __driver_attach+0x338/0x42c [ 18.377992][ T301] bus_add_driver+0x218/0x4c8 [ 18.379389][ T301] driver_register+0x84/0x17c [ 18.380580][ T301] __platform_driver_register+0x28/0x38 ... Fixes: 635319a4a744 ("media: iommu/mediatek: Add device_link between the consumer and the larb devices") Signed-off-by: Miles Chen --- drivers/iommu/mtk_iommu.c | 16 ++++++++++------ drivers/iommu/mtk_iommu_v1.c | 16 ++++++++++------ 2 files changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 6fd75a60abd6..1405502118ca 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -581,10 +581,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -600,8 +602,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = MTK_M4U_TO_LARB(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index ecff800656e6..d46b147afcf0 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -467,10 +467,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -501,8 +503,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = mt2701_m4u_to_larb(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } -- 2.18.0 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DE3A5C433F5 for ; Fri, 22 Apr 2022 22:36:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; 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Fri, 22 Apr 2022 15:35:55 -0700 Received: from mtkmbs07n1.mediatek.inc (172.21.101.16) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 22 Apr 2022 15:35:53 -0700 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 23 Apr 2022 06:35:52 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 23 Apr 2022 06:35:51 +0800 From: Miles Chen To: Yong Wu , Joerg Roedel , "Will Deacon" , Matthias Brugger , "Mauro Carvalho Chehab" , Hans Verkuil , AngeloGioacchino Del Regno CC: Miles Chen , Joerg Roedel , , , , Subject: [PATCH] iommu/mediatek: fix NULL pointer dereference when printing dev_name Date: Sat, 23 Apr 2022 06:35:48 +0800 Message-ID: <20220422223549.4173-1-miles.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220422_153601_381979_15C6B41D X-CRM114-Status: GOOD ( 14.13 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org 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 the kernel crashes when we try to print dev_name(larbdev). Fix it by adding a NULL pointer check before device_link_add/device_link_remove. 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 [ 18.190247][ T301] Mem abort info: [ 18.190255][ T301] ESR = 0x96000005 [ 18.190263][ T301] EC = 0x25: DABT (current EL), IL = 32 bits [ 18.192142][ T301] SET = 0, FnV = 0 [ 18.192151][ T301] EA = 0, S1PTW = 0 [ 18.194710][ T301] FSC = 0x05: level 1 translation fault [ 18.195424][ T301] Data abort info: [ 18.195888][ T301] ISV = 0, ISS = 0x00000005 [ 18.196500][ T301] CM = 0, WnR = 0 [ 18.196977][ T301] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104f9e000 [ 18.197889][ T301] [0000000000000050] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 18.199220][ T301] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 18.343152][ T301] Kernel Offset: 0x1444080000 from 0xffffffc008000000 [ 18.343988][ T301] PHYS_OFFSET: 0x40000000 [ 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] [ 18.369840][ T301] __iommu_probe_device+0x12c/0x358 [ 18.370880][ T301] iommu_probe_device+0x3c/0x31c [ 18.372026][ T301] of_iommu_configure+0x200/0x274 [ 18.373587][ T301] of_dma_configure_id+0x1b8/0x230 [ 18.375200][ T301] platform_dma_configure+0x24/0x3c [ 18.376456][ T301] really_probe+0x110/0x504 [ 18.376464][ T301] __driver_probe_device+0xb4/0x188 [ 18.376472][ T301] driver_probe_device+0x5c/0x2b8 [ 18.376481][ T301] __driver_attach+0x338/0x42c [ 18.377992][ T301] bus_add_driver+0x218/0x4c8 [ 18.379389][ T301] driver_register+0x84/0x17c [ 18.380580][ T301] __platform_driver_register+0x28/0x38 ... Fixes: 635319a4a744 ("media: iommu/mediatek: Add device_link between the consumer and the larb devices") Signed-off-by: Miles Chen --- drivers/iommu/mtk_iommu.c | 16 ++++++++++------ drivers/iommu/mtk_iommu_v1.c | 16 ++++++++++------ 2 files changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 6fd75a60abd6..1405502118ca 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -581,10 +581,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -600,8 +602,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = MTK_M4U_TO_LARB(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index ecff800656e6..d46b147afcf0 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -467,10 +467,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -501,8 +503,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = mt2701_m4u_to_larb(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } -- 2.18.0 _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 035F7C433EF for ; Fri, 22 Apr 2022 22:37:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; 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Fri, 22 Apr 2022 15:35:55 -0700 Received: from mtkmbs07n1.mediatek.inc (172.21.101.16) by MTKMBS62N2.mediatek.inc (172.29.193.42) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 22 Apr 2022 15:35:53 -0700 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Sat, 23 Apr 2022 06:35:52 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 23 Apr 2022 06:35:51 +0800 From: Miles Chen To: Yong Wu , Joerg Roedel , "Will Deacon" , Matthias Brugger , "Mauro Carvalho Chehab" , Hans Verkuil , AngeloGioacchino Del Regno CC: Miles Chen , Joerg Roedel , , , , Subject: [PATCH] iommu/mediatek: fix NULL pointer dereference when printing dev_name Date: Sat, 23 Apr 2022 06:35:48 +0800 Message-ID: <20220422223549.4173-1-miles.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 X-MTK: N X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220422_153601_381979_15C6B41D X-CRM114-Status: GOOD ( 14.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 the kernel crashes when we try to print dev_name(larbdev). Fix it by adding a NULL pointer check before device_link_add/device_link_remove. 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 [ 18.190247][ T301] Mem abort info: [ 18.190255][ T301] ESR = 0x96000005 [ 18.190263][ T301] EC = 0x25: DABT (current EL), IL = 32 bits [ 18.192142][ T301] SET = 0, FnV = 0 [ 18.192151][ T301] EA = 0, S1PTW = 0 [ 18.194710][ T301] FSC = 0x05: level 1 translation fault [ 18.195424][ T301] Data abort info: [ 18.195888][ T301] ISV = 0, ISS = 0x00000005 [ 18.196500][ T301] CM = 0, WnR = 0 [ 18.196977][ T301] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104f9e000 [ 18.197889][ T301] [0000000000000050] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 18.199220][ T301] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 18.343152][ T301] Kernel Offset: 0x1444080000 from 0xffffffc008000000 [ 18.343988][ T301] PHYS_OFFSET: 0x40000000 [ 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] [ 18.369840][ T301] __iommu_probe_device+0x12c/0x358 [ 18.370880][ T301] iommu_probe_device+0x3c/0x31c [ 18.372026][ T301] of_iommu_configure+0x200/0x274 [ 18.373587][ T301] of_dma_configure_id+0x1b8/0x230 [ 18.375200][ T301] platform_dma_configure+0x24/0x3c [ 18.376456][ T301] really_probe+0x110/0x504 [ 18.376464][ T301] __driver_probe_device+0xb4/0x188 [ 18.376472][ T301] driver_probe_device+0x5c/0x2b8 [ 18.376481][ T301] __driver_attach+0x338/0x42c [ 18.377992][ T301] bus_add_driver+0x218/0x4c8 [ 18.379389][ T301] driver_register+0x84/0x17c [ 18.380580][ T301] __platform_driver_register+0x28/0x38 ... Fixes: 635319a4a744 ("media: iommu/mediatek: Add device_link between the consumer and the larb devices") Signed-off-by: Miles Chen --- drivers/iommu/mtk_iommu.c | 16 ++++++++++------ drivers/iommu/mtk_iommu_v1.c | 16 ++++++++++------ 2 files changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 6fd75a60abd6..1405502118ca 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -581,10 +581,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -600,8 +602,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = MTK_M4U_TO_LARB(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index ecff800656e6..d46b147afcf0 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -467,10 +467,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -501,8 +503,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = mt2701_m4u_to_larb(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } -- 2.18.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 20C81C433F5 for ; Fri, 22 Apr 2022 23:03:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234252AbiDVXGK (ORCPT ); Fri, 22 Apr 2022 19:06:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234150AbiDVXGA (ORCPT ); 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Sat, 23 Apr 2022 06:35:52 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Sat, 23 Apr 2022 06:35:51 +0800 From: Miles Chen To: Yong Wu , Joerg Roedel , Will Deacon , Matthias Brugger , Mauro Carvalho Chehab , Hans Verkuil , AngeloGioacchino Del Regno CC: Miles Chen , Joerg Roedel , , , , Subject: [PATCH] iommu/mediatek: fix NULL pointer dereference when printing dev_name Date: Sat, 23 Apr 2022 06:35:48 +0800 Message-ID: <20220422223549.4173-1-miles.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 the kernel crashes when we try to print dev_name(larbdev). Fix it by adding a NULL pointer check before device_link_add/device_link_remove. 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 [ 18.190247][ T301] Mem abort info: [ 18.190255][ T301] ESR = 0x96000005 [ 18.190263][ T301] EC = 0x25: DABT (current EL), IL = 32 bits [ 18.192142][ T301] SET = 0, FnV = 0 [ 18.192151][ T301] EA = 0, S1PTW = 0 [ 18.194710][ T301] FSC = 0x05: level 1 translation fault [ 18.195424][ T301] Data abort info: [ 18.195888][ T301] ISV = 0, ISS = 0x00000005 [ 18.196500][ T301] CM = 0, WnR = 0 [ 18.196977][ T301] user pgtable: 4k pages, 39-bit VAs, pgdp=0000000104f9e000 [ 18.197889][ T301] [0000000000000050] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 18.199220][ T301] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 18.343152][ T301] Kernel Offset: 0x1444080000 from 0xffffffc008000000 [ 18.343988][ T301] PHYS_OFFSET: 0x40000000 [ 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] [ 18.369840][ T301] __iommu_probe_device+0x12c/0x358 [ 18.370880][ T301] iommu_probe_device+0x3c/0x31c [ 18.372026][ T301] of_iommu_configure+0x200/0x274 [ 18.373587][ T301] of_dma_configure_id+0x1b8/0x230 [ 18.375200][ T301] platform_dma_configure+0x24/0x3c [ 18.376456][ T301] really_probe+0x110/0x504 [ 18.376464][ T301] __driver_probe_device+0xb4/0x188 [ 18.376472][ T301] driver_probe_device+0x5c/0x2b8 [ 18.376481][ T301] __driver_attach+0x338/0x42c [ 18.377992][ T301] bus_add_driver+0x218/0x4c8 [ 18.379389][ T301] driver_register+0x84/0x17c [ 18.380580][ T301] __platform_driver_register+0x28/0x38 ... Fixes: 635319a4a744 ("media: iommu/mediatek: Add device_link between the consumer and the larb devices") Signed-off-by: Miles Chen --- drivers/iommu/mtk_iommu.c | 16 ++++++++++------ drivers/iommu/mtk_iommu_v1.c | 16 ++++++++++------ 2 files changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 6fd75a60abd6..1405502118ca 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -581,10 +581,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -600,8 +602,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = MTK_M4U_TO_LARB(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index ecff800656e6..d46b147afcf0 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -467,10 +467,12 @@ static struct iommu_device *mtk_iommu_probe_device(struct device *dev) } larbdev = data->larb_imu[larbid].dev; - link = device_link_add(dev, larbdev, - DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); - if (!link) - dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + if (larbdev) { + link = device_link_add(dev, larbdev, + DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS); + if (!link) + dev_err(dev, "Unable to link %s\n", dev_name(larbdev)); + } return &data->iommu; } @@ -501,8 +503,10 @@ static void mtk_iommu_release_device(struct device *dev) data = dev_iommu_priv_get(dev); larbid = mt2701_m4u_to_larb(fwspec->ids[0]); - larbdev = data->larb_imu[larbid].dev; - device_link_remove(dev, larbdev); + if (larbdev) { + larbdev = data->larb_imu[larbid].dev; + device_link_remove(dev, larbdev); + } iommu_fwspec_free(dev); } -- 2.18.0