From nobody Thu Nov 28 05:56:13 2024 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2BCCB136671; Fri, 4 Oct 2024 09:05:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728032708; cv=none; b=PRwyK/RArW/isnB/eCXO+vqe/kY7le0hl0J7U/q4YAAfTB/LdlG/7l9N3HSJVtmjsU7dldTUIkusEs6KFqLSoj/9NRg6iMXdt1HhHq3arTKiSnzXw7nCKnzAh1/BJGAvIZeQII/4lR3uTE7Q63qB5zJN/7yEt3Zygx0dPngKSRw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728032708; c=relaxed/simple; bh=ekrJAzQHgmb7SrlgSVzWYYeMB5Dtk+b5F9HcO2t22eE=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=TbSmAkSBeeoqeH/WBdxfMl1HPnR6m5EZBOTkv18uQBI5twxaJfgjrRbojmCRKHG8xI2G7Ero+GU3N64EopeM97LVI7SRpFoUYDP5XMLKnwcMYJNj+1Np/QINR3u5uc+U9++o+8mI8L+wgkD2uSbpxyVBcu0r4l1KqaHCDjJ556o= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=QaRllJzD; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="QaRllJzD" Received: from pps.filterd (m0279863.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 493HxP4Q022359; Fri, 4 Oct 2024 09:04:51 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-type:date:from:message-id:mime-version:subject:to; s= qcppdkim1; bh=TKAMJCGYluAljQZ3DGnwueN7JfG9iy5KF83bzr85e4g=; b=Qa RllJzDxovvPEpYVu5Vf9g0NWU+DPtanMPay77VXJNxG8M/9lQY46RtTAu9zsbwnx 1EeR6aUFuQb4YBGL72W3MnB69Bde2UjnmoDLwr8ylom866YhHJQCjy094qWBjW0i ZPbnw8pr4y1bGl2iGv5Q2GOd9F386G2RVwbusXv9cBUXQJV2gZpcKYS0tV8vDs/j Qdo7l9jF/FaDRxHQG9XsGqpS2ou/Sy++avw0eYTD71yP9Mm5lQQLg0pBZwpFnFpb TCThpYYrec03SggP5tUUlkQMNeV2ppuhcIS1byLLLAPKvVKHhA0nWI6JOoRknI7z Duq5HBy9pl2IHK2tvBhQ== Received: from nasanppmta01.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 42205d9k0e-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 04 Oct 2024 09:04:51 +0000 (GMT) Received: from nasanex01c.na.qualcomm.com (nasanex01c.na.qualcomm.com [10.45.79.139]) by NASANPPMTA01.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 49494oD2015431 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 4 Oct 2024 09:04:50 GMT Received: from hu-pbrahma-hyd.qualcomm.com (10.80.80.8) by nasanex01c.na.qualcomm.com (10.45.79.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Fri, 4 Oct 2024 02:04:45 -0700 From: Pratyush Brahma To: CC: , , , , , , , , , , , , Pratyush Brahma , Prakash Gupta Subject: [PATCH v2] iommu/arm-smmu: Defer probe of clients after smmu device bound Date: Fri, 4 Oct 2024 14:34:28 +0530 Message-ID: <20241004090428.2035-1-quic_pbrahma@quicinc.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01c.na.qualcomm.com (10.45.79.139) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: ckNOfJst3dsdkrxNv-SatKxSmw7sAbLX X-Proofpoint-ORIG-GUID: ckNOfJst3dsdkrxNv-SatKxSmw7sAbLX X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 spamscore=0 phishscore=0 priorityscore=1501 malwarescore=0 impostorscore=0 bulkscore=0 suspectscore=0 mlxlogscore=978 lowpriorityscore=0 adultscore=0 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410040065 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Null pointer dereference occurs due to a race between smmu driver probe and client driver probe, when of_dma_configure() for client is called after the iommu_device_register() for smmu driver probe has executed but before the driver_bound() for smmu driver has been called. Following is how the race occurs: T1:Smmu device probe T2: Client device probe really_probe() arm_smmu_device_probe() iommu_device_register() really_probe() platform_dma_configure() of_dma_configure() of_dma_configure_id() of_iommu_configure() iommu_probe_device() iommu_init_device() arm_smmu_probe_device() arm_smmu_get_by_fwnode() driver_find_device_by_fwnode() driver_find_device() next_device() klist_next() /* null ptr assigned to smmu */ /* null ptr dereference while smmu->streamid_mask */ driver_bound() klist_add_tail() When this null smmu pointer is dereferenced later in arm_smmu_probe_device, the device crashes. Fix this by deferring the probe of the client device until the smmu device has bound to the arm smmu driver. Fixes: 021bb8420d44 ("iommu/arm-smmu: Wire up generic configuration support= ") Cc: stable@vger.kernel.org Co-developed-by: Prakash Gupta Signed-off-by: Prakash Gupta Signed-off-by: Pratyush Brahma --- Changes in v2: Fix kernel test robot warning Add stable kernel list in cc Link to v1: https://lore.kernel.org/all/20241001055633.21062-1-quic_pbrahm= a@quicinc.com/ drivers/iommu/arm/arm-smmu/arm-smmu.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-= smmu/arm-smmu.c index 723273440c21..7c778b7eb8c8 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -1437,6 +1437,9 @@ static struct iommu_device *arm_smmu_probe_device(str= uct device *dev) goto out_free; } else { smmu =3D arm_smmu_get_by_fwnode(fwspec->iommu_fwnode); + if (!smmu) + return ERR_PTR(dev_err_probe(dev, -EPROBE_DEFER, + "smmu dev has not bound yet\n")); } =20 ret =3D -EINVAL; --=20 2.17.1