From patchwork Sun Mar 27 05:35:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiaomeng Tong X-Patchwork-Id: 554810 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 A1E37C433F5 for ; Sun, 27 Mar 2022 05:36:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235150AbiC0Fhq (ORCPT ); Sun, 27 Mar 2022 01:37:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47710 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235162AbiC0Fhn (ORCPT ); Sun, 27 Mar 2022 01:37:43 -0400 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A4FC192B2; Sat, 26 Mar 2022 22:36:05 -0700 (PDT) Received: by mail-pj1-x102a.google.com with SMTP id m22so11165167pja.0; Sat, 26 Mar 2022 22:36:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id; bh=BXdefmByfbS7iadyHNuWA+1dWRCSn9oFrWGYl5Fm5mk=; b=WD/emqxoTCqSinxwNm9zYC0BhVut37NKvVjalaC3AKb8//RwbBJ0HSEAfuKaQ4TRfn 6kwLAZMOADsCvtCO24agk+3gzGKGTzkJYK5VEESmUvDd0AwLk8MOqqqbGIxQADK8aLnO cnQOeYl0dNZheOli0EHPxR4XCURTaCEwk+DA6AttIClrfhjRFRZ7eNgaXmT3Q5TRifxb oWKTyZ27SYlho/bS0fQMj4jMBTHcATU1sYK+99WO7WA4uv1bNod4RcYqMHfWk7DyqCSQ Qc0paAN62/Th0TsFECWtb5Pb6fzEURwe3BBOKcRwTf5utyKHkZHcplpnGv6lEJDDO1pv w6fQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=BXdefmByfbS7iadyHNuWA+1dWRCSn9oFrWGYl5Fm5mk=; b=P2eXbLVIvLcgAalByEPWZnhoFnawXEylRhe0z2noWo4yOrPMGVu/01L3yPcaOqb+XS n1SqcmkSAHLPl9Di1+aIIDsMxqBuNfVuvh1Sarl1pqYXVlMdOMU1DeK+mxaMRIFifULX gt1sPM4rXcN2ti00p6wvuJaN7S1/q9nAcj73OcVtrtaThuR1x+IJ29O4ZsBYkHSpWBTG tfnC6uzoeN1/Cj6ELeBQKQcCG2H+YalibJHjbZouce4LZS0EiVACijYE9dSjoMY+DNHT KpUE1pTYMb05txIn5dF5uviULgt8ecsTXcXyz2UEunX4St20W0lj5XTYCeXe3HN9KwMk C9xQ== X-Gm-Message-State: AOAM530WUB8PQlyswbBb2seSfIdsw0tOnQ2s74swFdUd2RJl8q9uLost yBEg3vfa5tQFcP66qnj6zes= X-Google-Smtp-Source: ABdhPJzLDpKQkrWzztdlJpJD0lzsWQyEl0Qpi9c3Hry9x9AKCEmmWC14C7eZiUH7Vhej5pAm1C+3YQ== X-Received: by 2002:a17:90a:4217:b0:1c7:c203:b4f3 with SMTP id o23-20020a17090a421700b001c7c203b4f3mr18995680pjg.177.1648359364587; Sat, 26 Mar 2022 22:36:04 -0700 (PDT) Received: from localhost.localdomain ([115.220.243.108]) by smtp.googlemail.com with ESMTPSA id u10-20020a63b54a000000b00380ea901cd2sm9296275pgo.6.2022.03.26.22.36.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 26 Mar 2022 22:36:04 -0700 (PDT) From: Xiaomeng Tong To: agross@kernel.org Cc: bjorn.andersson@linaro.org, joro@8bytes.org, will@kernel.org, sricharan@codeaurora.org, linux-arm-msm@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Xiaomeng Tong , stable@vger.kernel.org Subject: [PATCH] iommu: fix an incorrect NULL check on list iterator Date: Sun, 27 Mar 2022 13:35:58 +0800 Message-Id: <20220327053558.2821-1-xiam0nd.tong@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The bug is here: if (!iommu || iommu->dev->of_node != spec->np) { The list iterator value 'iommu' will *always* be set and non-NULL by list_for_each_entry(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element is found (in fact, it will point to a invalid structure object containing HEAD). To fix the bug, run insert_iommu_master(dev, &iommu, spec); unlock and return 0 when found, otherwise unlock and return -ENODEV. Cc: stable@vger.kernel.org Fixes: f78ebca8ff3d6 ("iommu/msm: Add support for generic master bindings") Signed-off-by: Xiaomeng Tong --- drivers/iommu/msm_iommu.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c index 3a38352b603f..1dbb8b0695ec 100644 --- a/drivers/iommu/msm_iommu.c +++ b/drivers/iommu/msm_iommu.c @@ -617,23 +617,17 @@ static int qcom_iommu_of_xlate(struct device *dev, { struct msm_iommu_dev *iommu; unsigned long flags; - int ret = 0; spin_lock_irqsave(&msm_iommu_lock, flags); list_for_each_entry(iommu, &qcom_iommu_devices, dev_node) - if (iommu->dev->of_node == spec->np) - break; - - if (!iommu || iommu->dev->of_node != spec->np) { - ret = -ENODEV; - goto fail; - } - - insert_iommu_master(dev, &iommu, spec); -fail: + if (iommu->dev->of_node == spec->np) { + insert_iommu_master(dev, &iommu, spec); + spin_unlock_irqrestore(&msm_iommu_lock, flags); + return 0; + } spin_unlock_irqrestore(&msm_iommu_lock, flags); - return ret; + return -ENODEV; } irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id)