From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B368E3D3489 for ; Fri, 29 May 2026 11:12:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780053158; cv=none; b=N8+pJmBXVlHNmDuLmizuERZgSEByU3WGk335pkOPwEjfZS2nx7wb2HrlFHgG2xbOl8f7wgPcKvYRwEVt3MtzeSOmOaRDQ1D4P++UuA/BzocEJTwlseJ0gNiK75P3OkwchaZouAtlry9KLumNRilgtRsJln1zGMD/PIAs9fyeTnc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780053158; c=relaxed/simple; bh=rCPBs6VpzFnSeGV1IQONO9sqLS2eG7RrmNxYtsUNeyw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=oR4xdXxUiqRrhANGkVcxZyrOyzZv35QqrSgJ5w4FXXkwr5q1DSaXZMhBhzUAo6ymVjk8TG54QCbDVO0908EIiwZn4lmTFYjJMx/2la43OlwYTR6hKJXJjbYAt7tYkGg2ZzbxWJdjmEUH3dqAGGoRJZsKpYRCxl4M/WS4uicUWaY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--praan.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=umgvyL2V; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--praan.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="umgvyL2V" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2bf160f7191so6775175ad.3 for ; Fri, 29 May 2026 04:12:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1780053146; x=1780657946; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=junrNZ+TOSSnGGCt6IWg1rMtIZuzEOzNu3RMYtfyWkA=; b=umgvyL2VbhBdv1uUIOXd32DGF3eP4OIddNLAHBFykL6GEkr03rsORqDX1jbu8jj8w4 hvaBhMRaeNi/INMkNmG98rTDMBN369HLb72LrWX/jdd+pQWWHUI3OtWvVagFqLVRf0CT CH2MVZKTw7GHYwqWc6dRgntSgOmHdsfB+BX3TAeagkwqQ65gcrXtAUZK701gEx3YfONb KWcCTe5rn8gF8fxyiy86P+5jf8JummTX3KXMdZ5bZSUaYkWXdsL9P3xWFNbJYIQz9egB +oeHiekzmTEj2flF0Vmxz14bZ/LuUoiRBfmDoa21Bo9YVLeFILAD7Wv1O2ypFA60fRwq +VaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780053146; x=1780657946; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=junrNZ+TOSSnGGCt6IWg1rMtIZuzEOzNu3RMYtfyWkA=; b=JJE1FWRe54bynqnd9ig2sF5zBnwe2GvtAipyAtc07CMccxC7Z0yo46NltMMFZlcspS FA6MkBxBvcXJciGW3J5BDZvNJkcS20kbhKEAQ6Mg0GNuaVaHHlIXWBxsY2G1/bYmI2MD gKCRGiCy/dIB+WbYErHcVSK3C+1PrQt40fMRw3gZ0E3Ob4XrGl18E77YcvEWXrY9MEea Br0zpEzzp2sKAavNN2jsihIwO6YqkBKpppGztdlFAVlztdEJnDSQqoNWMPSdhExsH7aX iAq7w6onhXrC6nmZ9W/15BTpV2tK06+BGtyLMbWJ5qFYe4zfRJz10qxbIOXT1h6rThFi uNLQ== X-Forwarded-Encrypted: i=1; AFNElJ9HZjD/r1W7iYVPyN8HDSnyj3kFlnCEqN7b8LlL2fHBkwMJh1TcAuZIUq85FoiESB0TYqqD0sPW9AjTMAs=@vger.kernel.org X-Gm-Message-State: AOJu0Yywt521Q5mVBYVB+83Lttqy4iFZJAPOtJ0WNYKLK4k3QrIYuJvF DoryzsLjvdGAay8DXUrn042M1oJk6Zsg11ZM6XhHqg98HjF7SOiMO3mZjrtLVgH2F/yi6W//MEF svw== X-Received: from plav20.prod.google.com ([2002:a17:902:f0d4:b0:2bf:1a98:5111]) (user=praan job=prod-delivery.src-stubby-dispatcher) by 2002:a17:902:f551:b0:2be:3850:297e with SMTP id d9443c01a7336-2bf2098933bmr34166025ad.31.1780053145610; Fri, 29 May 2026 04:12:25 -0700 (PDT) Date: Fri, 29 May 2026 11:12:08 +0000 In-Reply-To: <20260529111208.387412-1-praan@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260529111208.387412-1-praan@google.com> X-Mailer: git-send-email 2.54.0.823.g6e5bcc1fc9-goog Message-ID: <20260529111208.387412-7-praan@google.com> Subject: [PATCH v6 6/6] iommu/amd: Fail probe on ATS configuration failure From: Pranjal Shrivastava To: iommu@lists.linux.dev, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Joerg Roedel , Will Deacon , Bjorn Helgaas , David Woodhouse , Lu Baolu , Robin Murphy , Suravee Suthikulpanit , Jason Gunthorpe , Nicolin Chen , David Matlack , Samiullah Khawaja , Daniel Mentz , Pasha Tatashin , Mostafa Saleh , Pranjal Shrivastava Content-Type: text/plain; charset="UTF-8" Update the AMD IOMMU driver to handle ATS configuration and enablement more strictly. Specifically, update the device probe to fail if pci_prepare_ats() returns an error. This ensures that any ATS-capable master reaching the attach phase is guaranteed to have a valid config. Additionally, update pdev_enable_cap_ats() to WARN_ON() if pci_enable_ats fails. Since earlier checks in the probe phase preclude config-related failures, any failure during hardware enablement is considered a kernel bug. Fix a pre-existing Use-After-Free risk by ensuring iommu_ignore_device() is called on all probe failures after iommu_init_device(). Signed-off-by: Pranjal Shrivastava --- drivers/iommu/amd/iommu.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 84cad43dc188..b74c4504bee3 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -570,10 +570,16 @@ static inline int pdev_enable_cap_ats(struct pci_dev *pdev) if (amd_iommu_iotlb_sup && (dev_data->flags & AMD_IOMMU_DEVICE_FLAG_ATS_SUP)) { ret = pci_enable_ats(pdev, PAGE_SHIFT); - if (!ret) { - dev_data->ats_enabled = 1; - dev_data->ats_qdep = pci_ats_queue_depth(pdev); - } + /* + * pci_enable_ats() should not fail here because earlier checks + * have already verified support and configuration. + */ + if (WARN_ON(ret)) + return ret; + + dev_data->ats_enabled = 1; + dev_data->ats_qdep = pci_ats_queue_depth(pdev); + ret = 0; } return ret; @@ -2502,10 +2508,22 @@ static struct iommu_device *amd_iommu_probe_device(struct device *dev) else dev_data->max_irqs = MAX_IRQS_PER_TABLE_512; - if (dev_is_pci(dev)) - pci_prepare_ats(to_pci_dev(dev), PAGE_SHIFT); + if (dev_is_pci(dev)) { + struct pci_dev *pdev = to_pci_dev(dev); + + if (pci_ats_supported(pdev)) { + ret = pci_prepare_ats(pdev, PAGE_SHIFT); + if (ret) { + iommu_dev = ERR_PTR(ret); + goto out_err; + } + } + } out_err: + if (IS_ERR(iommu_dev)) + iommu_ignore_device(iommu, dev); + return iommu_dev; } -- 2.54.0.823.g6e5bcc1fc9-goog