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Cc:     baolu.lu@linux.intel.com, Joerg Roedel <joro@8bytes.org>,
        David Woodhouse <dwmw2@infradead.org>, stable@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu/vt-d: call __dmar_remove_one_dev_info with valid
 pointer
To:     Jerry Snitselaar <jsnitsel@redhat.com>,
        iommu@lists.linux-foundation.org
References: <20200122003426.16079-1-jsnitsel@redhat.com>
From:   Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <ac036343-18a2-de7e-6bc2-45966f429c16@linux.intel.com>
Date:   Wed, 22 Jan 2020 13:43:43 +0800
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On 1/22/20 8:34 AM, Jerry Snitselaar wrote:
> It is possible for archdata.iommu to be set to
> DEFER_DEVICE_DOMAIN_INFO or DUMMY_DEVICE_DOMAIN_INFO so check for
> those values before calling __dmar_remove_one_dev_info. Without a
> check it can result in a null pointer dereference. This has been seen
> while booting a kdump kernel on an HP dl380 gen9.
> 
> Cc: Joerg Roedel <joro@8bytes.org>
> Cc: Lu Baolu <baolu.lu@linux.intel.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: stable@vger.kernel.org # 5.3+
> Cc: linux-kernel@vger.kernel.org
> Fixes: ae23bfb68f28 ("iommu/vt-d: Detach domain before using a private one")
> Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>

Acked-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu