Commit bf708cfb authored Jan 21, 2020 by Jerry Snitselaar Committed by Joerg Roedel Jan 24, 2020

iommu/vt-d: Call __dmar_remove_one_dev_info with valid pointer

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: ae23bfb6 ("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>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

parent def9d278

drivers/iommu/intel-iommu.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -5163,7 +5163,8 @@ static void dmar_remove_one_dev_info(struct device *dev)

		spin_lock_irqsave(&device_domain_lock, flags);
		info = dev->archdata.iommu;
		if (info)
		if (info && info != DEFER_DEVICE_DOMAIN_INFO
		&& info != DUMMY_DEVICE_DOMAIN_INFO)
		__dmar_remove_one_dev_info(info);
		spin_unlock_irqrestore(&device_domain_lock, flags);
		}

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