Commit 606636dc authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Joerg Roedel
Browse files

iommu/vt-d: Fix out-bounds-warning in intel/svm.c 

Replace a couple of calls to memcpy() with simple assignments in order
to fix the following out-of-bounds warning:

drivers/iommu/intel/svm.c:1198:4: warning: 'memcpy' offset [25, 32] from
    the object at 'desc' is out of the bounds of referenced subobject
    'qw2' with type 'long long unsigned int' at offset 16 [-Warray-bounds]

The problem is that the original code is trying to copy data into a
couple of struct members adjacent to each other in a single call to
memcpy(). This causes a legitimate compiler warning because memcpy()
overruns the length of &desc.qw2 and &resp.qw2, respectively.

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/109


Signed-off-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210414201403.GA392764@embeddedor
Link: https://lore.kernel.org/r/20210610020115.1637656-18-baolu.lu@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 0f4834ab

drivers/iommu/intel/svm.c

+16 −10
Original line number Diff line number Diff line
@@ -870,8 +870,8 @@ static int intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev, 
		 */

		event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;

		event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;

		memcpy(event.fault.prm.private_data, desc->priv_data,

		       sizeof(desc->priv_data));

		event.fault.prm.private_data[0] = desc->priv_data[0];

		event.fault.prm.private_data[1] = desc->priv_data[1];

	} else if (dmar_latency_enabled(iommu, DMAR_LATENCY_PRQ)) {

		/*

		 * If the private data fields are not used by hardware, use it
@@ -910,11 +910,15 @@ static void handle_bad_prq_event(struct intel_iommu *iommu, 
			QI_PGRP_RESP_TYPE;

	desc.qw1 = QI_PGRP_IDX(req->prg_index) |

			QI_PGRP_LPIG(req->lpig);



	if (req->priv_data_present) {

		desc.qw2 = req->priv_data[0];

		desc.qw3 = req->priv_data[1];

	} else {

		desc.qw2 = 0;

		desc.qw3 = 0;

	}



	if (req->priv_data_present)

		memcpy(&desc.qw2, req->priv_data, sizeof(req->priv_data));

	qi_submit_sync(iommu, &desc, 1, 0);

}
@@ -1176,12 +1180,14 @@ int intel_svm_page_response(struct device *dev, 
		desc.qw1 = QI_PGRP_IDX(prm->grpid) | QI_PGRP_LPIG(last_page);

		desc.qw2 = 0;

		desc.qw3 = 0;

		if (private_present)

			memcpy(&desc.qw2, prm->private_data,

			       sizeof(prm->private_data));

		else if (prm->private_data[0])



		if (private_present) {

			desc.qw2 = prm->private_data[0];

			desc.qw3 = prm->private_data[1];

		} else if (prm->private_data[0]) {

			dmar_latency_update(iommu, DMAR_LATENCY_PRQ,

				ktime_to_ns(ktime_get()) - prm->private_data[0]);

		}



		qi_submit_sync(iommu, &desc, 1, 0);

	}