* [PATCH v2][next] iommu/vt-d: Fix out-bounds-warning in intel_svm_page_response()
@ 2021-04-14 20:14 Gustavo A. R. Silva
2021-06-09 7:41 ` Lu Baolu
0 siblings, 1 reply; 2+ messages in thread
From: Gustavo A. R. Silva @ 2021-04-14 20:14 UTC (permalink / raw
To: David Woodhouse, Lu Baolu, Joerg Roedel, Will Deacon
Cc: iommu, linux-hardening, linux-kernel, Gustavo A. R. Silva
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: Gustavo A. R. Silva <gustavoars@kernel.org>
---
Changes in v2:
- Fix another instance of this same issue in prq_event_thread().
drivers/iommu/intel/svm.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 5165cea90421..332365ec3195 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -1020,9 +1020,10 @@ static irqreturn_t prq_event_thread(int irq, void *d)
resp.qw2 = 0;
resp.qw3 = 0;
- if (req->priv_data_present)
- memcpy(&resp.qw2, req->priv_data,
- sizeof(req->priv_data));
+ if (req->priv_data_present) {
+ resp.qw2 = req->priv_data[0];
+ resp.qw3 = req->priv_data[1];
+ }
qi_submit_sync(iommu, &resp, 1, 0);
}
prq_advance:
@@ -1194,9 +1195,10 @@ 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));
+ if (private_present) {
+ desc.qw2 = prm->private_data[0];
+ desc.qw3 = prm->private_data[1];
+ }
qi_submit_sync(iommu, &desc, 1, 0);
}
--
2.27.0
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https://lists.linuxfoundation.org/mailman/listinfo/iommu
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2][next] iommu/vt-d: Fix out-bounds-warning in intel_svm_page_response()
2021-04-14 20:14 [PATCH v2][next] iommu/vt-d: Fix out-bounds-warning in intel_svm_page_response() Gustavo A. R. Silva
@ 2021-06-09 7:41 ` Lu Baolu
0 siblings, 0 replies; 2+ messages in thread
From: Lu Baolu @ 2021-06-09 7:41 UTC (permalink / raw
To: Gustavo A. R. Silva, David Woodhouse, Joerg Roedel, Will Deacon
Cc: iommu, linux-hardening, linux-kernel
On 4/15/21 4:14 AM, Gustavo A. R. Silva wrote:
> 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: Gustavo A. R. Silva<gustavoars@kernel.org>
Queued for v5.14. Thanks!
Best regards,
baolu
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iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
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2021-04-14 20:14 [PATCH v2][next] iommu/vt-d: Fix out-bounds-warning in intel_svm_page_response() Gustavo A. R. Silva
2021-06-09 7:41 ` Lu Baolu
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