Hi Yi,
On 11/5/18 1:21 PM, Liu, Yi L wrote:
Hi Baolu,
From: iommu-boun...@lists.linux-foundation.org [mailto:iommu-
boun...@lists.linux-foundation.org] On Behalf Of Lu Baolu
Sent: Monday, November 5, 2018 10:19 AM
To: Joerg Roedel <j...@8bytes.org>; David Woodhouse <dw...@infradead.org>
Cc: Raj, Ashok <ashok....@intel.com>; linux-ker...@vger.kernel.org;
iommu@lists.linux-foundation.org
Subject: [PATCH 1/1] iommu/vtd: Fix NULL pointer dereference in
prq_event_thread()
When handling page request without pasid event, go to "no_pasid"
branch instead of "bad_req". Otherwise, a NULL pointer deference will happen
there.
Cc: Ashok Raj <ashok....@intel.com>
Cc: Jacob Pan <jacob.jun....@linux.intel.com>
Cc: Sohil Mehta <sohil.me...@intel.com>
Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
---
drivers/iommu/intel-svm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index
db301efe126d..887150907526 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -595,7 +595,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
pr_err("%s: Page request without PASID: %08llx
%08llx\n",
iommu->name, ((unsigned long long *)req)[0],
((unsigned long long *)req)[1]);
- goto bad_req;
+ goto no_pasid;
}
if (!svm || svm->pasid != req->pasid) {
--
I'm afraid it is still necessary to goto "bad_req". The following code behind
"bad_req" will trigger fault_cb registered by in-kernel drivers. It is
reasonable
that PRQ without PASID can be handled by such callbacks. So I would suggest
to keep the existing logic.
A page fault without a pasid is triggered by a DMA transfer without
PASID. It doesn't relate to the SVM functionality hence there's no
@svm or @sdev related to it. It's unnecessary to report it to the
drivers as far as I can see.
Best regards,
Lu Baolu
if (sdev && sdev->ops && sdev->ops->fault_cb) {
int rwxp = (req->rd_req << 3) | (req->wr_req << 2) |
(req->exe_req << 1) | (req->priv_req);
sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr,
req->private, rwxp, result);
}
Thanks,
Yi Liu
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