Patch "iommu/vt-d: Reject unsupported page request modes" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    iommu/vt-d: Reject unsupported page request modes

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     iommu-vt-d-reject-unsupported-page-request-modes.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4bb873934b2f0b8464a1cd5893aede99491ee76d
Author: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Date:   Tue Mar 2 02:13:59 2021 -0800

    iommu/vt-d: Reject unsupported page request modes
    
    [ Upstream commit 78a523fe73b81b4447beb2d6c78c9fafae24eebb ]
    
    When supervisor/privilige mode SVM is used, we bind init_mm.pgd with
    a supervisor PASID. There should not be any page fault for init_mm.
    Execution request with DMA read is also not supported.
    
    This patch checks PRQ descriptor for both unsupported configurations,
    reject them both with invalid responses.
    
    Fixes: 1c4f88b7f1f92 ("iommu/vt-d: Shared virtual address in scalable mode")
    Acked-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
    Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/1614680040-1989-4-git-send-email-jacob.jun.pan@xxxxxxxxxxxxxxx
    Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index b200a3acc6ed..5c95e9693bf5 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -959,7 +959,17 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 			       ((unsigned long long *)req)[1]);
 			goto no_pasid;
 		}
-
+		/* We shall not receive page request for supervisor SVM */
+		if (req->pm_req && (req->rd_req | req->wr_req)) {
+			pr_err("Unexpected page request in Privilege Mode");
+			/* No need to find the matching sdev as for bad_req */
+			goto no_pasid;
+		}
+		/* DMA read with exec requeset is not supported. */
+		if (req->exe_req && req->rd_req) {
+			pr_err("Execution request not supported\n");
+			goto no_pasid;
+		}
 		if (!svm || svm->pasid != req->pasid) {
 			rcu_read_lock();
 			svm = ioasid_find(NULL, req->pasid, NULL);