linux-kernel - [PATCH 3/4] iommu/vt-d: Reject unsupported page request modes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1613683878-89946-4-git-send-email-jacob.jun.pan@linux.intel.com>
Date:   Thu, 18 Feb 2021 13:31:17 -0800
From:   Jacob Pan <jacob.jun.pan@...ux.intel.com>
To:     LKML <linux-kernel@...r.kernel.org>,
        iommu@...ts.linux-foundation.org, Joerg Roedel <joro@...tes.org>,
        "Lu Baolu" <baolu.lu@...ux.intel.com>
Cc:     Yi Liu <yi.l.liu@...el.com>, Raj Ashok <ashok.raj@...el.com>,
        "Tian, Kevin" <kevin.tian@...el.com>, Wu Hao <hao.wu@...el.com>,
        Yi Sun <yi.y.sun@...el.com>, Dave Jiang <dave.jiang@...el.com>,
        Eric Auger <eric.auger@...hat.com>,
        Jean-Philippe Brucker <jean-philippe@...aro.com>,
        Jacob Pan <jacob.jun.pan@...ux.intel.com>
Subject: [PATCH 3/4] iommu/vt-d: Reject unsupported page request modes

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.

Signed-off-by: Jacob Pan <jacob.jun.pan@...ux.intel.com>
---
 drivers/iommu/intel/svm.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 23a1e4f58c54..ff7ae7cc17d5 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -1113,7 +1113,17 @@ 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);
-- 
2.25.1