linux-kernel - [PATCH 5.16 126/186] iommu/amd: Fix I/O page table memory leak

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Message-Id: <20220307091657.603212231@linuxfoundation.org>
Date:   Mon,  7 Mar 2022 10:19:24 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Joerg Roedel <joro@...tes.org>,
        Daniel Jordan <daniel.m.jordan@...cle.com>,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
        Joerg Roedel <jroedel@...e.de>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.16 126/186] iommu/amd: Fix I/O page table memory leak

From: Suravee Suthikulpanit <suravee.suthikulpanit@....com>

[ Upstream commit 6b0b2d9a6a308bcd9300c2d83000a82812c56cea ]

The current logic updates the I/O page table mode for the domain
before calling the logic to free memory used for the page table.
This results in IOMMU page table memory leak, and can be observed
when launching VM w/ pass-through devices.

Fix by freeing the memory used for page table before updating the mode.

Cc: Joerg Roedel <joro@...tes.org>
Reported-by: Daniel Jordan <daniel.m.jordan@...cle.com>
Tested-by: Daniel Jordan <daniel.m.jordan@...cle.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Fixes: e42ba0633064 ("iommu/amd: Restructure code for freeing page table")
Link: https://lore.kernel.org/all/20220118194720.urjgi73b7c3tq2o6@oracle.com/
Link: https://lore.kernel.org/r/20220210154745.11524-1-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@...e.de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/iommu/amd/io_pgtable.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index b1bf4125b0f7..6608d1717574 100644
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -492,18 +492,18 @@ static void v1_free_pgtable(struct io_pgtable *iop)
 
 	dom = container_of(pgtable, struct protection_domain, iop);
 
-	/* Update data structure */
-	amd_iommu_domain_clr_pt_root(dom);
-
-	/* Make changes visible to IOMMUs */
-	amd_iommu_domain_update(dom);
-
 	/* Page-table is not visible to IOMMU anymore, so free it */
 	BUG_ON(pgtable->mode < PAGE_MODE_NONE ||
 	       pgtable->mode > PAGE_MODE_6_LEVEL);
 
 	free_sub_pt(pgtable->root, pgtable->mode, &freelist);
 
+	/* Update data structure */
+	amd_iommu_domain_clr_pt_root(dom);
+
+	/* Make changes visible to IOMMUs */
+	amd_iommu_domain_update(dom);
+
 	put_pages_list(&freelist);
 }
 
-- 
2.34.1