linux-kernel - [PATCH 5.4 093/123] iommu/dma: Fix MSI reservation allocation

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]

Date:   Tue, 17 Mar 2020 11:55:20 +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, Marc Zyngier <maz@...nel.org>,
        Eric Auger <eric.auger@...hat.com>,
        Robin Murphy <robin.murphy@....com>,
        Joerg Roedel <jroedel@...e.de>, Will Deacon <will@...nel.org>
Subject: [PATCH 5.4 093/123] iommu/dma: Fix MSI reservation allocation

From: Marc Zyngier <maz@...nel.org>

commit 65ac74f1de3334852fb7d9b1b430fa5a06524276 upstream.

The way cookie_init_hw_msi_region() allocates the iommu_dma_msi_page
structures doesn't match the way iommu_put_dma_cookie() frees them.

The former performs a single allocation of all the required structures,
while the latter tries to free them one at a time. It doesn't quite
work for the main use case (the GICv3 ITS where the range is 64kB)
when the base granule size is 4kB.

This leads to a nice slab corruption on teardown, which is easily
observable by simply creating a VF on a SRIOV-capable device, and
tearing it down immediately (no need to even make use of it).
Fortunately, this only affects systems where the ITS isn't translated
by the SMMU, which are both rare and non-standard.

Fix it by allocating iommu_dma_msi_page structures one at a time.

Fixes: 7c1b058c8b5a3 ("iommu/dma: Handle IOMMU API reserved regions")
Signed-off-by: Marc Zyngier <maz@...nel.org>
Reviewed-by: Eric Auger <eric.auger@...hat.com>
Cc: Robin Murphy <robin.murphy@....com>
Cc: Joerg Roedel <jroedel@...e.de>
Cc: Will Deacon <will@...nel.org>
Cc: stable@...r.kernel.org
Reviewed-by: Robin Murphy <robin.murphy@....com>
Signed-off-by: Joerg Roedel <jroedel@...e.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/iommu/dma-iommu.c |   16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -176,15 +176,15 @@ static int cookie_init_hw_msi_region(str
 	start -= iova_offset(iovad, start);
 	num_pages = iova_align(iovad, end - start) >> iova_shift(iovad);
 
-	msi_page = kcalloc(num_pages, sizeof(*msi_page), GFP_KERNEL);
-	if (!msi_page)
-		return -ENOMEM;
-
 	for (i = 0; i < num_pages; i++) {
-		msi_page[i].phys = start;
-		msi_page[i].iova = start;
-		INIT_LIST_HEAD(&msi_page[i].list);
-		list_add(&msi_page[i].list, &cookie->msi_page_list);
+		msi_page = kmalloc(sizeof(*msi_page), GFP_KERNEL);
+		if (!msi_page)
+			return -ENOMEM;
+
+		msi_page->phys = start;
+		msi_page->iova = start;
+		INIT_LIST_HEAD(&msi_page->list);
+		list_add(&msi_page->list, &cookie->msi_page_list);
 		start += iovad->granule;
 	}