linux-kernel - [PATCH v2 1/2] vfio iommu type1: Fix size argument to vfio_find

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-next>] [day] [month] [year] [list]

Message-ID: <1481044410-23862-1-git-send-email-kwankhede@nvidia.com>
Date:   Tue, 6 Dec 2016 22:43:30 +0530
From:   Kirti Wankhede <kwankhede@...dia.com>
To:     <alex.williamson@...hat.com>, <pbonzini@...hat.com>,
        <kraxel@...hat.com>, <cjia@...dia.com>
CC:     <qemu-devel@...gnu.org>, <kvm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>,
        Kirti Wankhede <kwankhede@...dia.com>
Subject: [PATCH v2 1/2] vfio iommu type1: Fix size argument to vfio_find_dma() during DMA UNMAP.

vfio_dma keeps track of address range from (dma->iova + 0) to
(dma->iova + dma->size - 1), while vfio_find_dma() search logic looks for
range from (dma->iova + 1) to (dma->iova + dma->size).
In vfio_find_dma(), when the start address is equal to dma->iova and size
is 0, check for the end of search range makes it to take wrong side of
RB-tree. That fails the search even though the address is present in
mapped dma ranges. Due to this, in vfio_dma_do_unmap(), while checking
boundary conditions, size should be set to 1 for verifying start address
of unmap range.
vfio_find_dma() is also used to verify last address in unmap range with
size = 0, but in that case address to be searched is calculated with
size - 1 and so it works correctly.

Signed-off-by: Kirti Wankhede <kwankhede@...dia.com>
Signed-off-by: Neo Jia <cjia@...dia.com>
---
 drivers/vfio/vfio_iommu_type1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index a28fbddb505c..8e9e94ccb2ff 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -826,7 +826,7 @@ again:
 	 * mappings within the range.
 	 */
 	if (iommu->v2) {
-		dma = vfio_find_dma(iommu, unmap->iova, 0);
+		dma = vfio_find_dma(iommu, unmap->iova, 1);
 		if (dma && dma->iova != unmap->iova) {
 			ret = -EINVAL;
 			goto unlock;
-- 
2.7.0