From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: DRI Development <dri-devel@lists.freedesktop.org>,
LKML <linux-kernel@vger.kernel.org>
Cc: kvm@vger.kernel.org, linux-mm@kvack.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org,
linux-s390@vger.kernel.org,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Jason Gunthorpe" <jgg@ziepe.ca>,
"Kees Cook" <keescook@chromium.org>,
"Dan Williams" <dan.j.williams@intel.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"John Hubbard" <jhubbard@nvidia.com>,
"Jérôme Glisse" <jglisse@redhat.com>, "Jan Kara" <jack@suse.cz>,
"Alex Williamson" <alex.williamson@redhat.com>,
"Cornelia Huck" <cohuck@redhat.com>,
"Daniel Vetter" <daniel.vetter@ffwll.com>
Subject: [PATCH v3 11/16] vfio/type1: Mark follow_pfn as unsafe
Date: Wed, 21 Oct 2020 10:56:50 +0200 [thread overview]
Message-ID: <20201021085655.1192025-12-daniel.vetter@ffwll.ch> (raw)
In-Reply-To: <20201021085655.1192025-1-daniel.vetter@ffwll.ch>
The code seems to stuff these pfns into iommu pts (or something like
that, I didn't follow), but there's no mmu_notifier to ensure that
access is synchronized with pte updates.
Hence mark these as unsafe. This means that with
CONFIG_STRICT_FOLLOW_PFN, these will be rejected.
Real fix is to wire up an mmu_notifier ... somehow. Probably means any
invalidate is a fatal fault for this vfio device, but then this
shouldn't ever happen if userspace is reasonable.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.com>
---
drivers/vfio/vfio_iommu_type1.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 5fbf0c1f7433..a4d53f3d0a35 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -421,7 +421,7 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
{
int ret;
- ret = follow_pfn(vma, vaddr, pfn);
+ ret = unsafe_follow_pfn(vma, vaddr, pfn);
if (ret) {
bool unlocked = false;
@@ -435,7 +435,7 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
if (ret)
return ret;
- ret = follow_pfn(vma, vaddr, pfn);
+ ret = unsafe_follow_pfn(vma, vaddr, pfn);
}
return ret;
--
2.28.0
next prev parent reply other threads:[~2020-10-21 8:57 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-21 8:56 [PATCH v3 00/16] follow_pfn and other iomap races Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 01/16] drm/exynos: Stop using frame_vector helpers Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 02/16] drm/exynos: Use FOLL_LONGTERM for g2d cmdlists Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 03/16] misc/habana: Stop using frame_vector helpers Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 04/16] misc/habana: Use FOLL_LONGTERM for userptr Daniel Vetter
2020-10-23 9:12 ` Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 05/16] mm/frame-vector: Use FOLL_LONGTERM Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 06/16] media: videobuf2: Move frame_vector into media subsystem Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 07/16] mm: Close race in generic_access_phys Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 08/16] s390/pci: Remove races against pte updates Daniel Vetter
2020-10-21 9:37 ` Niklas Schnelle
2020-10-21 13:56 ` Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 09/16] mm: Add unsafe_follow_pfn Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 10/16] media/videbuf1|2: Mark follow_pfn usage as unsafe Daniel Vetter
2020-10-21 8:56 ` Daniel Vetter [this message]
2020-10-21 8:56 ` [PATCH v3 12/16] PCI: Obey iomem restrictions for procfs mmap Daniel Vetter
2020-10-21 12:50 ` Jason Gunthorpe
2020-10-21 14:42 ` Daniel Vetter
2020-10-21 15:13 ` Jason Gunthorpe
2020-10-21 15:54 ` Daniel Vetter
2020-10-21 16:37 ` Jason Gunthorpe
2020-10-21 19:24 ` Daniel Vetter
2020-10-21 23:20 ` Jason Gunthorpe
2020-10-22 7:00 ` Daniel Vetter
2020-10-22 11:43 ` Jason Gunthorpe
2020-10-22 13:04 ` Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 13/16] /dev/mem: Only set filp->f_mapping Daniel Vetter
2020-10-21 18:21 ` Dan Williams
2020-10-21 8:56 ` [PATCH v3 14/16] resource: Move devmem revoke code to resource framework Daniel Vetter
2020-10-21 18:59 ` Dan Williams
2020-10-21 19:25 ` Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 15/16] sysfs: Support zapping of binary attr mmaps Daniel Vetter
2020-10-21 8:56 ` [PATCH v3 16/16] PCI: Revoke mappings like devmem Daniel Vetter
2020-10-21 12:51 ` [PATCH v3 00/16] follow_pfn and other iomap races Jason Gunthorpe
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