From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: DRI Development <dri-devel@lists.freedesktop.org>,
LKML <linux-kernel@vger.kernel.org>
Cc: linux-samsung-soc@vger.kernel.org, "Jan Kara" <jack@suse.cz>,
"Kees Cook" <keescook@chromium.org>,
kvm@vger.kernel.org, "Jason Gunthorpe" <jgg@ziepe.ca>,
"Daniel Vetter" <daniel.vetter@ffwll.ch>,
"Cornelia Huck" <cohuck@redhat.com>,
"Alex Williamson" <alex.williamson@redhat.com>,
linux-mm@kvack.org, "Jérôme Glisse" <jglisse@redhat.com>,
"John Hubbard" <jhubbard@nvidia.com>,
"Daniel Vetter" <daniel.vetter@intel.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org
Subject: [PATCH v5 10/15] vfio/type1: Mark follow_pfn as unsafe
Date: Fri, 30 Oct 2020 11:08:10 +0100 [thread overview]
Message-ID: <20201030100815.2269-11-daniel.vetter@ffwll.ch> (raw)
In-Reply-To: <20201030100815.2269-1-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.ch>
---
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 bb2684cc245e..eccfee900033 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
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next prev parent reply other threads:[~2020-10-30 10:09 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-30 10:08 [PATCH v5 00/15] follow_pfn and other iomap races Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 01/15] drm/exynos: Stop using frame_vector helpers Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 02/15] drm/exynos: Use FOLL_LONGTERM for g2d cmdlists Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 03/15] misc/habana: Stop using frame_vector helpers Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 04/15] misc/habana: Use FOLL_LONGTERM for userptr Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 05/15] mm/frame-vector: Use FOLL_LONGTERM Daniel Vetter
2020-10-30 14:11 ` Tomasz Figa
2020-10-30 14:37 ` Daniel Vetter
2020-11-02 18:19 ` Tomasz Figa
2020-10-31 2:55 ` John Hubbard
2020-10-31 14:45 ` Daniel Vetter
2020-11-01 5:22 ` John Hubbard
2020-11-01 10:30 ` Daniel Vetter
2020-11-01 21:13 ` John Hubbard
2020-11-01 22:50 ` Daniel Vetter
2020-11-04 14:00 ` Jason Gunthorpe
2020-11-04 15:54 ` Daniel Vetter
[not found] ` <20201104162125.GA13007@infradead.org>
2020-11-04 16:26 ` Daniel Vetter
[not found] ` <20201104163758.GA17425@infradead.org>
[not found] ` <20201104164119.GA18218@infradead.org>
2020-11-04 18:17 ` Jason Gunthorpe
2020-11-04 18:44 ` John Hubbard
2020-11-04 19:02 ` Jason Gunthorpe
2020-11-05 9:25 ` Daniel Vetter
2020-11-05 12:49 ` Jason Gunthorpe
2020-11-06 4:08 ` John Hubbard
2020-11-06 10:01 ` Daniel Vetter
2020-11-06 10:27 ` Daniel Vetter
2020-11-06 12:55 ` Jason Gunthorpe
2020-11-09 8:44 ` Thomas Hellström
2020-11-09 20:19 ` Jason Gunthorpe
2020-11-06 12:58 ` Jason Gunthorpe
2020-10-30 10:08 ` [PATCH v5 06/15] media: videobuf2: Move frame_vector into media subsystem Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 07/15] mm: Close race in generic_access_phys Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 08/15] mm: Add unsafe_follow_pfn Daniel Vetter
[not found] ` <20201102072931.GA16419@infradead.org>
2020-11-02 12:56 ` Daniel Vetter
2020-11-02 13:01 ` Jason Gunthorpe
2020-11-02 13:23 ` Daniel Vetter
2020-11-02 15:52 ` Jason Gunthorpe
2020-11-02 16:42 ` Daniel Vetter
2020-11-02 17:16 ` Jason Gunthorpe
2020-10-30 10:08 ` [PATCH v5 09/15] media/videbuf1|2: Mark follow_pfn usage as unsafe Daniel Vetter
2020-10-30 10:08 ` Daniel Vetter [this message]
2020-10-30 10:08 ` [PATCH v5 11/15] PCI: Obey iomem restrictions for procfs mmap Daniel Vetter
2020-11-03 21:28 ` Bjorn Helgaas
2020-11-03 22:09 ` Dan Williams
2020-11-04 8:44 ` Daniel Vetter
2020-11-04 16:50 ` Bjorn Helgaas
2020-11-04 20:12 ` Dan Williams
2020-11-05 9:34 ` Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 12/15] /dev/mem: Only set filp->f_mapping Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 13/15] resource: Move devmem revoke code to resource framework Daniel Vetter
2020-10-31 6:36 ` John Hubbard
2020-10-31 14:40 ` Daniel Vetter
2020-11-03 6:06 ` [resource] 22b17dc667: Kernel panic - not syncing: Fatal exception lkp
2020-11-03 6:15 ` John Hubbard
2020-11-03 10:10 ` Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 14/15] sysfs: Support zapping of binary attr mmaps Daniel Vetter
2020-10-30 10:08 ` [PATCH v5 15/15] PCI: Revoke mappings like devmem Daniel Vetter
2020-10-30 19:22 ` Dan Williams
2020-11-03 21:30 ` Bjorn Helgaas
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