| Message ID | 20201007164426.1812530-10-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | follow_pfn and other iomap races | expand |
On Wed, Oct 07, 2020 at 06:44:22PM +0200, Daniel Vetter wrote: > There's three ways to access pci bars from userspace: /dev/mem, sysfs > files, and the old proc interface. Two check against > iomem_is_exclusive, proc never did. And with CONFIG_IO_STRICT_DEVMEM, > this starts to matter, since we don't want random userspace having > access to pci bars while a driver is loaded and using it. > > Fix this. Please mention *how* you're fixing this. I know you can sort of deduce it from the first paragraph, but it's easy to save readers the trouble. s/pci/PCI/ s/bars/BARs/ Capitalize subject to match other patches. > References: 90a545e98126 ("restrict /dev/mem to idle io memory ranges") > 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: Bjorn Helgaas <bhelgaas@google.com> > Cc: linux-pci@vger.kernel.org > --- > drivers/pci/proc.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c > index d35186b01d98..3a2f90beb4cb 100644 > --- a/drivers/pci/proc.c > +++ b/drivers/pci/proc.c > @@ -274,6 +274,11 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) > else > return -EINVAL; > } > + > + if (dev->resource[i].flags & IORESOURCE_MEM && > + iomem_is_exclusive(dev->resource[i].start)) > + return -EINVAL; > + > ret = pci_mmap_page_range(dev, i, vma, > fpriv->mmap_state, write_combine); > if (ret < 0) > -- > 2.28.0 >
diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index d35186b01d98..3a2f90beb4cb 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -274,6 +274,11 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) else return -EINVAL; } + + if (dev->resource[i].flags & IORESOURCE_MEM && + iomem_is_exclusive(dev->resource[i].start)) + return -EINVAL; + ret = pci_mmap_page_range(dev, i, vma, fpriv->mmap_state, write_combine); if (ret < 0)
There's three ways to access pci bars from userspace: /dev/mem, sysfs files, and the old proc interface. Two check against iomem_is_exclusive, proc never did. And with CONFIG_IO_STRICT_DEVMEM, this starts to matter, since we don't want random userspace having access to pci bars while a driver is loaded and using it. Fix this. References: 90a545e98126 ("restrict /dev/mem to idle io memory ranges") 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: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-pci@vger.kernel.org --- drivers/pci/proc.c | 5 +++++ 1 file changed, 5 insertions(+)