Messages in this thread | | | Date | Wed, 7 Oct 2020 13:46:34 -0500 | From | Bjorn Helgaas <> | Subject | Re: [PATCH 09/13] PCI: obey iomem restrictions for procfs mmap |
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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 >
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