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