From: Daniel Vetter Date: Fri, 27 Nov 2020 16:41:22 +0000 (+0100) Subject: PCI: Obey iomem restrictions for procfs mmap X-Git-Tag: v5.12-rc1~73^2~5 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dc217d2c5a7efd3ba6c2da4be6f40038295e179c;p=thirdparty%2Flinux.git PCI: Obey iomem restrictions for procfs mmap 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 by adding the same iomem_is_exclusive() check we already have on the sysfs side in pci_mmap_resource(). Acked-by: Bjorn Helgaas References: 90a545e98126 ("restrict /dev/mem to idle io memory ranges") Signed-off-by: Daniel Vetter Cc: Jason Gunthorpe Cc: Kees Cook Cc: Dan Williams Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams 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 Cc: linux-pci@vger.kernel.org Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20201127164131.2244124-9-daniel.vetter@ffwll.ch --- diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index d35186b01d983..3a2f90beb4cb7 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)