This is a note to let you know that I've just added the patch titled PCI: Only allow WC mmap on prefetchable resources to the 4.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pci-only-allow-wc-mmap-on-prefetchable-resources.patch and it can be found in the queue-4.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From cef4d02305a06be581bb7f4353446717a1b319ec Mon Sep 17 00:00:00 2001 From: David Woodhouse <dwmw@xxxxxxxxxxxx> Date: Wed, 12 Apr 2017 13:25:52 +0100 Subject: PCI: Only allow WC mmap on prefetchable resources From: David Woodhouse <dwmw@xxxxxxxxxxxx> commit cef4d02305a06be581bb7f4353446717a1b319ec upstream. The /proc/bus/pci mmap interface allows the user to specify whether they want WC or not. Don't let them do so on non-prefetchable BARs. Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pci/proc.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -231,7 +231,7 @@ static int proc_bus_pci_mmap(struct file { struct pci_dev *dev = PDE_DATA(file_inode(file)); struct pci_filp_private *fpriv = file->private_data; - int i, ret, write_combine, res_bit; + int i, ret, write_combine = 0, res_bit; if (!capable(CAP_SYS_RAWIO)) return -EPERM; @@ -251,10 +251,13 @@ static int proc_bus_pci_mmap(struct file if (i >= PCI_ROM_RESOURCE) return -ENODEV; - if (fpriv->mmap_state == pci_mmap_mem) - write_combine = fpriv->write_combine; - else - write_combine = 0; + if (fpriv->mmap_state == pci_mmap_mem && + fpriv->write_combine) { + if (dev->resource[i].flags & IORESOURCE_PREFETCH) + write_combine = 1; + else + return -EINVAL; + } ret = pci_mmap_page_range(dev, vma, fpriv->mmap_state, write_combine); if (ret < 0) Patches currently in stable-queue which might be from dwmw@xxxxxxxxxxxx are queue-4.11/pci-fix-another-sanity-check-bug-in-proc-pci-mmap.patch queue-4.11/pci-only-allow-wc-mmap-on-prefetchable-resources.patch queue-4.11/pci-fix-pci_mmap_fits-for-have_pci_resource_to_user-platforms.patch queue-4.11/iommu-vt-d-flush-the-iotlb-to-get-rid-of-the-initial-kdump-mappings.patch