| Message ID | 149142337836.5101.13971561682218232219.stgit@warthog.procyon.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Wed, Apr 05, 2017 at 09:16:18PM +0100, David Howells wrote: > From: Matthew Garrett <matthew.garrett@nebula.com> > > Any hardware that can potentially generate DMA has to be locked down in > order to avoid it being possible for an attacker to modify kernel code, > allowing them to circumvent disabled module loading or module signing. > Default to paranoid - in future we can potentially relax this for > sufficiently IOMMU-isolated devices. > > Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com> > Signed-off-by: David Howells <dhowells@redhat.com> > cc: linux-pci@vger.kernel.org Acked-by: Bjorn Helgaas <bhelgaas@google.com> > --- > > drivers/pci/pci-sysfs.c | 9 +++++++++ > drivers/pci/proc.c | 8 +++++++- > drivers/pci/syscall.c | 2 +- > 3 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index 25d010d449a3..f70b3668036f 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -727,6 +727,9 @@ static ssize_t pci_write_config(struct file *filp, struct kobject *kobj, > loff_t init_off = off; > u8 *data = (u8 *) buf; > > + if (kernel_is_locked_down()) > + return -EPERM; > + > if (off > dev->cfg_size) > return 0; > if (off + count > dev->cfg_size) { > @@ -1018,6 +1021,9 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr, > resource_size_t start, end; > int i; > > + if (kernel_is_locked_down()) > + return -EPERM; > + > for (i = 0; i < PCI_ROM_RESOURCE; i++) > if (res == &pdev->resource[i]) > break; > @@ -1117,6 +1123,9 @@ static ssize_t pci_write_resource_io(struct file *filp, struct kobject *kobj, > struct bin_attribute *attr, char *buf, > loff_t off, size_t count) > { > + if (kernel_is_locked_down()) > + return -EPERM; > + > return pci_resource_io(filp, kobj, attr, buf, off, count, true); > } > > diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c > index f82710a8694d..139d6f09ae7b 100644 > --- a/drivers/pci/proc.c > +++ b/drivers/pci/proc.c > @@ -116,6 +116,9 @@ static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf, > int size = dev->cfg_size; > int cnt; > > + if (kernel_is_locked_down()) > + return -EPERM; > + > if (pos >= size) > return 0; > if (nbytes >= size) > @@ -195,6 +198,9 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd, > #endif /* HAVE_PCI_MMAP */ > int ret = 0; > > + if (kernel_is_locked_down()) > + return -EPERM; > + > switch (cmd) { > case PCIIOC_CONTROLLER: > ret = pci_domain_nr(dev->bus); > @@ -233,7 +239,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) > struct pci_filp_private *fpriv = file->private_data; > int i, ret, write_combine; > > - if (!capable(CAP_SYS_RAWIO)) > + if (!capable(CAP_SYS_RAWIO) || kernel_is_locked_down()) > return -EPERM; > > /* Make sure the caller is mapping a real resource for this device */ > diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c > index 9bf993e1f71e..c09524738ceb 100644 > --- a/drivers/pci/syscall.c > +++ b/drivers/pci/syscall.c > @@ -92,7 +92,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn, > u32 dword; > int err = 0; > > - if (!capable(CAP_SYS_ADMIN)) > + if (!capable(CAP_SYS_ADMIN) || kernel_is_locked_down()) > return -EPERM; > > dev = pci_get_bus_and_slot(bus, dfn); >
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 25d010d449a3..f70b3668036f 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -727,6 +727,9 @@ static ssize_t pci_write_config(struct file *filp, struct kobject *kobj, loff_t init_off = off; u8 *data = (u8 *) buf; + if (kernel_is_locked_down()) + return -EPERM; + if (off > dev->cfg_size) return 0; if (off + count > dev->cfg_size) { @@ -1018,6 +1021,9 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr, resource_size_t start, end; int i; + if (kernel_is_locked_down()) + return -EPERM; + for (i = 0; i < PCI_ROM_RESOURCE; i++) if (res == &pdev->resource[i]) break; @@ -1117,6 +1123,9 @@ static ssize_t pci_write_resource_io(struct file *filp, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { + if (kernel_is_locked_down()) + return -EPERM; + return pci_resource_io(filp, kobj, attr, buf, off, count, true); } diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index f82710a8694d..139d6f09ae7b 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -116,6 +116,9 @@ static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf, int size = dev->cfg_size; int cnt; + if (kernel_is_locked_down()) + return -EPERM; + if (pos >= size) return 0; if (nbytes >= size) @@ -195,6 +198,9 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd, #endif /* HAVE_PCI_MMAP */ int ret = 0; + if (kernel_is_locked_down()) + return -EPERM; + switch (cmd) { case PCIIOC_CONTROLLER: ret = pci_domain_nr(dev->bus); @@ -233,7 +239,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) struct pci_filp_private *fpriv = file->private_data; int i, ret, write_combine; - if (!capable(CAP_SYS_RAWIO)) + if (!capable(CAP_SYS_RAWIO) || kernel_is_locked_down()) return -EPERM; /* Make sure the caller is mapping a real resource for this device */ diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c index 9bf993e1f71e..c09524738ceb 100644 --- a/drivers/pci/syscall.c +++ b/drivers/pci/syscall.c @@ -92,7 +92,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn, u32 dword; int err = 0; - if (!capable(CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN) || kernel_is_locked_down()) return -EPERM; dev = pci_get_bus_and_slot(bus, dfn);