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-rw-r--r--PCI-Lock-down-BAR-access-when-module-security-is-ena.patch117
1 files changed, 117 insertions, 0 deletions
diff --git a/PCI-Lock-down-BAR-access-when-module-security-is-ena.patch b/PCI-Lock-down-BAR-access-when-module-security-is-ena.patch
new file mode 100644
index 000000000..4bc2c9178
--- /dev/null
+++ b/PCI-Lock-down-BAR-access-when-module-security-is-ena.patch
@@ -0,0 +1,117 @@
+From ba3b2c51e65b95125e4c29725d6c7180d4dea061 Mon Sep 17 00:00:00 2001
+From: Matthew Garrett <matthew.garrett@nebula.com>
+Date: Thu, 8 Mar 2012 10:10:38 -0500
+Subject: [PATCH] PCI: Lock down BAR access when module security is enabled
+
+Any hardware that can potentially generate DMA has to be locked down from
+userspace 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>
+---
+ drivers/pci/pci-sysfs.c | 10 ++++++++++
+ drivers/pci/proc.c | 8 +++++++-
+ drivers/pci/syscall.c | 3 ++-
+ 3 files changed, 19 insertions(+), 2 deletions(-)
+
+diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
+index 9ff0a901ecf7..8d0d5d92b8d9 100644
+--- a/drivers/pci/pci-sysfs.c
++++ b/drivers/pci/pci-sysfs.c
+@@ -30,6 +30,7 @@
+ #include <linux/vgaarb.h>
+ #include <linux/pm_runtime.h>
+ #include <linux/of.h>
++#include <linux/module.h>
+ #include "pci.h"
+
+ static int sysfs_initialized; /* = 0 */
+@@ -704,6 +705,9 @@ static ssize_t pci_write_config(struct file *filp, struct kobject *kobj,
+ loff_t init_off = off;
+ u8 *data = (u8 *) buf;
+
++ if (secure_modules())
++ return -EPERM;
++
+ if (off > dev->cfg_size)
+ return 0;
+ if (off + count > dev->cfg_size) {
+@@ -998,6 +1002,9 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
+ resource_size_t start, end;
+ int i;
+
++ if (secure_modules())
++ return -EPERM;
++
+ for (i = 0; i < PCI_ROM_RESOURCE; i++)
+ if (res == &pdev->resource[i])
+ break;
+@@ -1099,6 +1106,9 @@ 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 (secure_modules())
++ 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 3f155e78513f..4265ea07e3b0 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 (secure_modules())
++ 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 (secure_modules())
++ 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;
+
+- if (!capable(CAP_SYS_RAWIO))
++ if (!capable(CAP_SYS_RAWIO) || secure_modules())
+ 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 b91c4da68365..98f5637304d1 100644
+--- a/drivers/pci/syscall.c
++++ b/drivers/pci/syscall.c
+@@ -10,6 +10,7 @@
+ #include <linux/errno.h>
+ #include <linux/pci.h>
+ #include <linux/syscalls.h>
++#include <linux/module.h>
+ #include <asm/uaccess.h>
+ #include "pci.h"
+
+@@ -92,7 +93,7 @@ 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) || secure_modules())
+ return -EPERM;
+
+ dev = pci_get_bus_and_slot(bus, dfn);
+--
+1.9.3
+