openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted

sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user
pointers, v1 and v2, and swaps the words they point to in hand-written
assembly.

    l.lwz   r29,0(r4)
    l.lwz   r27,0(r5)
    l.sw    0(r4),r27
    l.sw    0(r5),r29

The pointers are not checked with access_ok(). The four memory
accesses also have no exception table entries.

A caller passes a kernel address as either pointer, and the syscall
reads from and writes to it directly.

This gives an unprivileged process a kernel read/write primitive. It
overwrites kernel data such as the sys_call_table, gaining code
execution in kernel context.

Check both pointers before entering the critical section. Add fixups
for the four memory accesses so faults on valid but unmapped user
addresses return -EFAULT.

[shorne@gmail.com: fix comment style]
Fixes: 9d02a4283e9c ("OpenRISC: Boot code")
Cc: stable@vger.kernel.org
Signed-off-by: Ali Ahmet Memis <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/usb/roles/Kconfig b/drivers/usb/roles/Kconfig
new file mode 100644
index 000000000..f8b31aa67
--- /dev/null
+++ b/drivers/usb/roles/Kconfig
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config USB_ROLE_SWITCH
+	tristate "USB Role Switch Support"
+	help
+	  USB Role Switch is a device that can select the USB role - host or
+	  device - for a USB port (connector). In most cases dual-role capable
+	  USB controller will also represent the switch, but on some platforms
+	  multiplexer/demultiplexer switch is used to route the data lines on
+	  the USB connector between separate USB host and device controllers.
+
+	  Say Y here if your USB connectors support both device and host roles.
+	  To compile the driver as module, choose M here: the module will be
+	  called roles.ko.
+
+if USB_ROLE_SWITCH
+
+config USB_ROLES_INTEL_XHCI
+	tristate "Intel XHCI USB Role Switch"
+	depends on ACPI && X86
+	help
+	  Driver for the internal USB role switch for switching the USB data
+	  lines between the xHCI host controller and the dwc3 gadget controller
+	  found on various Intel SoCs.
+
+	  To compile the driver as a module, choose M here: the module will
+	  be called intel-xhci-usb-role-switch.
+
+endif # USB_ROLE_SWITCH