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, 90 insertions, 0 deletions

diff --git a/drivers/input/tablet/Kconfig b/drivers/input/tablet/Kconfig
new file mode 100644
index 000000000..ec27eff6a
--- /dev/null
+++ b/drivers/input/tablet/Kconfig
@@ -0,0 +1,90 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Tablet driver configuration
+#
+menuconfig INPUT_TABLET
+	bool "Tablets"
+	help
+	  Say Y here, and a list of supported tablets will be displayed.
+	  This option doesn't affect the kernel.
+
+	  If unsure, say Y.
+
+if INPUT_TABLET
+
+config TABLET_USB_ACECAD
+	tristate "Acecad Flair tablet support (USB)"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the USB version of the Acecad Flair
+	  tablet.  Make sure to say Y to "Mouse support"
+	  (CONFIG_INPUT_MOUSEDEV) and/or "Event interface support"
+	  (CONFIG_INPUT_EVDEV) as well.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called acecad.
+
+config TABLET_USB_AIPTEK
+	tristate "Aiptek 6000U/8000U and Genius G_PEN tablet support (USB)"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the USB version of the Aiptek 6000U,
+	  Aiptek 8000U or Genius G-PEN 560 tablet.  Make sure to say Y to
+	  "Mouse support" (CONFIG_INPUT_MOUSEDEV) and/or "Event interface
+	  support" (CONFIG_INPUT_EVDEV) as well.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called aiptek.
+
+config TABLET_USB_HANWANG
+	tristate "Hanwang Art Master III tablet support (USB)"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the USB version of the Hanwang Art
+	  Master III tablet.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hanwang.
+
+config TABLET_USB_KBTAB
+	tristate "KB Gear JamStudio tablet support (USB)"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the USB version of the KB Gear
+	  JamStudio tablet.  Make sure to say Y to "Mouse support"
+	  (CONFIG_INPUT_MOUSEDEV) and/or "Event interface support"
+	  (CONFIG_INPUT_EVDEV) as well.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called kbtab.
+
+config TABLET_USB_PEGASUS
+	tristate "Pegasus Mobile Notetaker Pen input tablet support"
+	depends on USB_ARCH_HAS_HCD
+	select USB
+	help
+	  Say Y here if you want to use the Pegasus Mobile Notetaker,
+	  also known as:
+	  Genie e-note The Notetaker,
+	  Staedtler Digital ballpoint pen 990 01,
+	  IRISnotes Express or
+	  NEWLink Digital Note Taker.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called pegasus_notetaker.
+
+config TABLET_SERIAL_WACOM4
+	tristate "Wacom protocol 4 serial tablet support"
+	select SERIO
+	help
+	  Say Y here if you want to use Wacom protocol 4 serial tablets.
+	  E.g. serial versions of the Cintiq, Graphire or Penpartner.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called wacom_serial4.
+
+endif