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, 32 insertions, 0 deletions

diff --git a/drivers/input/Makefile b/drivers/input/Makefile
new file mode 100644
index 000000000..2cd6e1c9a
--- /dev/null
+++ b/drivers/input/Makefile
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the input core drivers.
+#
+
+# Each configuration option enables a list of files.
+
+obj-$(CONFIG_INPUT)		+= input-core.o
+input-core-y := input.o input-compat.o input-mt.o input-poller.o ff-core.o
+input-core-y += touchscreen.o touch-overlay.o
+
+obj-$(CONFIG_INPUT_FF_MEMLESS)	+= ff-memless.o
+obj-$(CONFIG_INPUT_SPARSEKMAP)	+= sparse-keymap.o
+obj-$(CONFIG_INPUT_MATRIXKMAP)	+= matrix-keymap.o
+obj-$(CONFIG_INPUT_VIVALDIFMAP)	+= vivaldi-fmap.o
+
+obj-$(CONFIG_INPUT_LEDS)	+= input-leds.o
+obj-$(CONFIG_INPUT_MOUSEDEV)	+= mousedev.o
+obj-$(CONFIG_INPUT_JOYDEV)	+= joydev.o
+obj-$(CONFIG_INPUT_EVDEV)	+= evdev.o
+
+obj-$(CONFIG_INPUT_KEYBOARD)	+= keyboard/
+obj-$(CONFIG_INPUT_MOUSE)	+= mouse/
+obj-$(CONFIG_INPUT_JOYSTICK)	+= joystick/
+obj-$(CONFIG_INPUT_TABLET)	+= tablet/
+obj-$(CONFIG_INPUT_TOUCHSCREEN)	+= touchscreen/
+obj-$(CONFIG_INPUT_MISC)	+= misc/
+obj-$(CONFIG_INPUT_KUNIT_TEST)	+= tests/
+
+obj-$(CONFIG_INPUT_APMPOWER)	+= apm-power.o
+
+obj-$(CONFIG_RMI4_CORE)		+= rmi4/