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, 33 insertions, 0 deletions

diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
new file mode 100644
index 000000000..7f5137dc0
--- /dev/null
+++ b/drivers/input/serio/Makefile
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the input core drivers.
+#
+
+# Each configuration option enables a list of files.
+
+obj-$(CONFIG_SERIO)		+= serio.o
+obj-$(CONFIG_SERIO_I8042)	+= i8042.o
+obj-$(CONFIG_SERIO_PARKBD)	+= parkbd.o
+obj-$(CONFIG_SERIO_SERPORT)	+= serport.o
+obj-$(CONFIG_SERIO_RPCKBD)	+= rpckbd.o
+obj-$(CONFIG_SERIO_SA1111)	+= sa1111ps2.o
+obj-$(CONFIG_SERIO_AMBAKMI)	+= ambakmi.o
+obj-$(CONFIG_SERIO_Q40KBD)	+= q40kbd.o
+obj-$(CONFIG_SERIO_GSCPS2)	+= gscps2.o
+obj-$(CONFIG_HP_SDC)		+= hp_sdc.o
+obj-$(CONFIG_HIL_MLC)		+= hp_sdc_mlc.o hil_mlc.o
+obj-$(CONFIG_SERIO_PCIPS2)	+= pcips2.o
+obj-$(CONFIG_SERIO_PS2MULT)	+= ps2mult.o
+obj-$(CONFIG_SERIO_MACEPS2)	+= maceps2.o
+obj-$(CONFIG_SERIO_SGI_IOC3)	+= ioc3kbd.o
+obj-$(CONFIG_SERIO_LIBPS2)	+= libps2.o
+obj-$(CONFIG_SERIO_RAW)		+= serio_raw.o
+obj-$(CONFIG_SERIO_AMS_DELTA)	+= ams_delta_serio.o
+obj-$(CONFIG_SERIO_ALTERA_PS2)	+= altera_ps2.o
+obj-$(CONFIG_SERIO_ARC_PS2)	+= arc_ps2.o
+obj-$(CONFIG_SERIO_APBPS2)	+= apbps2.o
+obj-$(CONFIG_SERIO_OLPC_APSP)	+= olpc_apsp.o
+obj-$(CONFIG_HYPERV_KEYBOARD)	+= hyperv-keyboard.o
+obj-$(CONFIG_SERIO_SUN4I_PS2)	+= sun4i-ps2.o
+obj-$(CONFIG_SERIO_GPIO_PS2)	+= ps2-gpio.o
+obj-$(CONFIG_USERIO)		+= userio.o