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, 39 insertions, 0 deletions

diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
new file mode 100644
index 000000000..4010d17f8
--- /dev/null
+++ b/drivers/net/can/Makefile
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+#  Makefile for the Linux Controller Area Network drivers.
+#
+
+obj-$(CONFIG_CAN_VCAN)		+= vcan.o
+obj-$(CONFIG_CAN_VXCAN)		+= vxcan.o
+obj-$(CONFIG_CAN_SLCAN)		+= slcan/
+
+obj-y				+= dev/
+obj-y				+= esd/
+obj-y				+= rcar/
+obj-y				+= rockchip/
+obj-y				+= spi/
+obj-y				+= usb/
+obj-y				+= softing/
+
+obj-$(CONFIG_CAN_AT91)		+= at91_can.o
+obj-$(CONFIG_CAN_BXCAN)		+= bxcan.o
+obj-$(CONFIG_CAN_CAN327)	+= can327.o
+obj-$(CONFIG_CAN_CC770)		+= cc770/
+obj-$(CONFIG_CAN_C_CAN)		+= c_can/
+obj-$(CONFIG_CAN_CTUCANFD)	+= ctucanfd/
+obj-$(CONFIG_CAN_DUMMY)		+= dummy_can.o
+obj-$(CONFIG_CAN_FLEXCAN)	+= flexcan/
+obj-$(CONFIG_CAN_GRCAN)		+= grcan.o
+obj-$(CONFIG_CAN_IFI_CANFD)	+= ifi_canfd/
+obj-$(CONFIG_CAN_JANZ_ICAN3)	+= janz-ican3.o
+obj-$(CONFIG_CAN_KVASER_PCIEFD)	+= kvaser_pciefd/
+obj-$(CONFIG_CAN_MSCAN)		+= mscan/
+obj-$(CONFIG_CAN_M_CAN)		+= m_can/
+obj-$(CONFIG_CAN_PEAK_PCIEFD)	+= peak_canfd/
+obj-$(CONFIG_CAN_SJA1000)	+= sja1000/
+obj-$(CONFIG_CAN_SUN4I)		+= sun4i_can.o
+obj-$(CONFIG_CAN_TI_HECC)	+= ti_hecc.o
+obj-$(CONFIG_CAN_VIRTIO_CAN)	+= virtio_can.o
+obj-$(CONFIG_CAN_XILINXCAN)	+= xilinx_can.o
+
+subdir-ccflags-$(CONFIG_CAN_DEBUG_DEVICES) += -DDEBUG