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, 19 insertions, 0 deletions

diff --git a/drivers/usb/chipidea/Makefile b/drivers/usb/chipidea/Makefile
new file mode 100644
index 000000000..718cb2460
--- /dev/null
+++ b/drivers/usb/chipidea/Makefile
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# define_trace.h needs to know how to find our header
+CFLAGS_trace.o			:= -I$(src)
+obj-$(CONFIG_USB_CHIPIDEA)		+= ci_hdrc.o
+
+ci_hdrc-y				:= core.o otg.o debug.o ulpi.o
+ci_hdrc-$(CONFIG_USB_CHIPIDEA_UDC)	+= udc.o trace.o
+ci_hdrc-$(CONFIG_USB_CHIPIDEA_HOST)	+= host.o
+ci_hdrc-$(CONFIG_USB_OTG_FSM)		+= otg_fsm.o
+
+# Glue/Bridge layers go here
+
+obj-$(CONFIG_USB_CHIPIDEA_GENERIC)	+= ci_hdrc_usb2.o
+obj-$(CONFIG_USB_CHIPIDEA_MSM)		+= ci_hdrc_msm.o
+obj-$(CONFIG_USB_CHIPIDEA_NPCM)		+= ci_hdrc_npcm.o
+obj-$(CONFIG_USB_CHIPIDEA_PCI)		+= ci_hdrc_pci.o
+obj-$(CONFIG_USB_CHIPIDEA_IMX)		+= usbmisc_imx.o ci_hdrc_imx.o
+obj-$(CONFIG_USB_CHIPIDEA_TEGRA)	+= ci_hdrc_tegra.o