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, 29 insertions, 0 deletions

diff --git a/drivers/usb/dwc2/Makefile b/drivers/usb/dwc2/Makefile
new file mode 100644
index 000000000..2bcd6945d
--- /dev/null
+++ b/drivers/usb/dwc2/Makefile
@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0
+ccflags-$(CONFIG_USB_DWC2_DEBUG)	+= -DDEBUG
+ccflags-$(CONFIG_USB_DWC2_VERBOSE)	+= -DVERBOSE_DEBUG
+
+obj-$(CONFIG_USB_DWC2)			+= dwc2.o
+dwc2-y					:= core.o core_intr.o platform.o drd.o
+dwc2-y					+= params.o
+
+ifneq ($(filter y,$(CONFIG_USB_DWC2_HOST) $(CONFIG_USB_DWC2_DUAL_ROLE)),)
+	dwc2-y				+= hcd.o hcd_intr.o
+	dwc2-y				+= hcd_queue.o hcd_ddma.o
+endif
+
+ifneq ($(filter y,$(CONFIG_USB_DWC2_PERIPHERAL) $(CONFIG_USB_DWC2_DUAL_ROLE)),)
+	dwc2-y       			+= gadget.o
+endif
+
+ifneq ($(CONFIG_DEBUG_FS),)
+	dwc2-y				+= debugfs.o
+endif
+
+# NOTE: The previous s3c-hsotg peripheral mode only driver has been moved to
+# this location and renamed gadget.c. When building for dynamically linked
+# modules, dwc2.ko will get built for host mode, peripheral mode, and dual-role
+# mode. The PCI bus interface module will called dwc2_pci.ko and the platform
+# interface module will be called dwc2_platform.ko.
+
+obj-$(CONFIG_USB_DWC2_PCI)		+= dwc2_pci.o
+dwc2_pci-y				:= pci.o