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, 18 insertions, 0 deletions

diff --git a/drivers/thunderbolt/Makefile b/drivers/thunderbolt/Makefile
new file mode 100644
index 000000000..beb054c31
--- /dev/null
+++ b/drivers/thunderbolt/Makefile
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-only
+ccflags-y := -I$(src)
+obj-${CONFIG_USB4} := thunderbolt.o
+thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o pci.o path.o tunnel.o eeprom.o
+thunderbolt-objs += domain.o dma_port.o icm.o property.o xdomain.o lc.o tmu.o usb4.o
+thunderbolt-objs += usb4_port.o nvm.o retimer.o quirks.o clx.o
+
+thunderbolt-${CONFIG_ACPI} += acpi.o
+thunderbolt-$(CONFIG_DEBUG_FS) += debugfs.o
+thunderbolt-$(CONFIG_USB4_CONFIGFS) += configfs.o
+thunderbolt-${CONFIG_USB4_KUNIT_TEST} += test.o
+CFLAGS_test.o += $(DISABLE_STRUCTLEAK_PLUGIN)
+
+thunderbolt_dma_test-${CONFIG_USB4_DMA_TEST} += dma_test.o
+obj-$(CONFIG_USB4_DMA_TEST) += thunderbolt_dma_test.o
+
+thunderbolt_stream-${CONFIG_USB4_STREAM} += stream.o
+obj-$(CONFIG_USB4_STREAM) += thunderbolt_stream.o