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, 21 insertions, 0 deletions

diff --git a/drivers/pinctrl/bcm/Makefile b/drivers/pinctrl/bcm/Makefile
new file mode 100644
index 000000000..482d769b1
--- /dev/null
+++ b/drivers/pinctrl/bcm/Makefile
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: GPL-2.0
+# Broadcom pinctrl support
+
+obj-$(CONFIG_PINCTRL_BCM281XX)		+= pinctrl-bcm281xx.o
+obj-$(CONFIG_PINCTRL_BCM2835)		+= pinctrl-bcm2835.o
+obj-$(CONFIG_PINCTRL_BCM4908)		+= pinctrl-bcm4908.o
+obj-$(CONFIG_PINCTRL_BCM63XX)		+= pinctrl-bcm63xx.o
+obj-$(CONFIG_PINCTRL_BCM6318)		+= pinctrl-bcm6318.o
+obj-$(CONFIG_PINCTRL_BCM6328)		+= pinctrl-bcm6328.o
+obj-$(CONFIG_PINCTRL_BCM6358)		+= pinctrl-bcm6358.o
+obj-$(CONFIG_PINCTRL_BCM6362)		+= pinctrl-bcm6362.o
+obj-$(CONFIG_PINCTRL_BCM6368)		+= pinctrl-bcm6368.o
+obj-$(CONFIG_PINCTRL_BCM63268)		+= pinctrl-bcm63268.o
+obj-$(CONFIG_PINCTRL_BRCMSTB)		+= pinctrl-brcmstb.o
+obj-$(CONFIG_PINCTRL_BCM2712)		+= pinctrl-brcmstb-bcm2712.o
+obj-$(CONFIG_PINCTRL_IPROC_GPIO)	+= pinctrl-iproc-gpio.o
+obj-$(CONFIG_PINCTRL_CYGNUS_MUX)	+= pinctrl-cygnus-mux.o
+obj-$(CONFIG_PINCTRL_NS)		+= pinctrl-ns.o
+obj-$(CONFIG_PINCTRL_NSP_GPIO)		+= pinctrl-nsp-gpio.o
+obj-$(CONFIG_PINCTRL_NS2_MUX)		+= pinctrl-ns2-mux.o
+obj-$(CONFIG_PINCTRL_NSP_MUX)		+= pinctrl-nsp-mux.o