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, 30 insertions, 0 deletions

diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
new file mode 100644
index 000000000..c6719694a
--- /dev/null
+++ b/drivers/clk/meson/Makefile
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Amlogic clock drivers
+
+obj-$(CONFIG_COMMON_CLK_MESON_CLKC_UTILS) += meson-clkc-utils.o
+obj-$(CONFIG_COMMON_CLK_MESON_AO_CLKC) += meson-aoclk.o
+obj-$(CONFIG_COMMON_CLK_MESON_CPU_DYNDIV) += clk-cpu-dyndiv.o
+obj-$(CONFIG_COMMON_CLK_MESON_DUALDIV) += clk-dualdiv.o
+obj-$(CONFIG_COMMON_CLK_MESON_MPLL) += clk-mpll.o
+obj-$(CONFIG_COMMON_CLK_MESON_PHASE) += clk-phase.o
+obj-$(CONFIG_COMMON_CLK_MESON_PLL) += clk-pll.o
+obj-$(CONFIG_COMMON_CLK_MESON_REGMAP) += clk-regmap.o
+obj-$(CONFIG_COMMON_CLK_MESON_SCLK_DIV) += sclk-div.o
+obj-$(CONFIG_COMMON_CLK_MESON_VID_PLL_DIV) += vid-pll-div.o
+obj-$(CONFIG_COMMON_CLK_MESON_VCLK) += vclk.o
+
+# Amlogic Clock controllers
+
+obj-$(CONFIG_COMMON_CLK_AXG) += axg.o axg-aoclk.o
+obj-$(CONFIG_COMMON_CLK_AXG_AUDIO) += axg-audio.o
+obj-$(CONFIG_COMMON_CLK_A1_PLL) += a1-pll.o
+obj-$(CONFIG_COMMON_CLK_A1_PERIPHERALS) += a1-peripherals.o
+obj-$(CONFIG_COMMON_CLK_C3_PLL) += c3-pll.o
+obj-$(CONFIG_COMMON_CLK_C3_PERIPHERALS) += c3-peripherals.o
+obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o
+obj-$(CONFIG_COMMON_CLK_G12A) += g12a.o g12a-aoclk.o
+obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o meson8-ddr.o
+obj-$(CONFIG_COMMON_CLK_S4_PLL) += s4-pll.o
+obj-$(CONFIG_COMMON_CLK_S4_PERIPHERALS) += s4-peripherals.o
+obj-$(CONFIG_COMMON_CLK_T7_PLL) += t7-pll.o
+obj-$(CONFIG_COMMON_CLK_T7_PERIPHERALS) += t7-peripherals.o