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, 32 insertions, 0 deletions

diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile
new file mode 100644
index 000000000..a0715cdfc
--- /dev/null
+++ b/drivers/clk/tegra/Makefile
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y					+= clk.o
+obj-y					+= clk-audio-sync.o
+obj-y					+= clk-device.o
+obj-y					+= clk-dfll.o
+obj-y					+= clk-divider.o
+obj-y					+= clk-periph.o
+obj-y					+= clk-periph-fixed.o
+obj-y					+= clk-periph-gate.o
+obj-y					+= clk-pll.o
+obj-y					+= clk-pll-out.o
+obj-y					+= clk-sdmmc-mux.o
+obj-y					+= clk-super.o
+obj-y					+= clk-tegra-audio.o
+obj-y					+= clk-tegra-periph.o
+obj-y					+= clk-tegra-fixed.o
+obj-y					+= clk-tegra-super-cclk.o
+obj-y					+= clk-tegra-super-gen4.o
+obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += clk-tegra20.o
+obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= clk-tegra20-emc.o
+obj-$(CONFIG_ARCH_TEGRA_3x_SOC)         += clk-tegra30.o
+obj-$(CONFIG_ARCH_TEGRA_3x_SOC)		+= clk-tegra20-emc.o
+obj-$(CONFIG_ARCH_TEGRA_114_SOC)	+= clk-tegra114.o
+obj-$(CONFIG_ARCH_TEGRA_124_SOC)	+= clk-tegra124.o
+obj-$(CONFIG_TEGRA_CLK_DFLL)		+= clk-tegra124-dfll-fcpu.o
+obj-$(CONFIG_TEGRA124_CLK_EMC)		+= clk-tegra124-emc.o
+obj-$(CONFIG_ARCH_TEGRA_132_SOC)	+= clk-tegra124.o
+obj-y					+= cvb.o
+obj-$(CONFIG_ARCH_TEGRA_210_SOC)	+= clk-tegra210.o
+obj-$(CONFIG_ARCH_TEGRA_210_SOC)	+= clk-tegra210-emc.o
+obj-$(CONFIG_CLK_TEGRA_BPMP)		+= clk-bpmp.o
+obj-y					+= clk-utils.o