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, 26 insertions, 0 deletions

diff --git a/drivers/clk/ti/Makefile b/drivers/clk/ti/Makefile
new file mode 100644
index 000000000..2c6315cfd
--- /dev/null
+++ b/drivers/clk/ti/Makefile
@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: GPL-2.0
+ifeq ($(CONFIG_ARCH_OMAP2PLUS), y)
+
+obj-y					+= clk.o autoidle.o clockdomain.o
+clk-common				= dpll.o composite.o divider.o gate.o \
+					  fixed-factor.o mux.o apll.o \
+					  clkt_dpll.o clkt_iclk.o clkt_dflt.o \
+					  clkctrl.o
+obj-$(CONFIG_SOC_AM33XX)		+= $(clk-common) clk-33xx.o dpll3xxx.o
+obj-$(CONFIG_SOC_TI81XX)		+= $(clk-common) fapll.o clk-814x.o clk-816x.o
+obj-$(CONFIG_ARCH_OMAP2)		+= $(clk-common) interface.o clk-2xxx.o
+obj-$(CONFIG_ARCH_OMAP3)		+= $(clk-common) interface.o \
+					   clk-3xxx.o dpll3xxx.o
+obj-$(CONFIG_ARCH_OMAP4)		+= $(clk-common) clk-44xx.o \
+					   dpll3xxx.o dpll44xx.o
+obj-$(CONFIG_SOC_OMAP5)			+= $(clk-common) clk-54xx.o \
+					   dpll3xxx.o dpll44xx.o
+obj-$(CONFIG_SOC_DRA7XX)		+= $(clk-common) clk-7xx.o \
+					   clk-dra7-atl.o dpll3xxx.o \
+					   dpll44xx.o
+
+obj-$(CONFIG_SOC_AM43XX)		+= $(clk-common) dpll3xxx.o clk-43xx.o
+
+endif	# CONFIG_ARCH_OMAP2PLUS
+
+obj-$(CONFIG_COMMON_CLK_TI_ADPLL)	+= adpll.o