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, 49 insertions, 0 deletions

diff --git a/drivers/pinctrl/starfive/Kconfig b/drivers/pinctrl/starfive/Kconfig
new file mode 100644
index 000000000..a9a7cb101
--- /dev/null
+++ b/drivers/pinctrl/starfive/Kconfig
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config PINCTRL_STARFIVE_JH7100
+	tristate "Pinctrl and GPIO driver for the StarFive JH7100 SoC"
+	depends on SOC_STARFIVE || COMPILE_TEST
+	depends on OF
+	select GENERIC_PINCTRL_GROUPS
+	select GENERIC_PINMUX_FUNCTIONS
+	select GENERIC_PINCONF
+	select GPIOLIB
+	select GPIOLIB_IRQCHIP
+	default SOC_STARFIVE
+	help
+	  Say yes here to support pin control on the StarFive JH7100 SoC.
+	  This also provides an interface to the GPIO pins not used by other
+	  peripherals supporting inputs, outputs, configuring pull-up/pull-down
+	  and interrupts on input changes.
+
+config PINCTRL_STARFIVE_JH7110
+	bool
+	select GENERIC_PINCTRL_GROUPS
+	select GENERIC_PINMUX_FUNCTIONS
+	select GENERIC_PINCONF
+	select GPIOLIB
+	select GPIOLIB_IRQCHIP
+
+config PINCTRL_STARFIVE_JH7110_SYS
+	tristate "System pinctrl and GPIO driver for the StarFive JH7110 SoC"
+	depends on SOC_STARFIVE  || COMPILE_TEST
+	depends on OF
+	select PINCTRL_STARFIVE_JH7110
+	default SOC_STARFIVE
+	help
+	  Say yes here to support system pin control on the StarFive JH7110 SoC.
+	  This also provides an interface to the GPIO pins not used by other
+	  peripherals supporting inputs, outputs, configuring pull-up/pull-down
+	  and interrupts on input changes.
+
+config PINCTRL_STARFIVE_JH7110_AON
+	tristate "Always-on pinctrl and GPIO driver for the StarFive JH7110 SoC"
+	depends on SOC_STARFIVE  || COMPILE_TEST
+	depends on OF
+	select PINCTRL_STARFIVE_JH7110
+	default SOC_STARFIVE
+	help
+	  Say yes here to support always-on pin control on the StarFive JH7110 SoC.
+	  This also provides an interface to the GPIO pins not used by other
+	  peripherals supporting inputs, outputs, configuring pull-up/pull-down
+	  and interrupts on input changes.