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, 41 insertions, 0 deletions

diff --git a/drivers/pmdomain/qcom/Kconfig b/drivers/pmdomain/qcom/Kconfig
new file mode 100644
index 000000000..4abd43a88
--- /dev/null
+++ b/drivers/pmdomain/qcom/Kconfig
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "Qualcomm PM Domains"
+
+config QCOM_CPR
+	tristate "Qualcomm Core Power Reduction (CPR) support"
+	depends on (ARCH_QCOM || COMPILE_TEST) && HAS_IOMEM
+	select PM_OPP
+	select REGMAP
+	help
+	  Say Y here to enable support for the CPR hardware found on Qualcomm
+	  SoCs like QCS404.
+
+	  This driver populates CPU OPPs tables and makes adjustments to the
+	  tables based on feedback from the CPR hardware. If you want to do
+	  CPUfrequency scaling say Y here.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called qcom-cpr
+
+config QCOM_RPMHPD
+	tristate "Qualcomm RPMh Power domain driver"
+	depends on QCOM_RPMH && QCOM_COMMAND_DB
+	help
+	  QCOM RPMh Power domain driver to support power-domains with
+	  performance states. The driver communicates a performance state
+	  value to RPMh which then translates it into corresponding voltage
+	  for the voltage rail.
+
+config QCOM_RPMPD
+	tristate "Qualcomm RPM Power domain driver"
+	depends on PM && OF
+	depends on QCOM_SMD_RPM
+	select PM_GENERIC_DOMAINS
+	select PM_GENERIC_DOMAINS_OF
+	help
+	  QCOM RPM Power domain driver to support power-domains with
+	  performance states. The driver communicates a performance state
+	  value to RPM which then translates it into corresponding voltage
+	  for the voltage rail.
+
+endmenu