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, 48 insertions, 0 deletions

diff --git a/drivers/phy/starfive/Kconfig b/drivers/phy/starfive/Kconfig
new file mode 100644
index 000000000..d0cdd7cb4
--- /dev/null
+++ b/drivers/phy/starfive/Kconfig
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for StarFive platforms
+#
+
+if ARCH_STARFIVE || COMPILE_TEST
+
+config PHY_STARFIVE_JH7110_DPHY_RX
+	tristate "StarFive JH7110 D-PHY RX support"
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Choose this option if you have a StarFive D-PHY in your
+	  system. If M is selected, the module will be called
+	  phy-jh7110-dphy-rx.ko.
+
+config PHY_STARFIVE_JH7110_DPHY_TX
+	tristate "StarFive JH7110 D-PHY TX Support"
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Choose this option if you have a StarFive D-PHY TX in your
+	  system. If M is selected, the module will be called
+	  phy-jh7110-dphy-tx.ko.
+
+config PHY_STARFIVE_JH7110_PCIE
+	tristate "Starfive JH7110 PCIE 2.0/USB 3.0 PHY support"
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support the StarFive PCIe 2.0 PHY,
+	  or used as USB 3.0 PHY.
+	  If M is selected, the module will be called
+	  phy-jh7110-pcie.ko.
+
+config PHY_STARFIVE_JH7110_USB
+	tristate "Starfive JH7110 USB 2.0 PHY support"
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	help
+	  Enable this to support the StarFive USB 2.0 PHY,
+	  used with the Cadence USB controller.
+	  If M is selected, the module will be called
+	  phy-jh7110-usb.ko.
+
+endif # ARCH_STARFIVE || COMPILE_TEST