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, 27 insertions, 0 deletions

diff --git a/drivers/usb/phy/phy-generic.h b/drivers/usb/phy/phy-generic.h
new file mode 100644
index 000000000..7ee80211a
--- /dev/null
+++ b/drivers/usb/phy/phy-generic.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _PHY_GENERIC_H_
+#define _PHY_GENERIC_H_
+
+#include <linux/usb/usb_phy_generic.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+
+struct usb_phy_generic {
+	struct usb_phy phy;
+	struct device *dev;
+	struct clk *clk;
+	struct regulator *vcc;
+	struct gpio_desc *gpiod_reset;
+	struct gpio_desc *gpiod_vbus;
+	struct regulator *vbus_draw;
+	bool vbus_draw_enabled;
+	unsigned long mA;
+	unsigned int vbus;
+};
+
+int usb_gen_phy_init(struct usb_phy *phy);
+void usb_gen_phy_shutdown(struct usb_phy *phy);
+
+int usb_phy_gen_create_phy(struct device *dev, struct usb_phy_generic *nop);
+
+#endif