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, 200 insertions, 0 deletions

diff --git a/drivers/net/phy/rockchip.c b/drivers/net/phy/rockchip.c
new file mode 100644
index 000000000..b338f385e
--- /dev/null
+++ b/drivers/net/phy/rockchip.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * drivers/net/phy/rockchip.c
+ *
+ * Driver for ROCKCHIP Ethernet PHYs
+ *
+ * Copyright (c) 2017, Fuzhou Rockchip Electronics Co., Ltd
+ *
+ * David Wu <david.wu@rock-chips.com>
+ */
+
+#include <linux/ethtool.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/netdevice.h>
+#include <linux/phy.h>
+
+#define INTERNAL_EPHY_ID			0x1234d400
+
+#define MII_INTERNAL_CTRL_STATUS		17
+#define SMI_ADDR_TSTCNTL			20
+#define SMI_ADDR_TSTREAD1			21
+#define SMI_ADDR_TSTREAD2			22
+#define SMI_ADDR_TSTWRITE			23
+#define MII_SPECIAL_CONTROL_STATUS		31
+
+#define MII_AUTO_MDIX_EN			BIT(7)
+#define MII_MDIX_EN				BIT(6)
+
+#define MII_SPEED_10				BIT(2)
+#define MII_SPEED_100				BIT(3)
+
+#define TSTCNTL_RD				(BIT(15) | BIT(10))
+#define TSTCNTL_WR				(BIT(14) | BIT(10))
+
+#define TSTMODE_ENABLE				0x400
+#define TSTMODE_DISABLE				0x0
+
+#define WR_ADDR_A7CFG				0x18
+
+static int rockchip_init_tstmode(struct phy_device *phydev)
+{
+	int ret;
+
+	/* Enable access to Analog and DSP register banks */
+	ret = phy_write(phydev, SMI_ADDR_TSTCNTL, TSTMODE_ENABLE);
+	if (ret)
+		return ret;
+
+	ret = phy_write(phydev, SMI_ADDR_TSTCNTL, TSTMODE_DISABLE);
+	if (ret)
+		return ret;
+
+	return phy_write(phydev, SMI_ADDR_TSTCNTL, TSTMODE_ENABLE);
+}
+
+static int rockchip_close_tstmode(struct phy_device *phydev)
+{
+	/* Back to basic register bank */
+	return phy_write(phydev, SMI_ADDR_TSTCNTL, TSTMODE_DISABLE);
+}
+
+static int rockchip_integrated_phy_analog_init(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = rockchip_init_tstmode(phydev);
+	if (ret)
+		return ret;
+
+	/*
+	 * Adjust tx amplitude to make sginal better,
+	 * the default value is 0x8.
+	 */
+	ret = phy_write(phydev, SMI_ADDR_TSTWRITE, 0xB);
+	if (ret)
+		return ret;
+	ret = phy_write(phydev, SMI_ADDR_TSTCNTL, TSTCNTL_WR | WR_ADDR_A7CFG);
+	if (ret)
+		return ret;
+
+	return rockchip_close_tstmode(phydev);
+}
+
+static int rockchip_integrated_phy_config_init(struct phy_device *phydev)
+{
+	int val, ret;
+
+	/*
+	 * The auto MIDX has linked problem on some board,
+	 * workround to disable auto MDIX.
+	 */
+	val = phy_read(phydev, MII_INTERNAL_CTRL_STATUS);
+	if (val < 0)
+		return val;
+	val &= ~MII_AUTO_MDIX_EN;
+	ret = phy_write(phydev, MII_INTERNAL_CTRL_STATUS, val);
+	if (ret)
+		return ret;
+
+	return rockchip_integrated_phy_analog_init(phydev);
+}
+
+static void rockchip_link_change_notify(struct phy_device *phydev)
+{
+	/*
+	 * If mode switch happens from 10BT to 100BT, all DSP/AFE
+	 * registers are set to default values. So any AFE/DSP
+	 * registers have to be re-initialized in this case.
+	 */
+	if (phydev->state == PHY_RUNNING && phydev->speed == SPEED_100) {
+		int ret = rockchip_integrated_phy_analog_init(phydev);
+
+		if (ret)
+			phydev_err(phydev, "rockchip_integrated_phy_analog_init err: %d.\n",
+				   ret);
+	}
+}
+
+static int rockchip_set_polarity(struct phy_device *phydev, int polarity)
+{
+	int reg, err, val;
+
+	/* get the current settings */
+	reg = phy_read(phydev, MII_INTERNAL_CTRL_STATUS);
+	if (reg < 0)
+		return reg;
+
+	reg &= ~MII_AUTO_MDIX_EN;
+	val = reg;
+	switch (polarity) {
+	case ETH_TP_MDI:
+		val &= ~MII_MDIX_EN;
+		break;
+	case ETH_TP_MDI_X:
+		val |= MII_MDIX_EN;
+		break;
+	case ETH_TP_MDI_AUTO:
+	case ETH_TP_MDI_INVALID:
+	default:
+		return 0;
+	}
+
+	if (val != reg) {
+		/* Set the new polarity value in the register */
+		err = phy_write(phydev, MII_INTERNAL_CTRL_STATUS, val);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+static int rockchip_config_aneg(struct phy_device *phydev)
+{
+	int err;
+
+	err = rockchip_set_polarity(phydev, phydev->mdix);
+	if (err < 0)
+		return err;
+
+	return genphy_config_aneg(phydev);
+}
+
+static int rockchip_phy_resume(struct phy_device *phydev)
+{
+	genphy_resume(phydev);
+
+	return rockchip_integrated_phy_config_init(phydev);
+}
+
+static struct phy_driver rockchip_phy_driver[] = {
+{
+	.phy_id			= INTERNAL_EPHY_ID,
+	.phy_id_mask		= 0xfffffff0,
+	.name			= "Rockchip integrated EPHY",
+	/* PHY_BASIC_FEATURES */
+	.flags			= 0,
+	.link_change_notify	= rockchip_link_change_notify,
+	.soft_reset		= genphy_soft_reset,
+	.config_init		= rockchip_integrated_phy_config_init,
+	.config_aneg		= rockchip_config_aneg,
+	.suspend		= genphy_suspend,
+	.resume			= rockchip_phy_resume,
+},
+};
+
+module_phy_driver(rockchip_phy_driver);
+
+static const struct mdio_device_id __maybe_unused rockchip_phy_tbl[] = {
+	{ INTERNAL_EPHY_ID, 0xfffffff0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(mdio, rockchip_phy_tbl);
+
+MODULE_AUTHOR("David Wu <david.wu@rock-chips.com>");
+MODULE_DESCRIPTION("Rockchip Ethernet PHY driver");
+MODULE_LICENSE("GPL");