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>

2 files changed, 116 insertions, 0 deletions

diff --git a/include/media/davinci/vpfe_types.h b/include/media/davinci/vpfe_types.h
new file mode 100644
index 000000000..e65c9a48d
--- /dev/null
+++ b/include/media/davinci/vpfe_types.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2008-2009 Texas Instruments Inc
+ */
+#ifndef _VPFE_TYPES_H
+#define _VPFE_TYPES_H
+
+#ifdef __KERNEL__
+
+enum vpfe_pin_pol {
+	VPFE_PINPOL_POSITIVE,
+	VPFE_PINPOL_NEGATIVE
+};
+
+enum vpfe_hw_if_type {
+	/* BT656 - 8 bit */
+	VPFE_BT656,
+	/* BT1120 - 16 bit */
+	VPFE_BT1120,
+	/* Raw Bayer */
+	VPFE_RAW_BAYER,
+	/* YCbCr - 8 bit with external sync */
+	VPFE_YCBCR_SYNC_8,
+	/* YCbCr - 16 bit with external sync */
+	VPFE_YCBCR_SYNC_16,
+	/* BT656 - 10 bit */
+	VPFE_BT656_10BIT
+};
+
+/* interface description */
+struct vpfe_hw_if_param {
+	enum vpfe_hw_if_type if_type;
+	enum vpfe_pin_pol hdpol;
+	enum vpfe_pin_pol vdpol;
+};
+
+#endif
+#endif
diff --git a/include/media/davinci/vpif_types.h b/include/media/davinci/vpif_types.h
new file mode 100644
index 000000000..6cce1f09c
--- /dev/null
+++ b/include/media/davinci/vpif_types.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2011 Texas Instruments Inc
+ */
+#ifndef _VPIF_TYPES_H
+#define _VPIF_TYPES_H
+
+#include <linux/i2c.h>
+
+#define VPIF_CAPTURE_MAX_CHANNELS	2
+#define VPIF_DISPLAY_MAX_CHANNELS	2
+
+enum vpif_if_type {
+	VPIF_IF_BT656,
+	VPIF_IF_BT1120,
+	VPIF_IF_RAW_BAYER
+};
+
+struct vpif_interface {
+	enum vpif_if_type if_type;
+	unsigned hd_pol:1;
+	unsigned vd_pol:1;
+	unsigned fid_pol:1;
+};
+
+struct vpif_subdev_info {
+	const char *name;
+	struct i2c_board_info board_info;
+};
+
+struct vpif_output {
+	struct v4l2_output output;
+	const char *subdev_name;
+	u32 input_route;
+	u32 output_route;
+};
+
+struct vpif_display_chan_config {
+	const struct vpif_output *outputs;
+	int output_count;
+	bool clip_en;
+};
+
+struct vpif_display_config {
+	int (*set_clock)(int, int);
+	struct vpif_subdev_info *subdevinfo;
+	int subdev_count;
+	int i2c_adapter_id;
+	struct vpif_display_chan_config chan_config[VPIF_DISPLAY_MAX_CHANNELS];
+	const char *card_name;
+};
+
+struct vpif_input {
+	struct v4l2_input input;
+	char *subdev_name;
+	u32 input_route;
+	u32 output_route;
+};
+
+struct vpif_capture_chan_config {
+	struct vpif_interface vpif_if;
+	struct vpif_input *inputs;
+	int input_count;
+};
+
+struct vpif_capture_config {
+	int (*setup_input_channel_mode)(int);
+	int (*setup_input_path)(int, const char *);
+	struct vpif_capture_chan_config chan_config[VPIF_CAPTURE_MAX_CHANNELS];
+	struct vpif_subdev_info *subdev_info;
+	int subdev_count;
+	int i2c_adapter_id;
+	const char *card_name;
+
+	struct v4l2_async_connection *asd[VPIF_CAPTURE_MAX_CHANNELS];
+	int asd_sizes[VPIF_CAPTURE_MAX_CHANNELS];
+};
+#endif /* _VPIF_TYPES_H */