selftests/bpf: Test packet range of pointers sharing an idgrafted

Add tests where two packet pointers share an id and tightening one
pointer's umax from its var_off would put it less than their constant
distance from the other's umax: with an index & 0x38 capped at 50, the
base pointer keeps umax 50, so the pointer 8 bytes further on must keep
umax 58, even though its known bits allow at most 56.

These refused a valid program or accepted an out-of-bounds access before
the fix:

- check the advanced copy, load through the base: valid, was refused;
- check the base, load the byte at base + 1 through a copy advanced by
  8: was accepted;
- check base + 4, load 4 bytes at base + 2 through base + 8: reads two
  bytes past the checked range, was accepted;
- the same as the second with data_meta pointers checked against data:
  was accepted.

These pass with and without the fix and cover nearby paths:

- subtract an unknown scalar from a checked pointer and load below it
  (the range is kept across a new id);
- reach a load through two paths whose checks cover 8 and 7 bytes after
  the loaded pointer; the second path must not be pruned by the first;
- spill a copy of a pointer, check the pointer, fill the copy and load
  one byte past the checked range: the load is refused, and the copy
  has the range of the check.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 116 insertions, 0 deletions

diff --git a/include/sound/ac97/codec.h b/include/sound/ac97/codec.h
new file mode 100644
index 000000000..69aa7ee15
--- /dev/null
+++ b/include/sound/ac97/codec.h
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ *  Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr>
+ */
+
+#ifndef __SOUND_AC97_CODEC2_H
+#define __SOUND_AC97_CODEC2_H
+
+#include <linux/device.h>
+
+#define AC97_ID(vendor_id1, vendor_id2) \
+	((((vendor_id1) & 0xffff) << 16) | ((vendor_id2) & 0xffff))
+#define AC97_DRIVER_ID(vendor_id1, vendor_id2, mask_id1, mask_id2, _data) \
+	{ .id = (((vendor_id1) & 0xffff) << 16) | ((vendor_id2) & 0xffff), \
+	  .mask = (((mask_id1) & 0xffff) << 16) | ((mask_id2) & 0xffff), \
+	  .data = (_data) }
+
+struct ac97_controller;
+struct clk;
+
+/**
+ * struct ac97_id - matches a codec device and driver on an ac97 bus
+ * @id: The significant bits if the codec vendor ID1 and ID2
+ * @mask: Bitmask specifying which bits of the id field are significant when
+ *	  matching. A driver binds to a device when :
+ *        ((vendorID1 << 8 | vendorID2) & (mask_id1 << 8 | mask_id2)) == id.
+ * @data: Private data used by the driver.
+ */
+struct ac97_id {
+	unsigned int		id;
+	unsigned int		mask;
+	void			*data;
+};
+
+/**
+ * struct ac97_codec_device - a ac97 codec
+ * @dev: the core device
+ * @vendor_id: the vendor_id of the codec, as sensed on the AC-link
+ * @num: the codec number, 0 is primary, 1 is first slave, etc ...
+ * @clk: the clock BIT_CLK provided by the codec
+ * @ac97_ctrl: ac97 digital controller on the same AC-link
+ *
+ * This is the device instantiated for each codec living on a AC-link. There are
+ * normally 0 to 4 codec devices per AC-link, and all of them are controlled by
+ * an AC97 digital controller.
+ */
+struct ac97_codec_device {
+	struct device		dev;
+	unsigned int		vendor_id;
+	unsigned int		num;
+	struct clk		*clk;
+	struct ac97_controller	*ac97_ctrl;
+};
+
+/**
+ * struct ac97_codec_driver - a ac97 codec driver
+ * @driver: the device driver structure
+ * @probe: the function called when a ac97_codec_device is matched
+ * @remove: the function called when the device is unbound/removed
+ * @shutdown: shutdown function (might be NULL)
+ * @id_table: ac97 vendor_id match table, { } member terminated
+ */
+struct ac97_codec_driver {
+	struct device_driver	driver;
+	int			(*probe)(struct ac97_codec_device *);
+	void			(*remove)(struct ac97_codec_device *dev);
+	void			(*shutdown)(struct ac97_codec_device *);
+	const struct ac97_id	*id_table;
+};
+
+static inline struct ac97_codec_device *to_ac97_device(struct device *d)
+{
+	return container_of(d, struct ac97_codec_device, dev);
+}
+
+#define to_ac97_driver(__drv) container_of_const(__drv, struct ac97_codec_driver, driver)
+
+#if IS_ENABLED(CONFIG_AC97_BUS_NEW)
+int snd_ac97_codec_driver_register(struct ac97_codec_driver *drv);
+void snd_ac97_codec_driver_unregister(struct ac97_codec_driver *drv);
+#else
+static inline int
+snd_ac97_codec_driver_register(struct ac97_codec_driver *drv)
+{
+	return 0;
+}
+static inline void
+snd_ac97_codec_driver_unregister(struct ac97_codec_driver *drv)
+{
+}
+#endif
+
+
+static inline struct device *
+ac97_codec_dev2dev(struct ac97_codec_device *adev)
+{
+	return &adev->dev;
+}
+
+static inline void *ac97_get_drvdata(struct ac97_codec_device *adev)
+{
+	return dev_get_drvdata(ac97_codec_dev2dev(adev));
+}
+
+static inline void ac97_set_drvdata(struct ac97_codec_device *adev,
+				    void *data)
+{
+	dev_set_drvdata(ac97_codec_dev2dev(adev), data);
+}
+
+static inline void *snd_ac97_codec_get_platdata(const struct ac97_codec_device *adev)
+{
+	return NULL;
+}
+
+#endif