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, 30 insertions, 0 deletions

diff --git a/drivers/usb/mtu3/Makefile b/drivers/usb/mtu3/Makefile
new file mode 100644
index 000000000..3bf8cbcc1
--- /dev/null
+++ b/drivers/usb/mtu3/Makefile
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0
+
+ccflags-$(CONFIG_USB_MTU3_DEBUG)	+= -DDEBUG
+
+# define_trace.h needs to know how to find our header
+CFLAGS_mtu3_trace.o	:= -I$(src)
+
+obj-$(CONFIG_USB_MTU3)	+= mtu3.o
+
+mtu3-y	:= mtu3_plat.o
+
+ifneq ($(CONFIG_TRACING),)
+	mtu3-y	+= mtu3_trace.o
+endif
+
+ifneq ($(filter y,$(CONFIG_USB_MTU3_HOST) $(CONFIG_USB_MTU3_DUAL_ROLE)),)
+	mtu3-y	+= mtu3_host.o
+endif
+
+ifneq ($(filter y,$(CONFIG_USB_MTU3_GADGET) $(CONFIG_USB_MTU3_DUAL_ROLE)),)
+	mtu3-y	+= mtu3_core.o mtu3_gadget_ep0.o mtu3_gadget.o mtu3_qmu.o
+endif
+
+ifneq ($(CONFIG_USB_MTU3_DUAL_ROLE),)
+	mtu3-y	+= mtu3_dr.o
+endif
+
+ifneq ($(CONFIG_DEBUG_FS),)
+	mtu3-y	+= mtu3_debugfs.o
+endif