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, 41 insertions, 0 deletions

diff --git a/block/Makefile b/block/Makefile
new file mode 100644
index 000000000..e7bd320e3
--- /dev/null
+++ b/block/Makefile
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the kernel block layer
+#
+
+CONTEXT_ANALYSIS := y
+
+obj-y		:= bdev.o fops.o bio.o elevator.o blk-core.o blk-sysfs.o \
+			blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
+			blk-merge.o blk-timeout.o blk-lib.o blk-mq.o \
+			blk-mq-tag.o blk-mq-dma.o blk-stat.o \
+			blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \
+			genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o \
+			disk-events.o blk-ia-ranges.o early-lookup.o
+
+obj-$(CONFIG_BLK_ERROR_INJECTION) += error-injection.o
+obj-$(CONFIG_BLK_DEV_BSG_COMMON) += bsg.o
+obj-$(CONFIG_BLK_DEV_BSGLIB)	+= bsg-lib.o
+obj-$(CONFIG_BLK_CGROUP)	+= blk-cgroup.o
+obj-$(CONFIG_BLK_CGROUP_RWSTAT)	+= blk-cgroup-rwstat.o
+obj-$(CONFIG_BLK_CGROUP_FC_APPID) += blk-cgroup-fc-appid.o
+obj-$(CONFIG_BLK_DEV_THROTTLING)	+= blk-throttle.o
+obj-$(CONFIG_BLK_CGROUP_IOPRIO)	+= blk-ioprio.o
+obj-$(CONFIG_BLK_CGROUP_IOLATENCY)	+= blk-iolatency.o
+obj-$(CONFIG_BLK_CGROUP_IOCOST)	+= blk-iocost.o
+obj-$(CONFIG_MQ_IOSCHED_DEADLINE)	+= mq-deadline.o
+obj-$(CONFIG_MQ_IOSCHED_KYBER)	+= kyber-iosched.o
+bfq-y				:= bfq-iosched.o bfq-wf2q.o bfq-cgroup.o
+obj-$(CONFIG_IOSCHED_BFQ)	+= bfq.o
+
+obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o \
+				   bio-integrity-auto.o bio-integrity-fs.o
+obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
+obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
+obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
+obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
+obj-$(CONFIG_BLK_PM)		+= blk-pm.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o \
+					   blk-crypto-sysfs.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK)	+= blk-crypto-fallback.o
+obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED)	+= holder.o