From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id 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 Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- scripts/Makefile.btf | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 scripts/Makefile.btf (limited to 'scripts/Makefile.btf') diff --git a/scripts/Makefile.btf b/scripts/Makefile.btf new file mode 100644 index 000000000..a1812985a --- /dev/null +++ b/scripts/Makefile.btf @@ -0,0 +1,32 @@ +# SPDX-License-Identifier: GPL-2.0 + +pahole-ver := $(CONFIG_PAHOLE_VERSION) +pahole-flags-y := + +JOBS := $(patsubst -j%,%,$(filter -j%,$(MAKEFLAGS))) + +ifeq ($(call test-le, $(pahole-ver), 125),y) + +pahole-flags-y += --btf_gen_floats -j$(JOBS) + +pahole-flags-$(call test-ge, $(pahole-ver), 125) += --skip_encoding_btf_inconsistent_proto --btf_gen_optimized + +else + +# Switch to using --btf_features for v1.26 and later. +pahole-flags-$(call test-ge, $(pahole-ver), 126) = -j$(JOBS) --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func + +pahole-flags-$(call test-ge, $(pahole-ver), 131) += --btf_features=layout + +endif + +pahole-flags-$(CONFIG_PAHOLE_HAS_LANG_EXCLUDE) += --lang_exclude=rust + +export PAHOLE_FLAGS := $(pahole-flags-y) + +resolve-btfids-flags-y := +resolve-btfids-flags-$(CONFIG_WERROR) += --fatal_warnings +resolve-btfids-flags-$(if $(KBUILD_EXTMOD),y) += --distill_base +resolve-btfids-flags-$(if $(KBUILD_VERBOSE),y) += --verbose + +export RESOLVE_BTFIDS_FLAGS := $(resolve-btfids-flags-y) -- cgit v1.3.1