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.vmlinux_o | 98 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 scripts/Makefile.vmlinux_o (limited to 'scripts/Makefile.vmlinux_o') diff --git a/scripts/Makefile.vmlinux_o b/scripts/Makefile.vmlinux_o new file mode 100644 index 000000000..24a3a4fd2 --- /dev/null +++ b/scripts/Makefile.vmlinux_o @@ -0,0 +1,98 @@ +# SPDX-License-Identifier: GPL-2.0-only + +PHONY := __default +__default: vmlinux.o + +include include/config/auto.conf +include $(srctree)/scripts/Kbuild.include + +# for objtool +include $(srctree)/scripts/Makefile.lib + +# Generate a linker script to ensure correct ordering of initcalls for Clang LTO +# --------------------------------------------------------------------------- + +quiet_cmd_gen_initcalls_lds = GEN $@ + cmd_gen_initcalls_lds = \ + $(PYTHON3) $(srctree)/scripts/jobserver-exec \ + $(PERL) $(real-prereqs) > $@ + +.tmp_initcalls.lds: $(srctree)/scripts/generate_initcall_order.pl \ + vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE + $(call if_changed,gen_initcalls_lds) + +targets := .tmp_initcalls.lds + +ifdef CONFIG_LTO_CLANG +initcalls-lds := .tmp_initcalls.lds +endif + +# objtool for vmlinux.o +# --------------------------------------------------------------------------- +# +# For delay-objtool (IBT or LTO), objtool doesn't run on individual translation +# units. Instead it runs on vmlinux.o. +# +# For !delay-objtool + CONFIG_NOINSTR_VALIDATION, it runs on both translation +# units and vmlinux.o, with the latter only used for noinstr/unret validation. + +objtool-enabled := $(or $(delay-objtool),$(CONFIG_NOINSTR_VALIDATION)) + +ifeq ($(delay-objtool),y) +vmlinux-objtool-args-y += $(objtool-args-y) +else +vmlinux-objtool-args-$(CONFIG_OBJTOOL_WERROR) += --werror +endif + +vmlinux-objtool-args-$(CONFIG_NOINSTR_VALIDATION) += --noinstr \ + $(if $(or $(CONFIG_MITIGATION_UNRET_ENTRY),$(CONFIG_MITIGATION_SRSO)), --unret) + +# Only used for builds initiated by klp-build +vmlinux-objtool-args-$(if $(KLP_SYMIDS),y) += --klp-symids + +objtool-args = $(vmlinux-objtool-args-y) --link + +# Link of vmlinux.o used for section mismatch analysis +# --------------------------------------------------------------------------- + +vmlinux-o-ld-args-$(CONFIG_BUILTIN_MODULE_RANGES) += -Map=$@.map + +quiet_cmd_ld_vmlinux.o = LD $@ + cmd_ld_vmlinux.o = \ + $(LD) ${KBUILD_LDFLAGS} -r -o $@ \ + $(vmlinux-o-ld-args-y) \ + $(addprefix -T , $(initcalls-lds)) \ + --whole-archive vmlinux.a --no-whole-archive \ + --start-group $(KBUILD_VMLINUX_LIBS) --end-group \ + $(cmd_objtool) + +cmd_check_function_names = $(srctree)/scripts/check-function-names.sh $@ + +define rule_ld_vmlinux.o + $(call cmd_and_savecmd,ld_vmlinux.o) + $(call cmd,gen_objtooldep) + $(call cmd,check_function_names) +endef + + +vmlinux.o: $(initcalls-lds) vmlinux.a $(KBUILD_VMLINUX_LIBS) FORCE + $(call if_changed_rule,ld_vmlinux.o) + +targets += vmlinux.o + +# Add FORCE to the prerequisites of a target to force it to be always rebuilt. +# --------------------------------------------------------------------------- + +PHONY += FORCE +FORCE: + +# Read all saved command lines and dependencies for the $(targets) we +# may be building above, using $(if_changed{,_dep}). As an +# optimization, we don't need to read them if the target does not +# exist, we will rebuild anyway in that case. + +existing-targets := $(wildcard $(sort $(targets))) + +-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) + +.PHONY: $(PHONY) -- cgit v1.3.1