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/mod/Makefile | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 scripts/mod/Makefile (limited to 'scripts/mod/Makefile') diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile new file mode 100644 index 000000000..c729bc936 --- /dev/null +++ b/scripts/mod/Makefile @@ -0,0 +1,27 @@ +# SPDX-License-Identifier: GPL-2.0 +CFLAGS_REMOVE_empty.o += $(CC_FLAGS_LTO) + +hostprogs-always-y += modpost mk_elfconfig +always-y += empty.o + +modpost-objs := modpost.o file2alias.o sumversion.o symsearch.o + +devicetable-offsets-file := devicetable-offsets.h + +$(obj)/$(devicetable-offsets-file): $(obj)/devicetable-offsets.s FORCE + $(call filechk,offsets,__DEVICETABLE_OFFSETS_H__) + +targets += $(devicetable-offsets-file) devicetable-offsets.s + +# dependencies on generated files need to be listed explicitly + +$(obj)/modpost.o $(obj)/file2alias.o $(obj)/sumversion.o $(obj)/symsearch.o: $(obj)/elfconfig.h +$(obj)/file2alias.o: $(obj)/$(devicetable-offsets-file) + +quiet_cmd_elfconfig = MKELF $@ + cmd_elfconfig = $(obj)/mk_elfconfig < $< > $@ + +$(obj)/elfconfig.h: $(obj)/empty.o $(obj)/mk_elfconfig FORCE + $(call if_changed,elfconfig) + +targets += elfconfig.h -- cgit v1.3.1