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/mk_elfconfig.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 scripts/mod/mk_elfconfig.c (limited to 'scripts/mod/mk_elfconfig.c') diff --git a/scripts/mod/mk_elfconfig.c b/scripts/mod/mk_elfconfig.c new file mode 100644 index 000000000..e8cee4e4b --- /dev/null +++ b/scripts/mod/mk_elfconfig.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +int +main(int argc, char **argv) +{ + unsigned char ei[EI_NIDENT]; + + if (fread(ei, 1, EI_NIDENT, stdin) != EI_NIDENT) { + fprintf(stderr, "Error: input truncated\n"); + return 1; + } + if (memcmp(ei, ELFMAG, SELFMAG) != 0) { + fprintf(stderr, "Error: not ELF\n"); + return 1; + } + switch (ei[EI_CLASS]) { + case ELFCLASS32: + printf("#define KERNEL_ELFCLASS ELFCLASS32\n"); + break; + case ELFCLASS64: + printf("#define KERNEL_ELFCLASS ELFCLASS64\n"); + break; + default: + exit(1); + } + + return 0; +} -- cgit v1.3.1