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/objdump-func | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100755 scripts/objdump-func (limited to 'scripts/objdump-func') diff --git a/scripts/objdump-func b/scripts/objdump-func new file mode 100755 index 000000000..7b15b873d --- /dev/null +++ b/scripts/objdump-func @@ -0,0 +1,45 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Disassemble a single function. +# +# usage: objdump-func [ ...] + +set -o errexit +set -o nounset + +OBJDUMP="${CROSS_COMPILE:-}objdump" + +command -v gawk >/dev/null 2>&1 || die "gawk isn't installed" + +usage() { + echo "usage: objdump-func [ ...]" >&2 + exit 1 +} + +[[ $# -lt 2 ]] && usage + +OBJ=$1; shift +FUNCS=("$@") + +${OBJDUMP} -wdr $OBJ | gawk -M -v _funcs="${FUNCS[*]}" ' + BEGIN { split(_funcs, funcs); } + /^$/ { func_match=0; } + /<.*>:/ { + f = gensub(/.*<(.*)>:/, "\\1", 1); + for (i in funcs) { + # match compiler-added suffixes like ".cold", etc + if (f ~ "^" funcs[i] "(\\..*)?") { + func_match = 1; + base = strtonum("0x" $1); + break; + } + } + } + { + if (func_match) { + addr = strtonum("0x" $1); + printf("%04x ", addr - base); + print; + } + }' -- cgit v1.3.1