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/headers_install.sh | 75 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100755 scripts/headers_install.sh (limited to 'scripts/headers_install.sh') diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh new file mode 100755 index 000000000..2f1d1767c --- /dev/null +++ b/scripts/headers_install.sh @@ -0,0 +1,75 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 + +if [ $# -ne 2 ] +then + echo "Usage: headers_install.sh INFILE OUTFILE" + echo + echo "Prepares kernel header files for use by user space, by removing" + echo "all compiler.h definitions and #includes, removing any" + echo "#ifdef __KERNEL__ sections, and putting __underscores__ around" + echo "asm/inline/volatile keywords." + echo + echo "INFILE: header file to operate on" + echo "OUTFILE: output file which the processed header is written to" + + exit 1 +fi + +# Grab arguments +INFILE=$1 +OUTFILE=$2 +TMPFILE=$OUTFILE.tmp + +trap 'rm -f $OUTFILE $TMPFILE' EXIT + +# SPDX-License-Identifier with GPL variants must have "WITH Linux-syscall-note" +if [ -n "$(sed -n -e "/SPDX-License-Identifier:.*GPL-/{/WITH Linux-syscall-note/!p}" $INFILE)" ]; then + echo "error: $INFILE: missing \"WITH Linux-syscall-note\" for SPDX-License-Identifier" >&2 + exit 1 +fi + +sed -E -e ' + s/([[:space:](])(__user|__force|__iomem)[[:space:]]/\1/g + s/__attribute_const__([[:space:]]|$)/\1/g + s@^#include @@ + s/(^|[^a-zA-Z0-9])__packed([^a-zA-Z0-9_]|$)/\1__attribute__((packed))\2/g + s/(^|[[:space:](])(inline|asm|volatile)([[:space:](]|$)/\1__\2__\3/g + s@#(ifndef|define|endif[[:space:]]*/[*])[[:space:]]*_UAPI@#\1 @ + s/__ASSEMBLY__/__ASSEMBLER__/g +' $INFILE > $TMPFILE || exit 1 + +scripts/unifdef -U__KERNEL__ -D__EXPORTED_HEADERS__ $TMPFILE > $OUTFILE +[ $? -gt 1 ] && exit 1 + +# Remove /* ... */ style comments, and find CONFIG_ references in code +configs=$(sed -e ' +:comment + s:/\*[^*][^*]*:/*: + s:/\*\*\**\([^/]\):/*\1: + t comment + s:/\*\*/: : + t comment + /\/\*/! b check + N + b comment +:print + P + D +:check + s:^\(CONFIG_[[:alnum:]_]*\):\1\n: + t print + s:^[[:alnum:]_][[:alnum:]_]*:: + s:^[^[:alnum:]_][^[:alnum:]_]*:: + t check + d +' $OUTFILE) + +for c in $configs +do + echo "error: $INFILE: leak $c to user-space" >&2 + exit 1 +done + +rm -f $TMPFILE +trap - EXIT -- cgit v1.3.1