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 --- usr/include/headers_check.pl | 96 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100755 usr/include/headers_check.pl (limited to 'usr/include/headers_check.pl') diff --git a/usr/include/headers_check.pl b/usr/include/headers_check.pl new file mode 100755 index 000000000..6cd6eb652 --- /dev/null +++ b/usr/include/headers_check.pl @@ -0,0 +1,96 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 +# +# headers_check.pl execute a number of trivial consistency checks +# +# Usage: headers_check.pl dir [files...] +# dir: dir to look for included files +# files: list of files to check +# +# The script reads the supplied files line by line and: +# +# 1) for each include statement it checks if the +# included file actually exists. +# Only include files located in asm* and linux* are checked. +# The rest are assumed to be system include files. +# +# 2) It is checked that prototypes does not use "extern" +# +# 3) Check for leaked CONFIG_ symbols + +use warnings; +use strict; +use File::Basename; + +my ($dir, @files) = @ARGV; + +my $ret = 0; +my $line; +my $lineno = 0; +my $filename; + +foreach my $file (@files) { + $filename = $file; + + open(my $fh, '<', $filename) + or die "$filename: $!\n"; + $lineno = 0; + while ($line = <$fh>) { + $lineno++; + &check_include(); + &check_asm_types(); + &check_declarations(); + } + close $fh; +} +exit $ret; + +sub check_include +{ + if ($line =~ m/^\s*#\s*include\s+<((asm|linux).*)>/) { + my $inc = $1; + my $found; + $found = stat($dir . "/" . $inc); + if (!$found) { + printf STDERR "$filename:$lineno: included file '$inc' is not exported\n"; + $ret = 1; + } + } +} + +sub check_declarations +{ + # soundcard.h is what it is + if ($line =~ m/^void seqbuf_dump\(void\);/) { + return; + } + # drm headers are being C++ friendly + if ($line =~ m/^extern "C"/) { + return; + } + if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) { + printf STDERR "$filename:$lineno: " . + "userspace cannot reference function or " . + "variable defined in the kernel\n"; + $ret = 1; + } +} + +my $linux_asm_types; +sub check_asm_types +{ + if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) { + return; + } + if ($lineno == 1) { + $linux_asm_types = 0; + } elsif ($linux_asm_types >= 1) { + return; + } + if ($line =~ m/^\s*#\s*include\s+/) { + $linux_asm_types = 1; + printf STDERR "$filename:$lineno: " . + "include of is preferred over \n"; + $ret = 1; + } +} -- cgit v1.3.1