selftests/bpf: Test packet range of pointers sharing an idgrafted

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 <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 194 insertions, 0 deletions

diff --git a/scripts/parse-maintainers.pl b/scripts/parse-maintainers.pl
new file mode 100755
index 000000000..2ca4eb3f1
--- /dev/null
+++ b/scripts/parse-maintainers.pl
@@ -0,0 +1,194 @@
+#!/usr/bin/perl -w
+# SPDX-License-Identifier: GPL-2.0
+
+use strict;
+use Getopt::Long qw(:config no_auto_abbrev);
+
+my $input_file = "MAINTAINERS";
+my $output_file = "MAINTAINERS.new";
+my $output_section = "SECTION.new";
+my $help = 0;
+my $order = 0;
+my $P = $0;
+
+if (!GetOptions(
+		'input=s' => \$input_file,
+		'output=s' => \$output_file,
+		'section=s' => \$output_section,
+		'order!' => \$order,
+		'h|help|usage' => \$help,
+	    )) {
+    die "$P: invalid argument - use --help if necessary\n";
+}
+
+if ($help != 0) {
+    usage();
+    exit 0;
+}
+
+sub usage {
+    print <<EOT;
+usage: $P [options] <pattern matching regexes>
+
+  --input => MAINTAINERS file to read (default: MAINTAINERS)
+  --output => sorted MAINTAINERS file to write (default: MAINTAINERS.new)
+  --section => new sorted MAINTAINERS file to write to (default: SECTION.new)
+  --order => Use the preferred section content output ordering (default: 0)
+    Preferred ordering of section output is:
+      M:  Person acting as a maintainer
+      R:  Person acting as a patch reviewer
+      L:  Mailing list where patches should be sent
+      S:  Maintenance status
+      W:  URI for general information
+      Q:  URI for patchwork tracking
+      B:  URI for bug tracking/submission
+      C:  URI for chat
+      P:  URI or file for subsystem specific coding styles
+      T:  SCM tree type and location
+      F:  File and directory pattern
+      X:  File and directory exclusion pattern
+      N:  File glob
+      K:  Keyword - patch content regex
+
+If <pattern match regexes> exist, then the sections that match the
+regexes are not written to the output file but are written to the
+section file.
+
+EOT
+}
+
+# sort comparison functions
+sub by_category($$) {
+    my ($a, $b) = @_;
+
+    $a = uc $a;
+    $b = uc $b;
+
+    # This always sorts last
+    $a =~ s/THE REST/ZZZZZZ/g;
+    $b =~ s/THE REST/ZZZZZZ/g;
+
+    return $a cmp $b;
+}
+
+sub by_pattern($$) {
+    my ($a, $b) = @_;
+    my $preferred_order = 'MRLSWQBCPTFXNK';
+
+    my $a1 = uc(substr($a, 0, 1));
+    my $b1 = uc(substr($b, 0, 1));
+
+    my $a_index = index($preferred_order, $a1);
+    my $b_index = index($preferred_order, $b1);
+
+    $a_index = 1000 if ($a_index == -1);
+    $b_index = 1000 if ($b_index == -1);
+
+    if (($a1 =~ /^F$/ && $b1 =~ /^F$/) ||
+	($a1 =~ /^X$/ && $b1 =~ /^X$/)) {
+	return $a cmp $b;
+    }
+
+    if ($a_index < $b_index) {
+	return -1;
+    } elsif ($a_index == $b_index) {
+	return 0;
+    } else {
+	return 1;
+    }
+}
+
+sub trim {
+    my $s = shift;
+    $s =~ s/\s+$//;
+    $s =~ s/^\s+//;
+    return $s;
+}
+
+sub alpha_output {
+    my ($hashref, $filename) = (@_);
+
+    return if ! scalar(keys %$hashref);
+
+    open(my $file, '>', "$filename") or die "$P: $filename: open failed - $!\n";
+    my $separator;
+    foreach my $key (sort by_category keys %$hashref) {
+	if ($key eq " ") {
+	    print $file $$hashref{$key};
+	} else {
+	    if (! defined $separator) {
+		$separator = "\n";
+	    } else {
+		print $file $separator;
+	    }
+	    print $file $key . "\n";
+	    if ($order) {
+		foreach my $pattern (sort by_pattern split('\n', %$hashref{$key})) {
+		    print $file ($pattern . "\n");
+		}
+	    } else {
+		foreach my $pattern (split('\n', %$hashref{$key})) {
+		    print $file ($pattern . "\n");
+		}
+	    }
+	}
+    }
+    close($file);
+}
+
+sub file_input {
+    my ($hashref, $filename) = (@_);
+
+    my $lastline = "";
+    my $case = " ";
+    $$hashref{$case} = "";
+
+    open(my $file, '<', "$filename") or die "$P: $filename: open failed - $!\n";
+
+    while (<$file>) {
+        my $line = $_;
+
+        # Pattern line?
+        if ($line =~ m/^([A-Z]):\s*(.*)/) {
+            $line = $1 . ":\t" . trim($2) . "\n";
+            if ($lastline eq "") {
+                $$hashref{$case} = $$hashref{$case} . $line;
+                next;
+            }
+            $case = trim($lastline);
+            exists $$hashref{$case} and die "Header '$case' already exists";
+            $$hashref{$case} = $line;
+            $lastline = "";
+            next;
+        }
+
+        if ($case eq " ") {
+            $$hashref{$case} = $$hashref{$case} . $lastline;
+            $lastline = $line;
+            next;
+        }
+        trim($lastline) eq "" or die ("Odd non-pattern line '$lastline' for '$case'");
+        $lastline = $line;
+    }
+    $$hashref{$case} = $$hashref{$case} . $lastline;
+    close($file);
+}
+
+my %hash;
+my %new_hash;
+
+file_input(\%hash, $input_file);
+
+foreach my $type (@ARGV) {
+    foreach my $key (keys %hash) {
+	if ($key =~ /$type/ || $hash{$key} =~ /$type/) {
+	    $new_hash{$key} = $hash{$key};
+	    delete $hash{$key};
+	}
+    }
+}
+
+alpha_output(\%hash, $output_file);
+alpha_output(\%new_hash, $output_section);
+
+exit(0);