Skip to content

fix: use xcat-compat initrd for Ubuntu pre-16.04.2 ppc64el in copycds #14

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
viniciusferrao wants to merge 1 commit into
base: master
Choose a base branch
from
Draft

fix: use xcat-compat initrd for Ubuntu pre-16.04.2 ppc64el in copycds #14

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
350 changes: 344 additions & 6 deletions xCAT-server/lib/xcat/plugins/debian.pm
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,10 @@ use lib "$::XCATROOT/lib/perl";
use Storable qw(dclone);
use Sys::Syslog;
use File::Temp qw/tempdir/;
use Cwd qw/realpath/;
use Fcntl qw(:DEFAULT);
use File::Copy qw(copy);
use File::Basename;
use xCAT::Table;
use xCAT::Utils;
use xCAT::SvrUtils;
Expand Down Expand Up @@ -190,6 +194,93 @@ sub copyAndAddCustomizations {
system("find . |cpio -o -H newc | gzip -c - -9 >> $dest");
}

# Safely unlink a file only if it is a regular file (not a symlink) and
# its resolved path is under the expected install root.
sub _safe_unlink
{
my ($path, $expected_root) = @_;
return unless $expected_root;
return unless -f $path and ! -l $path;
my $real = realpath($path);
return unless $real;
if ($real eq $expected_root or index($real, "$expected_root/") == 0)
{
unlink($path);
}
}

# Copy src to an O_EXCL-opened dst filehandle with full error checking.
# Loops on short writes, distinguishes read errors from EOF, checks
# close on both handles, and verifies size matches source.
# Returns 1 on success, 0 on failure.
# Safely restore a backup to its original path, validating that
# the target remains under the expected install root and no
# ancestor is a symlink.
sub _safe_restore
{
my ($backup, $original, $expected_root) = @_;
return 0 unless $expected_root and -f $backup;

# Validate ancestors of the target
my $real_parent = realpath(File::Basename::dirname($original));
return 0 unless $real_parent;
return 0 unless $real_parent eq $expected_root or
index($real_parent, "$expected_root/") == 0;

# Check no symlink at the target itself.
# Never delete the backup — it may be the only recovery copy.
if (-l $original)
{
return 0;
}

return rename($backup, $original) ? 1 : 0;
}

sub _safe_copy_to_excl
{
my ($src_path, $dst_fh) = @_;
my $src_fh;
unless (open($src_fh, '<', $src_path))
{
return 0;
}
binmode($src_fh);
binmode($dst_fh);

my $total = 0;
my $buf;
while (1)
{
my $n = sysread($src_fh, $buf, 65536);
if (!defined $n)
{
close($src_fh);
return 0;
}
last if $n == 0;

my $written = 0;
while ($written < $n)
{
my $w = syswrite($dst_fh, $buf, $n - $written, $written);
if (!defined $w)
{
close($src_fh);
return 0;
}
$written += $w;
}
$total += $n;
}
close($src_fh) or return 0;
close($dst_fh) or return 0;

# Verify size matches source
my $src_size = -s $src_path;
return ($total == $src_size) ? 1 : 0;
}

sub copycd
{
my $request = shift;
Expand Down Expand Up @@ -357,6 +448,117 @@ sub copycd
}
%{$request} = (); #clear request we've got it.

# Preflight: Ubuntu pre-16.04.2 on ppc64el requires a netboot-capable
# initrd from the xcat-compat package. All validation runs before any
# files are written so we don't corrupt an existing install tree.
my $compat_initrd;
my $compat_expected_root;
if ($arch eq "ppc64el" and $detdistname =~ /^ubuntu(\d+)\.(\d+)\.?(\d*)/)
{
my ($major, $minor, $point) = ($1, $2, $3 || 0);
if ($major < 16 or ($major == 16 and $minor == 4 and $point < 2))
{
my $compat_ver = ($point > 0) ? "$major.$minor.$point" : "$major.$minor";
$compat_initrd = "$::XCATROOT/share/xcat/netboot/ubuntu/initrd/ubuntu${compat_ver}.ppc64el.gz";

if (! -f $compat_initrd or ! -r $compat_initrd or ! -s $compat_initrd)
{
if ($noosimage)
{
$callback->({ warning => ["Ubuntu $detdistname on ppc64el: xcat-compat package not installed. Media will be copied but netboot osimages will not work until xcat-compat is installed and copycds is re-run without -o."] });
# Clear compat_initrd so replacement is skipped, but
# mark paths for cleanup so mkinstall can't find the
# known-bad ISO initrd and silently produce a non-booting image.
$compat_initrd = undef;
}
else
{
$callback->({ error => "Ubuntu $detdistname on ppc64el requires a netboot-capable initrd not included in the server ISO. Install the xcat-compat package (yum install xCAT-compat or apt install xcat-compat) and run copycds again." });
return;
}
}

# Resolve the install root early. realpath handles symlinked
# /install (e.g. pointing to external storage) correctly.
# We validate target paths against this resolved root, not
# against the raw path, so symlinked installdir is allowed
# but symlinks WITHIN the distro tree are rejected.
$compat_expected_root = realpath($installroot) || $installroot;

# Validate existing target path ancestors for symlinks
# within the distro tree (below installroot).
my @target_dirs = (
"$installroot/$distname/$arch/install/netboot",
"$installroot/$distname/$arch/install/netboot/ubuntu-installer/$arch",
);
foreach my $tdir (@target_dirs)
{
# Only check components below the resolved installroot
my $relative = $tdir;
$relative =~ s/^\Q$installroot\E\/?//;
my $walk = realpath($installroot) || $installroot;
foreach my $part (split('/', $relative))
{
next unless $part;
$walk .= "/$part";
last unless -e $walk;
if (-l $walk)
{
$callback->({ error => "Symlink detected at $walk within install tree, refusing to proceed." });
return;
}
}
}
}
}

# Track all candidate initrd paths before ISO copy so we can
# restore/clean up on any failure. Runs for all affected ppc64el
# media, including noosimage, so we never lose existing working initrds.
my @compat_initrd_backups;
my @compat_initrd_created;
my $is_affected_ppc64el = ($arch eq "ppc64el" and $detdistname =~ /^ubuntu(\d+)\.(\d+)\.?(\d*)/ and
($1 < 16 or ($1 == 16 and $2 == 4 and ($3 || 0) < 2)));
if ($is_affected_ppc64el)
{
my @paths = (
"$installroot/$distname/$arch/install/netboot/initrd.gz",
"$installroot/$distname/$arch/install/netboot/ubuntu-installer/$arch/initrd.gz",
);
foreach my $p (@paths)
{
if (-l $p)
{
$callback->({ error => "Existing symlink at $p, refusing to proceed." });
return;
}
elsif (-f $p)
{
# Store backups in the parent of the distro tree (same
# filesystem for atomic rename, but outside cpio target).
my $basename = $p;
$basename =~ s/[\/]/_/g;
my $bak = "$installroot/.xcat-copycds-bak-$$-$basename";
my $bak_ok = 0;
if (sysopen(my $dst_fh, $bak, O_WRONLY|O_CREAT|O_EXCL, 0600))
{
$bak_ok = _safe_copy_to_excl($p, $dst_fh);
}
if (!$bak_ok)
{
$callback->({ error => "Failed to back up existing initrd at $p. Cannot safely proceed with copycds." });
unlink($_->{backup}) for @compat_initrd_backups;
return;
}
push @compat_initrd_backups, { original => $p, backup => $bak };
}
elsif (! -e $p)
{
push @compat_initrd_created, $p;
}
}
}

$callback->(
{ data => "Copying media to $installroot/$distname/$arch" });
my $omask = umask 0022;
Expand Down Expand Up @@ -403,7 +605,23 @@ sub copycd
$callback->({ sinfo => "$fout" });
++$copied;
}
exit;
close(PIPE);
exit($? ? 1 : 0);
}

# Check cpio status immediately before any post-copy mutations.
if ($rc != 0)
{
$callback->({ error => "Media copy operation failed, status $rc" });
foreach my $b (@compat_initrd_backups)
{
unless (_safe_restore($b->{backup}, $b->{original}, $compat_expected_root)) { $callback->({ warning => ["Failed to restore backup $b->{backup} to $b->{original}. Manual recovery may be needed."] }); }
}
foreach my $p (@compat_initrd_created)
{
_safe_unlink($p, $compat_expected_root);
}
return;
}

# system(
Expand Down Expand Up @@ -432,12 +650,132 @@ sub copycd
system("cp install.*/vmlinuz $installroot/$distname/$arch/install/netboot/.");
}

if ($rc != 0)
# For noosimage ppc64el affected media without compat: restore
# pre-existing initrds from backup (preserving whatever state existed
# before this copycds run) and delete only files created by this cpio.
# This avoids both destroying a working compat initrd AND leaving a
# newly-copied bad ISO initrd discoverable by mkinstall.
if (!$compat_initrd and $is_affected_ppc64el)
{
$callback->({ error => "Media copy operation failed, status $rc" });
foreach my $b (@compat_initrd_backups)
{
unless (_safe_restore($b->{backup}, $b->{original}, $compat_expected_root)) { $callback->({ warning => ["Failed to restore backup $b->{backup} to $b->{original}. Manual recovery may be needed."] }); }
}
_safe_unlink($_, $compat_expected_root) for @compat_initrd_created;
}
else

{
# Replace the broken ppc64el initrd with the compat version.
# Runs only after media copy succeeds. Uses atomic temp+rename
# and validates canonical paths to prevent symlink traversal.
# On failure, restores backed-up initrd files from before the
# ISO copy so a re-run of copycds doesn't degrade an existing
# working install tree.
# Path validation (ancestor symlinks, containment) already done
# in preflight before any files were written.
if ($compat_initrd)
{
my @target_dirs = (
"$installroot/$distname/$arch/install/netboot",
"$installroot/$distname/$arch/install/netboot/ubuntu-installer/$arch",
);
my $copy_ok = 1;
my @staged;
foreach my $tdir (@target_dirs)
{
# Re-walk path components after cpio to catch symlinks
# that the media copy may have introduced.
my $relative = $tdir;
$relative =~ s/^\Q$installroot\E\/?//;
my $walk = realpath($installroot) || $installroot;
my $symlink_found = 0;
foreach my $part (split('/', $relative))
{
next unless $part;
$walk .= "/$part";
last unless -e $walk;
if (-l $walk)
{
$callback->({ error => "Symlink at $walk introduced by media copy, refusing to write compat initrd." });
$symlink_found = 1;
last;
}
}
if ($symlink_found)
{
$copy_ok = 0;
last;
}

mkpath($tdir);

# Verify resolved path stays under the install tree
my $real_tdir = realpath($tdir);
if (!$real_tdir or ($real_tdir ne $compat_expected_root
and index($real_tdir, "$compat_expected_root/") != 0))
{
$callback->({ error => "Target path $tdir resolves outside install tree, refusing to write." });
$copy_ok = 0;
last;
}

my $target = "$real_tdir/initrd.gz";

if (-l $target)
{
$callback->({ error => "Symlink detected at $target, refusing to overwrite." });
$copy_ok = 0;
last;
}

# Copy through O_EXCL filehandle with full error checking.
my $tmp = "$real_tdir/initrd.gz.tmp.$$";
my $tmp_ok = 0;
if (sysopen(my $dst_fh, $tmp, O_WRONLY|O_CREAT|O_EXCL, 0644))
{
$tmp_ok = _safe_copy_to_excl($compat_initrd, $dst_fh);
}
if (!$tmp_ok or ! -s $tmp)
{
unlink($tmp);
$callback->({ error => "Failed to copy compat initrd to $tdir." });
$copy_ok = 0;
last;
}
push @staged, { tmp => $tmp, target => "$real_tdir/initrd.gz" };
}

if ($copy_ok)
{
foreach my $s (@staged)
{
unless (rename($s->{tmp}, $s->{target}))
{
$callback->({ error => "Failed to rename compat initrd to $s->{target}: $!" });
unlink($s->{tmp});
$copy_ok = 0;
}
}
}

unless ($copy_ok)
{
unlink($_->{tmp}) for @staged;
# Restore backed-up initrd files so the existing tree isn't degraded
foreach my $b (@compat_initrd_backups)
{
unless (_safe_restore($b->{backup}, $b->{original}, $compat_expected_root)) { $callback->({ warning => ["Failed to restore backup $b->{backup} to $b->{original}. Manual recovery may be needed."] }); }
}
# Delete initrd files that didn't exist before the ISO copy,
# so mkinstall doesn't find the broken ISO initrd at the
# higher-priority ubuntu-installer path.
_safe_unlink($_, $compat_expected_root) for @compat_initrd_created;
return;
}
# Clean up backups on success
unlink($_->{backup}) for @compat_initrd_backups;
$callback->({ data => "Replaced ppc64el initrd with netboot-capable version from xcat-compat package." });
}
my $osdistroname = $distname . "-" . $arch;
my $temppath = "$installroot/$distname/$arch";
my @ret = xCAT::SvrUtils->update_osdistro_table($distname, $arch, $temppath, $osdistroname);
Expand Down Expand Up @@ -818,8 +1156,8 @@ sub mkinstall {

if ($arch =~ /ppc64/i and !(-e "$pkgdir/install/netboot/initrd.gz") and
!(-e "$pkgdir/install/netboot/ubuntu-installer/$darch/initrd.gz")) {
xCAT::MsgUtils->report_node_error($callback, $node,
"The network boot initrd.gz is not found in $pkgdir/install/netboot. This is provided by Ubuntu, please download and retry."
xCAT::MsgUtils->report_node_error($callback, $node,
"The network boot initrd.gz is not found in $pkgdir/install/netboot. For Ubuntu pre-16.04.2 on ppc64el, install the xcat-compat package and re-run copycds."
);
next;
}
Expand Down