poky/scripts/lib/wic/plugins/source/rootfs.py
Ricardo Ribalda Delgado 90164f0f3d wic: Fix permissions when using exclude or include path
When parameters include_path or exclude_path are passed to the rootfs
plugin, it will copy the partition content into a folder and make all
the modifications there.

This is done using copyhardlinktree(), which does not take into
consideration the content of the pseudo folder, which contains the
information about the right permissions and ownership of the folders.

This results in a rootfs owned by the user that is running the wic
command (usually UID 1000), which makes some rootfs unbootable.

This bug can be easily triggerd with the following .wks

part / --source rootfs --fstype=ext4 --exclude-path=home

And this sequence:

$ wic create test-permissions -e core-image-minimal -o test/
$ sudo mount test/test-permissions-202004080823-sda.direct.p1 /mnt
$ ls -la /mnt/etc/shadow

To fix this we copy the content of the pseudo folders to the new folder
and modify the pseudo database using the "pseudo -B" command.

If the rootfs is not a rootfs generated by bitbake a warning is shown
making the user aware that the permissions on the target might not match
what he expects.

WARNING: /tmp/test/../pseudo folder does not exist. Usernames and permissions will be invalid

Cc: Paul Barker <pbarker@konsulko.com>
(From OE-Core rev: fd739c15cdba221d9d497d3402b7d929c0be2ca4)

Signed-off-by: Ricardo Ribalda Delgado <ricardo@ribalda.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
2020-04-26 14:00:50 +01:00

147 lines
5.7 KiB
Python

#
# Copyright (c) 2014, Intel Corporation.
#
# SPDX-License-Identifier: GPL-2.0-only
#
# DESCRIPTION
# This implements the 'rootfs' source plugin class for 'wic'
#
# AUTHORS
# Tom Zanussi <tom.zanussi (at] linux.intel.com>
# Joao Henrique Ferreira de Freitas <joaohf (at] gmail.com>
#
import logging
import os
import shutil
import sys
from oe.path import copyhardlinktree
from wic import WicError
from wic.pluginbase import SourcePlugin
from wic.misc import get_bitbake_var, exec_native_cmd
logger = logging.getLogger('wic')
class RootfsPlugin(SourcePlugin):
"""
Populate partition content from a rootfs directory.
"""
name = 'rootfs'
@staticmethod
def __get_rootfs_dir(rootfs_dir):
if os.path.isdir(rootfs_dir):
return os.path.realpath(rootfs_dir)
image_rootfs_dir = get_bitbake_var("IMAGE_ROOTFS", rootfs_dir)
if not os.path.isdir(image_rootfs_dir):
raise WicError("No valid artifact IMAGE_ROOTFS from image "
"named %s has been found at %s, exiting." %
(rootfs_dir, image_rootfs_dir))
return os.path.realpath(image_rootfs_dir)
@staticmethod
def __get_pseudo(native_sysroot, rootfs, pseudo_dir):
pseudo = "export PSEUDO_PREFIX=%s/usr;" % native_sysroot
pseudo += "export PSEUDO_LOCALSTATEDIR=%s;" % pseudo_dir
pseudo += "export PSEUDO_PASSWD=%s;" % rootfs
pseudo += "export PSEUDO_NOSYMLINKEXP=1;"
pseudo += "%s " % get_bitbake_var("FAKEROOTCMD")
return pseudo
@classmethod
def do_prepare_partition(cls, part, source_params, cr, cr_workdir,
oe_builddir, bootimg_dir, kernel_dir,
krootfs_dir, native_sysroot):
"""
Called to do the actual content population for a partition i.e. it
'prepares' the partition to be incorporated into the image.
In this case, prepare content for legacy bios boot partition.
"""
if part.rootfs_dir is None:
if not 'ROOTFS_DIR' in krootfs_dir:
raise WicError("Couldn't find --rootfs-dir, exiting")
rootfs_dir = krootfs_dir['ROOTFS_DIR']
else:
if part.rootfs_dir in krootfs_dir:
rootfs_dir = krootfs_dir[part.rootfs_dir]
elif part.rootfs_dir:
rootfs_dir = part.rootfs_dir
else:
raise WicError("Couldn't find --rootfs-dir=%s connection or "
"it is not a valid path, exiting" % part.rootfs_dir)
part.rootfs_dir = cls.__get_rootfs_dir(rootfs_dir)
pseudo_dir = os.path.join(part.rootfs_dir, "../pseudo")
if not os.path.lexists(pseudo_dir):
logger.warn("%s folder does not exist. "
"Usernames and permissions will be invalid " % pseudo_dir)
pseudo_dir = None
new_rootfs = None
new_pseudo = None
# Handle excluded paths.
if part.exclude_path or part.include_path:
# We need a new rootfs directory we can delete files from. Copy to
# workdir.
new_rootfs = os.path.realpath(os.path.join(cr_workdir, "rootfs%d" % part.lineno))
if os.path.lexists(new_rootfs):
shutil.rmtree(os.path.join(new_rootfs))
copyhardlinktree(part.rootfs_dir, new_rootfs)
# Convert the pseudo directory to its new location
if (pseudo_dir):
new_pseudo = os.path.realpath(
os.path.join(cr_workdir, "pseudo%d" % part.lineno))
if os.path.lexists(new_pseudo):
shutil.rmtree(new_pseudo)
os.mkdir(new_pseudo)
shutil.copy(os.path.join(pseudo_dir, "files.db"),
os.path.join(new_pseudo, "files.db"))
pseudo_cmd = "%s -B -m %s -M %s" % (cls.__get_pseudo(native_sysroot,
new_rootfs,
new_pseudo),
part.rootfs_dir, new_rootfs)
exec_native_cmd(pseudo_cmd, native_sysroot)
for path in part.include_path or []:
copyhardlinktree(path, new_rootfs)
for orig_path in part.exclude_path or []:
path = orig_path
if os.path.isabs(path):
logger.error("Must be relative: --exclude-path=%s" % orig_path)
sys.exit(1)
full_path = os.path.realpath(os.path.join(new_rootfs, path))
# Disallow climbing outside of parent directory using '..',
# because doing so could be quite disastrous (we will delete the
# directory).
if not full_path.startswith(new_rootfs):
logger.error("'%s' points to a path outside the rootfs" % orig_path)
sys.exit(1)
if path.endswith(os.sep):
# Delete content only.
for entry in os.listdir(full_path):
full_entry = os.path.join(full_path, entry)
if os.path.isdir(full_entry) and not os.path.islink(full_entry):
shutil.rmtree(full_entry)
else:
os.remove(full_entry)
else:
# Delete whole directory.
shutil.rmtree(full_path)
part.prepare_rootfs(cr_workdir, oe_builddir,
new_rootfs or part.rootfs_dir, native_sysroot,
pseudo_dir = new_pseudo or pseudo_dir)