Merge Cherry-pick: MountRule: Aligning behavior with apparmor_parser

Mount Rules with options in { remount, [make-] { [r]unbindable, [r]shared, [r]private, and [r]slave }} do not support specifying a source. This commit aligns utils implementation to apparmor_parser's, which prohibits having a both source and a destination simultaneously, instad of just prohibiting source.

Therefore, both `mount options=(unbindable) /a,` and `mount options=(unbindable) -> /a,` are now supported (and equivalent for apparmor_parser). However, `mount options=(unbindable) /a -> /b,` is invalid.

For the same reason, specifying a fstype in these cases is also prohibited.

Similarly, we prohibit to specify a fstype for bind mount rules.

Fixes: https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/2065685

(cherry picked from commit 60acc4a405)

Signed-off-by: Maxime Bélair <maxime.belair@canonical.com>

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1237
Approved-by: Georgia Garcia <georgia.garcia@canonical.com>
Merged-by: Georgia Garcia <georgia.garcia@canonical.com>
This commit is contained in:
Georgia Garcia 2024-05-22 12:34:01 +00:00
commit fcd02fb69b
3 changed files with 51 additions and 42 deletions

View file

@ -25,15 +25,18 @@ _ = init_translation()
# TODO : Apparmor remount logs are displayed as mount (with remount flag). Profiles generated with aa-genprof are therefore mount rules. It could be interesting to make them remount rules.
flags_keywords = [
# keep in sync with parser/mount.cc mnt_opts_table!
'ro', 'r', 'read-only', 'rw', 'w', 'suid', 'nosuid', 'dev', 'nodev', 'exec', 'noexec', 'sync', 'async', 'remount',
'mand', 'nomand', 'dirsync', 'symfollow', 'nosymfollow', 'atime', 'noatime', 'diratime', 'nodiratime', 'bind', 'B',
'move', 'M', 'rbind', 'R', 'verbose', 'silent', 'loud', 'acl', 'noacl', 'unbindable', 'make-unbindable', 'runbindable',
'make-runbindable', 'private', 'make-private', 'rprivate', 'make-rprivate', 'slave', 'make-slave', 'rslave', 'make-rslave',
'shared', 'make-shared', 'rshared', 'make-rshared', 'relatime', 'norelatime', 'iversion', 'noiversion', 'strictatime',
'nostrictatime', 'lazytime', 'nolazytime', 'user', 'nouser',
'([A-Za-z0-9])',
flags_bind_mount = {'B', 'bind', 'R', 'rbind'}
flags_change_propagation = {
'remount', 'unbindable', 'shared', 'private', 'slave', 'runbindable', 'rshared', 'rprivate', 'rslave',
'make-unbindable', 'make-shared', 'make-private', 'make-slave', 'make-runbindable', 'make-rshared', 'make-rprivate',
'make-rslave'
}
# keep in sync with parser/mount.cc mnt_opts_table!
flags_keywords = list(flags_bind_mount) + list(flags_change_propagation) + [
'ro', 'r', 'read-only', 'rw', 'w', 'suid', 'nosuid', 'dev', 'nodev', 'exec', 'noexec', 'sync', 'async', 'mand',
'nomand', 'dirsync', 'symfollow', 'nosymfollow', 'atime', 'noatime', 'diratime', 'nodiratime', 'move', 'M',
'verbose', 'silent', 'loud', 'acl', 'noacl', 'relatime', 'norelatime', 'iversion', 'noiversion', 'strictatime',
'nostrictatime', 'lazytime', 'nolazytime', 'user', 'nouser', '([A-Za-z0-9])',
]
join_valid_flags = '|'.join(flags_keywords)
@ -112,6 +115,7 @@ class MountRule(BaseRule):
self.is_options_equal = options[0] if not self.all_options else None
self.source, self.all_source = self._aare_or_all(source, 'source', is_path=False, log_event=log_event)
self.dest, self.all_dest = self._aare_or_all(dest, 'dest', is_path=False, log_event=log_event)
if not self.all_fstype and self.is_fstype_equal not in ('=', 'in'):
raise AppArmorBug(f'Invalid is_fstype_equal : {self.is_fstype_equal}')
@ -120,11 +124,14 @@ class MountRule(BaseRule):
if self.operation != 'mount' and not self.all_source:
raise AppArmorException(f'Operation {self.operation} cannot have a source')
flags_forbidden_with_source = {'remount', 'unbindable', 'shared', 'private', 'slave', 'runbindable', 'rshared', 'rprivate', 'rslave'}
if self.operation == 'mount' and not self.all_source and not self.all_options and flags_forbidden_with_source & self.options != set():
raise AppArmorException(f'Operation {flags_forbidden_with_source & self.options} cannot have a source. Source = {self.source}')
if self.operation == 'mount' and not self.all_options and flags_change_propagation & self.options != set():
if not (self.all_source or self.all_dest):
raise AppArmorException(f'Operation {flags_change_propagation & self.options} cannot specify a source. Source = {self.source}')
elif not self.all_fstype:
raise AppArmorException(f'Operation {flags_change_propagation & self.options} cannot specify a fstype. Fstype = {self.fstype}')
self.dest, self.all_dest = self._aare_or_all(dest, 'dest', is_path=False, log_event=log_event)
if self.operation == 'mount' and not self.all_options and flags_bind_mount & self.options != set() and not self.all_fstype:
raise AppArmorException(f'Bind mount rules cannot specify a fstype. Fstype = {self.fstype}')
self.can_glob = not self.all_source and not self.all_dest and not self.all_options

View file

@ -43,12 +43,12 @@ class MountTestParse(AATest):
('mount @{mntpnt},', MountRule('mount', MountRule.ALL, MountRule.ALL, '@{mntpnt}', MountRule.ALL, False, False, False, '' )),
('mount /a,', MountRule('mount', MountRule.ALL, MountRule.ALL, '/a', MountRule.ALL, False, False, False, '' )),
('mount fstype=(ext3, ext4) /a -> /b,', MountRule('mount', ('=', ['ext3', 'ext4']), MountRule.ALL, '/a', '/b', False, False, False, '' )),
('mount fstype=(ext3, ext4) options=(ro, rbind) /a -> /b,', MountRule('mount', ('=', ['ext3', 'ext4']), ('=', ('ro', 'rbind')), '/a', '/b', False, False, False, '' )),
('mount fstype=(ext3, ext4) options=(ro, rbind) /a -> /b, #cmt', MountRule('mount', ('=', ['ext3', 'ext4']), ('=', ('ro', 'rbind')), '/a', '/b', False, False, False, ' #cmt')),
('mount fstype=({ext3,ext4}) options in (ro, rbind) /a -> /b,', MountRule('mount', ('=', ['{ext3,ext4}']), ('in', ('ro', 'rbind')), '/a', '/b', False, False, False, '' )),
('mount fstype in (ext3, ext4) options=(ro, rbind) /a -> /b, #cmt', MountRule('mount', ('in', ['ext3', 'ext4']), ('=', ('ro', 'rbind')), '/a', '/b', False, False, False, ' #cmt')),
('mount fstype in (ext3, ext4) option in (ro, rbind) /a, #cmt', MountRule('mount', ('in', ['ext3', 'ext4']), ('in', ('ro', 'rbind')), '/a', MountRule.ALL, False, False, False, ' #cmt')),
('mount fstype=(ext3, ext4) option=(ro, rbind) /a -> /b, #cmt', MountRule('mount', ('=', ['ext3', 'ext4']), ('=', ('ro', 'rbind')), '/a', '/b', False, False, False, ' #cmt')),
('mount fstype=(ext3, ext4) options=(ro, sync) /a -> /b,', MountRule('mount', ('=', ['ext3', 'ext4']), ('=', ('ro', 'sync')), '/a', '/b', False, False, False, '' )),
('mount fstype=(ext3, ext4) options=(ro, sync) /a -> /b, #cmt', MountRule('mount', ('=', ['ext3', 'ext4']), ('=', ('ro', 'sync')), '/a', '/b', False, False, False, ' #cmt')),
('mount fstype=({ext3,ext4}) options in (ro, sync) /a -> /b,', MountRule('mount', ('=', ['{ext3,ext4}']), ('in', ('ro', 'sync')), '/a', '/b', False, False, False, '' )),
('mount fstype in (ext3, ext4) options=(ro, sync) /a -> /b, #cmt', MountRule('mount', ('in', ['ext3', 'ext4']), ('=', ('ro', 'sync')), '/a', '/b', False, False, False, ' #cmt')),
('mount fstype in (ext3, ext4) option in (ro, sync) /a, #cmt', MountRule('mount', ('in', ['ext3', 'ext4']), ('in', ('ro', 'sync')), '/a', MountRule.ALL, False, False, False, ' #cmt')),
('mount fstype=(ext3, ext4) option=(ro, sync) /a -> /b, #cmt', MountRule('mount', ('=', ['ext3', 'ext4']), ('=', ('ro', 'sync')), '/a', '/b', False, False, False, ' #cmt')),
('mount options=(rw, rbind) {,/usr}/lib{,32,64,x32}/modules/ -> /tmp/snap.rootfs_*{,/usr}/lib/modules/,',
MountRule('mount', MountRule.ALL, ('=', ('rw', 'rbind')), '{,/usr}/lib{,32,64,x32}/modules/',
'/tmp/snap.rootfs_*{,/usr}/lib/modules/',
@ -68,6 +68,17 @@ class MountTestParse(AATest):
expected.raw_rule = rawrule.strip()
self.assertTrue(obj.is_equal(expected, True))
def test_valid_mount_changing_propagation(self):
# Rules changing propagation type can either specify a source or a dest (these are equivalent for apparmor_parser in this specific case) but not both.
MountRule('mount', MountRule.ALL, ('=', ('runbindable')), '/foo', MountRule.ALL)
MountRule('mount', MountRule.ALL, ('=', ('runbindable')), MountRule.ALL, '/foo')
def test_valid_bind_mount(self):
# Fstype must remain empty in bind rules
MountRule('mount', MountRule.ALL, ('=', ('bind')), '/foo', MountRule.ALL)
MountRule('mount', MountRule.ALL, ('=', ('bind')), MountRule.ALL, '/bar')
MountRule('mount', MountRule.ALL, ('=', ('bind')), '/foo', '/bar')
class MountTestParseInvalid(AATest):
tests = (
@ -143,6 +154,20 @@ class MountTestParseInvalid(AATest):
with self.assertRaises(AppArmorException):
MountRule('remount', MountRule.ALL, MountRule.ALL, '/foo', MountRule.ALL)
def test_invalid_mount_changing_propagation(self):
# Rules changing propagation type can either specify a source or a dest (these are equivalent for apparmor_parser in this specific case) but not both.
with self.assertRaises(AppArmorException):
MountRule('mount', MountRule.ALL, ('=', ('runbindable')), '/foo', '/bar')
# Rules changing propagation type cannot specify a fstype.
with self.assertRaises(AppArmorException):
MountRule('mount', ('=', ('ext4')), ('=', ('runbindable')), MountRule.ALL, '/foo')
def test_invalid_bind_mount(self):
# Bind mount rules cannot specify a fstype.
with self.assertRaises(AppArmorException):
MountRule('mount', ('=', ('ext4')), ('=', ('bind')), MountRule.ALL, '/foo')
class MountTestGlob(AATest):
def test_glob(self):

View file

@ -85,16 +85,6 @@ exception_not_raised = (
'mount/bad_1.sd',
'mount/bad_2.sd',
# not checked/detected: "make-*" mount opt and an invalid src
'mount/bad_opt_17.sd',
'mount/bad_opt_18.sd',
'mount/bad_opt_19.sd',
'mount/bad_opt_20.sd',
'mount/bad_opt_21.sd',
'mount/bad_opt_22.sd',
'mount/bad_opt_23.sd',
'mount/bad_opt_24.sd',
'profile/flags/flags_bad10.sd',
'profile/flags/flags_bad11.sd',
'profile/flags/flags_bad12.sd',
@ -324,19 +314,6 @@ unknown_line = (
'bare_include_tests/ok_85.sd',
'bare_include_tests/ok_86.sd',
# Mount with flags in {remount, [r]unbindable, [r]shared, [r]private, [r]slave} does not support a source
'mount/ok_opt_68.sd',
'mount/ok_opt_69.sd',
'mount/ok_opt_70.sd',
'mount/ok_opt_71.sd',
'mount/ok_opt_72.sd',
'mount/ok_opt_73.sd',
'mount/ok_opt_74.sd',
'mount/ok_opt_75.sd',
# options=slave with /** src (first rule in the test causes exception)
'mount/ok_opt_84.sd',
# According to spec mount should be in the form fstype=... options=... and NOT in the form options=... fstype=...
'mount/ok_opt_combo_3.sd',
'mount/ok_opt_combo_2.sd',