commit 1f4bba0448563b7d1fe4d86c230556ebf8d3805b Author: Maxime Bélair <maxime.belair@canonical.com> Date: Mon May 20 11:09:04 2024 +0200 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 60acc4a4053ddb3718b9a2f5ceb1ef02fea3a226) Signed-off-by: Maxime Bélair <maxime.belair@canonical.com> diff --git a/utils/apparmor/rule/mount.py b/utils/apparmor/rule/mount.py index abfa2b75e..b2d73a27b 100644 --- a/utils/apparmor/rule/mount.py +++ b/utils/apparmor/rule/mount.py @@ -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 diff --git a/utils/test/test-mount.py b/utils/test/test-mount.py index 7f88ff7db..cb1a89630 100644 --- a/utils/test/test-mount.py +++ b/utils/test/test-mount.py @@ -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): diff --git a/utils/test/test-parser-simple-tests.py b/utils/test/test-parser-simple-tests.py index 451af7d22..60a738aed 100644 --- a/utils/test/test-parser-simple-tests.py +++ b/utils/test/test-parser-simple-tests.py @@ -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',