Nick Kralevich | 748fdef | 2013-07-12 16:33:29 -0700 | [diff] [blame] | 1 | ### |
| 2 | ### Untrusted apps. |
| 3 | ### |
Stephen Smalley | d823f83 | 2014-02-21 13:26:20 -0500 | [diff] [blame] | 4 | ### This file defines the rules for untrusted apps. |
| 5 | ### Apps are labeled based on mac_permissions.xml (maps signer and |
| 6 | ### optionally package name to seinfo value) and seapp_contexts (maps UID |
| 7 | ### and optionally seinfo value to domain for process and type for data |
| 8 | ### directory). The untrusted_app domain is the default assignment in |
| 9 | ### seapp_contexts for any app with UID between APP_AID (10000) |
| 10 | ### and AID_ISOLATED_START (99000) if the app has no specific seinfo |
| 11 | ### value as determined from mac_permissions.xml. In current AOSP, this |
| 12 | ### domain is assigned to all non-system apps as well as to any system apps |
Stephen Smalley | 9ba844f | 2014-04-04 09:09:25 -0400 | [diff] [blame] | 13 | ### that are not signed by the platform key. To move |
Stephen Smalley | d823f83 | 2014-02-21 13:26:20 -0500 | [diff] [blame] | 14 | ### a system app into a specific domain, add a signer entry for it to |
| 15 | ### mac_permissions.xml and assign it one of the pre-existing seinfo values |
| 16 | ### or define and use a new seinfo value in both mac_permissions.xml and |
| 17 | ### seapp_contexts. |
Nick Kralevich | 748fdef | 2013-07-12 16:33:29 -0700 | [diff] [blame] | 18 | ### |
| 19 | ### untrusted_app includes all the appdomain rules, plus the |
| 20 | ### additional following rules: |
| 21 | ### |
| 22 | |
| 23 | type untrusted_app, domain; |
Nick Kralevich | 748fdef | 2013-07-12 16:33:29 -0700 | [diff] [blame] | 24 | app_domain(untrusted_app) |
| 25 | net_domain(untrusted_app) |
| 26 | bluetooth_domain(untrusted_app) |
Nick Kralevich | 6634a10 | 2013-07-12 18:45:56 -0700 | [diff] [blame] | 27 | |
Stephen Smalley | 6531712 | 2013-12-11 09:08:09 -0500 | [diff] [blame] | 28 | # Some apps ship with shared libraries and binaries that they write out |
| 29 | # to their sandbox directory and then execute. |
Nick Kralevich | 78706f9 | 2014-06-02 14:49:10 -0700 | [diff] [blame] | 30 | allow untrusted_app app_data_file:file { rx_file_perms execmod }; |
Stephen Smalley | 6531712 | 2013-12-11 09:08:09 -0500 | [diff] [blame] | 31 | |
Nick Kralevich | 6634a10 | 2013-07-12 18:45:56 -0700 | [diff] [blame] | 32 | allow untrusted_app tun_device:chr_file rw_file_perms; |
| 33 | |
Nick Kralevich | 6634a10 | 2013-07-12 18:45:56 -0700 | [diff] [blame] | 34 | # ASEC |
Nick Kralevich | 6634a10 | 2013-07-12 18:45:56 -0700 | [diff] [blame] | 35 | allow untrusted_app asec_apk_file:file r_file_perms; |
Robert Craig | 48b1883 | 2014-02-04 11:36:41 -0500 | [diff] [blame] | 36 | # Execute libs in asec containers. |
Nick Kralevich | 78706f9 | 2014-06-02 14:49:10 -0700 | [diff] [blame] | 37 | allow untrusted_app asec_public_file:file { execute execmod }; |
Nick Kralevich | 6634a10 | 2013-07-12 18:45:56 -0700 | [diff] [blame] | 38 | |
Nick Kralevich | 6634a10 | 2013-07-12 18:45:56 -0700 | [diff] [blame] | 39 | # Allow the allocation and use of ptys |
| 40 | # Used by: https://play.google.com/store/apps/details?id=jackpal.androidterm |
Stephen Smalley | 2dc4acf | 2013-09-27 09:44:32 -0400 | [diff] [blame] | 41 | create_pty(untrusted_app) |
Nick Kralevich | 8a2ebe3 | 2013-07-15 15:48:34 -0700 | [diff] [blame] | 42 | |
| 43 | # Used by Finsky / Android "Verify Apps" functionality when |
| 44 | # running "adb install foo.apk". |
| 45 | # TODO: Long term, we don't want apps probing into shell data files. |
| 46 | # Figure out a way to remove these rules. |
Nick Kralevich | 2f40a17 | 2013-09-04 16:12:33 -0700 | [diff] [blame] | 47 | allow untrusted_app shell_data_file:file r_file_perms; |
Nick Kralevich | 8a2ebe3 | 2013-07-15 15:48:34 -0700 | [diff] [blame] | 48 | allow untrusted_app shell_data_file:dir r_dir_perms; |
Stephen Smalley | 9ba844f | 2014-04-04 09:09:25 -0400 | [diff] [blame] | 49 | |
Nick Kralevich | 1aafc4c | 2014-12-03 16:26:26 -0800 | [diff] [blame] | 50 | # b/18504118: Allow reads from /data/anr/traces.txt |
| 51 | # TODO: We shouldn't be allowing all untrusted_apps to read |
| 52 | # this file. This is only needed for the GMS feedback agent. |
| 53 | # See also b/18340553. GMS runs as untrusted_app, and |
| 54 | # it's too late to change the domain it runs in. |
| 55 | # This line needs to be deleted. |
| 56 | allow untrusted_app anr_data_file:file r_file_perms; |
| 57 | |
Nick Kralevich | 8be3e77 | 2015-03-05 15:40:04 -0800 | [diff] [blame] | 58 | # Read and write system app data files passed over Binder. |
| 59 | # Motivating case was /data/data/com.android.settings/cache/*.jpg for |
| 60 | # cropping or taking user photos. |
| 61 | allow untrusted_app system_app_data_file:file { read write getattr }; |
| 62 | |
Stephen Smalley | 9ba844f | 2014-04-04 09:09:25 -0400 | [diff] [blame] | 63 | # |
| 64 | # Rules migrated from old app domains coalesced into untrusted_app. |
| 65 | # This includes what used to be media_app, shared_app, and release_app. |
| 66 | # |
| 67 | |
| 68 | # Access /dev/mtp_usb. |
| 69 | allow untrusted_app mtp_device:chr_file rw_file_perms; |
| 70 | |
| 71 | # Access to /data/media. |
| 72 | allow untrusted_app media_rw_data_file:dir create_dir_perms; |
| 73 | allow untrusted_app media_rw_data_file:file create_file_perms; |
| 74 | |
Jeff Sharkey | 6e1f405 | 2015-05-19 13:52:51 -0700 | [diff] [blame] | 75 | # Traverse into /mnt/media_rw for bypassing FUSE daemon |
| 76 | # TODO: narrow this to just MediaProvider |
| 77 | allow untrusted_app mnt_media_rw_file:dir search; |
| 78 | |
Stephen Smalley | 9ba844f | 2014-04-04 09:09:25 -0400 | [diff] [blame] | 79 | # Write to /cache. |
| 80 | allow untrusted_app cache_file:dir create_dir_perms; |
| 81 | allow untrusted_app cache_file:file create_file_perms; |
Nick Kralevich | 4bdd13e | 2014-05-13 14:45:00 -0700 | [diff] [blame] | 82 | |
dcashman | 0b764ae | 2015-09-08 18:22:12 -0700 | [diff] [blame] | 83 | # allow cts to query all services |
| 84 | allow untrusted_app servicemanager:service_manager list; |
| 85 | |
dcashman | cd82557 | 2014-12-11 16:01:27 -0800 | [diff] [blame] | 86 | allow untrusted_app drmserver_service:service_manager find; |
Ruchi Kandoi | ac8b575 | 2015-10-19 13:00:46 -0700 | [diff] [blame] | 87 | allow untrusted_app healthd_service:service_manager find; |
dcashman | cd82557 | 2014-12-11 16:01:27 -0800 | [diff] [blame] | 88 | allow untrusted_app mediaserver_service:service_manager find; |
| 89 | allow untrusted_app nfc_service:service_manager find; |
| 90 | allow untrusted_app radio_service:service_manager find; |
| 91 | allow untrusted_app surfaceflinger_service:service_manager find; |
dcashman | d12993f | 2015-04-02 16:50:08 -0700 | [diff] [blame] | 92 | allow untrusted_app app_api_service:service_manager find; |
| 93 | |
| 94 | # TODO: remove this once priv-apps are no longer running in untrusted_app |
| 95 | allow untrusted_app system_api_service:service_manager find; |
dcashman | 4a89cdf | 2014-12-16 15:45:26 -0800 | [diff] [blame] | 96 | |
dcashman | 03a6f64 | 2015-04-08 13:04:59 -0700 | [diff] [blame] | 97 | # TODO: remove and replace with specific package that accesses this |
| 98 | allow untrusted_app persistent_data_block_service:service_manager find; |
| 99 | |
Stephen Smalley | b8caf7f | 2015-03-13 16:42:42 -0400 | [diff] [blame] | 100 | # Allow verifier to access staged apks. |
| 101 | allow untrusted_app { apk_tmp_file apk_private_tmp_file }:dir r_dir_perms; |
| 102 | allow untrusted_app { apk_tmp_file apk_private_tmp_file }:file r_file_perms; |
| 103 | |
Jeff Vander Stoep | de9b530 | 2015-06-05 15:28:55 -0700 | [diff] [blame] | 104 | # only allow unprivileged socket ioctl commands |
Jeff Vander Stoep | 90ccbcf | 2016-04-26 11:29:14 -0700 | [diff] [blame] | 105 | allow untrusted_app domain:{ rawip_socket tcp_socket udp_socket } unpriv_sock_ioctls; |
Jeff Vander Stoep | 86f30cb | 2015-05-05 15:43:15 -0700 | [diff] [blame] | 106 | |
Dehao Chen | 34a468f | 2015-05-05 15:11:44 -0700 | [diff] [blame] | 107 | # Allow GMS core to access perfprofd output, which is stored |
| 108 | # in /data/misc/perfprofd/. GMS core will need to list all |
| 109 | # data stored in that directory to process them one by one. |
| 110 | userdebug_or_eng(` |
| 111 | allow untrusted_app perfprofd_data_file:file r_file_perms; |
| 112 | allow untrusted_app perfprofd_data_file:dir r_dir_perms; |
| 113 | ') |
Nick Kralevich | f6d12c6 | 2015-05-13 16:06:34 -0700 | [diff] [blame] | 114 | |
| 115 | # Programs routinely attempt to scan through /system, looking |
| 116 | # for files. Suppress the denials when they occur. |
| 117 | dontaudit untrusted_app exec_type:file getattr; |
| 118 | |
Nick Kralevich | 4bdd13e | 2014-05-13 14:45:00 -0700 | [diff] [blame] | 119 | ### |
| 120 | ### neverallow rules |
| 121 | ### |
| 122 | |
Nick Kralevich | 642b804 | 2014-09-21 23:35:24 -0700 | [diff] [blame] | 123 | # Receive or send uevent messages. |
Nick Kralevich | d31936f | 2015-01-28 17:46:30 -0800 | [diff] [blame] | 124 | neverallow untrusted_app domain:netlink_kobject_uevent_socket *; |
| 125 | |
| 126 | # Receive or send generic netlink messages |
| 127 | neverallow untrusted_app domain:netlink_socket *; |
Nick Kralevich | 642b804 | 2014-09-21 23:35:24 -0700 | [diff] [blame] | 128 | |
Nick Kralevich | 4bdd13e | 2014-05-13 14:45:00 -0700 | [diff] [blame] | 129 | # Too much leaky information in debugfs. It's a security |
| 130 | # best practice to ensure these files aren't readable. |
| 131 | neverallow untrusted_app debugfs:file read; |
Riley Spahn | 76206ab | 2014-07-07 09:27:53 -0700 | [diff] [blame] | 132 | |
| 133 | # Do not allow untrusted apps to register services. |
| 134 | # Only trusted components of Android should be registering |
| 135 | # services. |
| 136 | neverallow untrusted_app service_manager_type:service_manager add; |
Nick Kralevich | 99d86c7 | 2014-07-09 18:58:04 -0700 | [diff] [blame] | 137 | |
Nick Kralevich | f583566 | 2014-07-09 19:03:08 -0700 | [diff] [blame] | 138 | # Do not allow untrusted_apps to connect to the property service |
Nick Kralevich | 99d86c7 | 2014-07-09 18:58:04 -0700 | [diff] [blame] | 139 | # or set properties. b/10243159 |
| 140 | neverallow untrusted_app property_socket:sock_file write; |
| 141 | neverallow untrusted_app init:unix_stream_socket connectto; |
| 142 | neverallow untrusted_app property_type:property_service set; |
Stephen Smalley | eaece93 | 2015-03-13 16:54:48 -0400 | [diff] [blame] | 143 | |
| 144 | # Do not allow untrusted_app to be assigned mlstrustedsubject. |
| 145 | # This would undermine the per-user isolation model being |
| 146 | # enforced via levelFrom=user in seapp_contexts and the mls |
| 147 | # constraints. As there is no direct way to specify a neverallow |
| 148 | # on attribute assignment, this relies on the fact that fork |
| 149 | # permission only makes sense within a domain (hence should |
| 150 | # never be granted to any other domain within mlstrustedsubject) |
| 151 | # and untrusted_app is allowed fork permission to itself. |
| 152 | neverallow untrusted_app mlstrustedsubject:process fork; |
Nick Kralevich | 85ce2c7 | 2015-03-26 18:18:03 -0700 | [diff] [blame] | 153 | |
| 154 | # Do not allow untrusted_app to hard link to any files. |
| 155 | # In particular, if untrusted_app links to other app data |
| 156 | # files, installd will not be able to guarantee the deletion |
| 157 | # of the linked to file. Hard links also contribute to security |
| 158 | # bugs, so we want to ensure untrusted_app never has this |
| 159 | # capability. |
| 160 | neverallow untrusted_app file_type:file link; |