Disallow watch and watch_reads on apk_data_file for apps am: f9a774f1ae

Original change: https://googleplex-android-review.googlesource.com/c/platform/system/sepolicy/+/22283654

Change-Id: Id80c1e04d7aabee35cb92713a9435b2951cd24b5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

prebuilts/api/34.0/private/app.te

@@ -427,13 +427,6 @@ allow appdomain shared_relro_file:file r_file_perms;
 # Allow apps to read/execute installed binaries
 allow appdomain apk_data_file:dir { open getattr read search ioctl lock };
 allow appdomain apk_data_file:file { getattr open read ioctl lock map x_file_perms };
-# Allow watch & watch_reads for now, but audit to see if they're actually used.
-allow appdomain apk_data_file:dir { watch watch_reads };
-allow appdomain apk_data_file:file { watch watch_reads };
-userdebug_or_eng(`
-  auditallow appdomain apk_data_file:dir { watch watch_reads };
-  auditallow appdomain apk_data_file:file { watch watch_reads };
-')
 
 # /data/resource-cache
 allow appdomain resourcecache_data_file:file r_file_perms;
@@ -535,3 +528,23 @@ neverallow {
     appdomain
     -device_as_webcam
 } video_device:chr_file { read write };
+
+# Prevent calling inotify on APKs. This can be used as a side channel
+# to observer app launches, so it must be disallowed. b/231587164
+# Gate by targetSdkVersion to avoid breaking existing apps.
+neverallow {
+  appdomain
+  -untrusted_app_25
+  -untrusted_app_27
+  -untrusted_app_29
+  -untrusted_app_30
+  -untrusted_app_32
+} apk_data_file:dir { watch watch_reads };
+neverallow {
+  appdomain
+  -untrusted_app_25
+  -untrusted_app_27
+  -untrusted_app_29
+  -untrusted_app_30
+  -untrusted_app_32
+} apk_data_file:file { watch watch_reads };

prebuilts/api/34.0/private/untrusted_app_25.te

@@ -59,3 +59,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_25 mdnsd_socket:sock_file write;
   auditallow untrusted_app_25 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_25 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_25 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_25 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_25 apk_data_file:file { watch watch_reads };
+')

prebuilts/api/34.0/private/untrusted_app_27.te

@@ -47,3 +47,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_27 mdnsd_socket:sock_file write;
   auditallow untrusted_app_27 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_27 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_27 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_27 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_27 apk_data_file:file { watch watch_reads };
+')

prebuilts/api/34.0/private/untrusted_app_29.te

@@ -25,3 +25,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_29 mdnsd_socket:sock_file write;
   auditallow untrusted_app_29 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_29 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_29 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_29 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_29 apk_data_file:file { watch watch_reads };
+')

prebuilts/api/34.0/private/untrusted_app_30.te

@@ -27,3 +27,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_30 mdnsd_socket:sock_file write;
   auditallow untrusted_app_30 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_30 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_30 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_30 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_30 apk_data_file:file { watch watch_reads };
+')

prebuilts/api/34.0/private/untrusted_app_32.te

@@ -28,3 +28,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_32 mdnsd_socket:sock_file write;
   auditallow untrusted_app_32 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_32 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_32 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_32 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_32 apk_data_file:file { watch watch_reads };
+')

prebuilts/api/34.0/public/shell.te

@@ -63,8 +63,6 @@ allow shell toolbox_exec:file rx_file_perms;
 allow shell shell_exec:file rx_file_perms;
 allow shell zygote_exec:file rx_file_perms;
 
-r_dir_file(shell, apk_data_file)
-
 userdebug_or_eng(`
   # "systrace --boot" support - allow boottrace service to run
   allow shell boottrace_data_file:dir rw_dir_perms;

private/app.te

@@ -427,13 +427,6 @@ allow appdomain shared_relro_file:file r_file_perms;
 # Allow apps to read/execute installed binaries
 allow appdomain apk_data_file:dir { open getattr read search ioctl lock };
 allow appdomain apk_data_file:file { getattr open read ioctl lock map x_file_perms };
-# Allow watch & watch_reads for now, but audit to see if they're actually used.
-allow appdomain apk_data_file:dir { watch watch_reads };
-allow appdomain apk_data_file:file { watch watch_reads };
-userdebug_or_eng(`
-  auditallow appdomain apk_data_file:dir { watch watch_reads };
-  auditallow appdomain apk_data_file:file { watch watch_reads };
-')
 
 # /data/resource-cache
 allow appdomain resourcecache_data_file:file r_file_perms;
@@ -535,3 +528,23 @@ neverallow {
     appdomain
     -device_as_webcam
 } video_device:chr_file { read write };
+
+# Prevent calling inotify on APKs. This can be used as a side channel
+# to observer app launches, so it must be disallowed. b/231587164
+# Gate by targetSdkVersion to avoid breaking existing apps.
+neverallow {
+  appdomain
+  -untrusted_app_25
+  -untrusted_app_27
+  -untrusted_app_29
+  -untrusted_app_30
+  -untrusted_app_32
+} apk_data_file:dir { watch watch_reads };
+neverallow {
+  appdomain
+  -untrusted_app_25
+  -untrusted_app_27
+  -untrusted_app_29
+  -untrusted_app_30
+  -untrusted_app_32
+} apk_data_file:file { watch watch_reads };

private/untrusted_app_25.te

@@ -59,3 +59,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_25 mdnsd_socket:sock_file write;
   auditallow untrusted_app_25 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_25 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_25 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_25 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_25 apk_data_file:file { watch watch_reads };
+')

private/untrusted_app_27.te

@@ -47,3 +47,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_27 mdnsd_socket:sock_file write;
   auditallow untrusted_app_27 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_27 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_27 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_27 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_27 apk_data_file:file { watch watch_reads };
+')

private/untrusted_app_29.te

@@ -25,3 +25,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_29 mdnsd_socket:sock_file write;
   auditallow untrusted_app_29 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_29 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_29 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_29 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_29 apk_data_file:file { watch watch_reads };
+')

private/untrusted_app_30.te

@@ -27,3 +27,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_30 mdnsd_socket:sock_file write;
   auditallow untrusted_app_30 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_30 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_30 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_30 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_30 apk_data_file:file { watch watch_reads };
+')

private/untrusted_app_32.te

@@ -28,3 +28,12 @@ userdebug_or_eng(`
   auditallow untrusted_app_32 mdnsd_socket:sock_file write;
   auditallow untrusted_app_32 mdnsd:unix_stream_socket connectto;
 ')
+
+# Allow calling inotify on APKs for backwards compatibility. This is disallowed
+# for targetSdkVersion>=34 to remove a sidechannel.
+allow untrusted_app_32 apk_data_file:dir { watch watch_reads };
+allow untrusted_app_32 apk_data_file:file { watch watch_reads };
+userdebug_or_eng(`
+  auditallow untrusted_app_32 apk_data_file:dir { watch watch_reads };
+  auditallow untrusted_app_32 apk_data_file:file { watch watch_reads };
+')

public/shell.te

@@ -63,8 +63,6 @@ allow shell toolbox_exec:file rx_file_perms;
 allow shell shell_exec:file rx_file_perms;
 allow shell zygote_exec:file rx_file_perms;
 
-r_dir_file(shell, apk_data_file)
-
 userdebug_or_eng(`
   # "systrace --boot" support - allow boottrace service to run
   allow shell boottrace_data_file:dir rw_dir_perms;