commit 23f9f51fcdfe85d1c5cdafedd08e0bf958094520
author Hridya Valsaraju <hridya@google.com> Tue May 04 22:01:51 2021 -0700
committer Hridya Valsaraju <hridya@google.com> Tue May 04 22:06:46 2021 -0700
tree 996494dac4d4af27628b263f2f31caa64d7b8e6c
parent 6c03124c3c76df773240c6b7d0f2c2f0dc8a3ef5

Revert "Revert "Add neverallows for debugfs access""

This reverts commit e95e0ec0a5f2f6fdf362d14b7960850a05e790b5.

Now that b/186727553 is fixed, it should be safe to revert this revert.

Test: build
Bug: 184381659
Change-Id: Ibea3882296db880f5cafe4f9efa36d79a183c8a1

private/coredomain.te

diff --git a/private/coredomain.te b/private/coredomain.te
index 9fe82d3..b7f4f5d 100644
--- a/private/coredomain.te
+++ b/private/coredomain.te
@@ -153,9 +153,11 @@
   # debugfs
   neverallow {
     coredomain
-    -dumpstate
-    -init
-    -system_server
+    no_debugfs_restriction(`
+      -dumpstate
+      -init
+      -system_server
+    ')
   } debugfs:file no_rw_file_perms;
 
   # tracefs

private/domain.te

diff --git a/private/domain.te b/private/domain.te
index c7a3495..4b8bb2a 100644
--- a/private/domain.te
+++ b/private/domain.te
@@ -521,3 +521,18 @@
   -traced_probes
   -traced_perf
 } proc_kallsyms:file { open read };
+
+# debugfs_kcov type is not included in this neverallow statement since the KCOV
+# tool uses it for kernel fuzzing.
+enforce_debugfs_restriction(`
+  neverallow {
+    domain
+    userdebug_or_eng(`
+      -init
+      -hal_dumpstate
+    ')
+  } { debugfs_type
+      userdebug_or_eng(`-debugfs_kcov')
+      -tracefs_type
+  }:file no_rw_file_perms;
+')

private/dumpstate.te

diff --git a/private/dumpstate.te b/private/dumpstate.te
index 13e3b4c..f418fa3 100644
--- a/private/dumpstate.te
+++ b/private/dumpstate.te
@@ -54,7 +54,10 @@
 }:process signal;
 
 # For collecting bugreports.
-allow dumpstate debugfs_wakeup_sources:file r_file_perms;
+no_debugfs_restriction(`
+  allow dumpstate debugfs_wakeup_sources:file r_file_perms;
+')
+
 allow dumpstate dev_type:blk_file getattr;
 allow dumpstate webview_zygote:process signal;
 allow dumpstate sysfs_dmabuf_stats:file r_file_perms;

private/incidentd.te

diff --git a/private/incidentd.te b/private/incidentd.te
index a574eee..ef191a2 100644
--- a/private/incidentd.te
+++ b/private/incidentd.te
@@ -29,7 +29,9 @@
 allow incidentd proc_pagetypeinfo:file r_file_perms;
 
 # section id 2002, allow reading /d/wakeup_sources
-allow incidentd debugfs_wakeup_sources:file r_file_perms;
+no_debugfs_restriction(`
+  allow incidentd debugfs_wakeup_sources:file r_file_perms;
+')
 
 # section id 2003, allow executing top
 allow incidentd proc_meminfo:file { open read };

private/storaged.te

diff --git a/private/storaged.te b/private/storaged.te
index b7d4ae9..bb39e5b 100644
--- a/private/storaged.te
+++ b/private/storaged.te
@@ -18,10 +18,12 @@
 allow storaged storaged_data_file:dir rw_dir_perms;
 allow storaged storaged_data_file:file create_file_perms;
 
-userdebug_or_eng(`
-  # Read access to debugfs
-  allow storaged debugfs_mmc:dir search;
-  allow storaged debugfs_mmc:file r_file_perms;
+no_debugfs_restriction(`
+  userdebug_or_eng(`
+    # Read access to debugfs
+    allow storaged debugfs_mmc:dir search;
+    allow storaged debugfs_mmc:file r_file_perms;
+  ')
 ')
 
 # Needed to provide debug dump output via dumpsys pipes.

private/system_server.te

diff --git a/private/system_server.te b/private/system_server.te
index caf5208..08c4e40 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -184,7 +184,9 @@
 allow system_server stats_data_file:file unlink;
 
 # Read /sys/kernel/debug/wakeup_sources.
-allow system_server debugfs_wakeup_sources:file r_file_perms;
+no_debugfs_restriction(`
+  allow system_server debugfs_wakeup_sources:file r_file_perms;
+')
 
 # Read /sys/kernel/ion/*.
 allow system_server sysfs_ion:file r_file_perms;