Check and restorecon cache/code_cache directories.

To speed up boot times, we recently relaxed SELinux restorecon logic
to only consider relabeling app storage when the top level SELinux
label changed.

However, if an app manually deletes either their cache or code_cache
directories, installd will helpfully recreate those directories at
the next boot, but they'll be stuck with incorrect SELinux labels
which an app can't fix.  (Our historically aggressive restorecons had
relabeled them, which is why we didn't observe until now.)

This change checks the labels of the cache/code_cache directories,
and runs a restorecon if needed, fixing the issue above.

Test: delete cache and verify recreated with correct label
Bug: 32504081
Change-Id: I0114ae4129223e5909b1075d56a9b1145ebc5ef4

diff --git a/cmds/installd/commands.cpp b/cmds/installd/commands.cpp
index 4ed8997..271c75b 100644 (file)
--- a/cmds/installd/commands.cpp
+++ b/cmds/installd/commands.cpp
@@ -104,7 +104,7 @@ static std::string create_primary_profile(const std::string& profile_dir) {
  * if the label of that top-level file actually changed.  This can save us
  * significant time by avoiding no-op traversals of large filesystem trees.
  */
-static int restorecon_app_data_lazy(const char* path, const char* seinfo, uid_t uid) {
+static int restorecon_app_data_lazy(const std::string& path, const char* seinfo, uid_t uid) {
     int res = 0;
     char* before = nullptr;
     char* after = nullptr;
@@ -112,15 +112,15 @@ static int restorecon_app_data_lazy(const char* path, const char* seinfo, uid_t
     // Note that SELINUX_ANDROID_RESTORECON_DATADATA flag is set by
     // libselinux. Not needed here.
 
-    if (lgetfilecon(path, &before) < 0) {
+    if (lgetfilecon(path.c_str(), &before) < 0) {
         PLOG(ERROR) << "Failed before getfilecon for " << path;
         goto fail;
     }
-    if (selinux_android_restorecon_pkgdir(path, seinfo, uid, 0) < 0) {
+    if (selinux_android_restorecon_pkgdir(path.c_str(), seinfo, uid, 0) < 0) {
         PLOG(ERROR) << "Failed top-level restorecon for " << path;
         goto fail;
     }
-    if (lgetfilecon(path, &after) < 0) {
+    if (lgetfilecon(path.c_str(), &after) < 0) {
         PLOG(ERROR) << "Failed after getfilecon for " << path;
         goto fail;
     }
@@ -130,7 +130,7 @@ static int restorecon_app_data_lazy(const char* path, const char* seinfo, uid_t
     if (strcmp(before, after)) {
         LOG(DEBUG) << "Detected label change from " << before << " to " << after << " at " << path
                 << "; running recursive restorecon";
-        if (selinux_android_restorecon_pkgdir(path, seinfo, uid,
+        if (selinux_android_restorecon_pkgdir(path.c_str(), seinfo, uid,
                 SELINUX_ANDROID_RESTORECON_RECURSE) < 0) {
             PLOG(ERROR) << "Failed recursive restorecon for " << path;
             goto fail;
@@ -146,6 +146,11 @@ done:
     return res;
 }
 
+static int restorecon_app_data_lazy(const std::string& parent, const char* name, const char* seinfo,
+        uid_t uid) {
+    return restorecon_app_data_lazy(StringPrintf("%s/%s", parent.c_str(), name), seinfo, uid);
+}
+
 static int prepare_app_dir(const std::string& path, mode_t target_mode, uid_t uid) {
     if (fs_prepare_dir_strict(path.c_str(), target_mode, uid, uid) != 0) {
         PLOG(ERROR) << "Failed to prepare " << path;
@@ -172,7 +177,9 @@ int create_app_data(const char *uuid, const char *pkgname, userid_t userid, int
         }
 
         // Consider restorecon over contents if label changed
-        if (restorecon_app_data_lazy(path.c_str(), seinfo, uid)) {
+        if (restorecon_app_data_lazy(path, seinfo, uid) ||
+                restorecon_app_data_lazy(path, "cache", seinfo, uid) ||
+                restorecon_app_data_lazy(path, "code_cache", seinfo, uid)) {
             return -1;
         }
 
@@ -191,7 +198,7 @@ int create_app_data(const char *uuid, const char *pkgname, userid_t userid, int
         }
 
         // Consider restorecon over contents if label changed
-        if (restorecon_app_data_lazy(path.c_str(), seinfo, uid)) {
+        if (restorecon_app_data_lazy(path, seinfo, uid)) {
             return -1;
         }