commit 0fd25a6107fa8053abc0c72395f5d11c5fc85055
author Janis Danisevskis <jdanis@google.com> Tue Jan 04 19:53:37 2022 -0800
committer Janis Danisevskis <jdanis@google.com> Thu Jan 27 13:05:45 2022 -0800
tree ae34634ba46688233b0b6a0cb4439b59f9996a16
parent ff86de42e23446845eb837646c6516e5d12026cb

Keystore 2.0: Fix racy super key management.

The super key and user state management performs concurrent lookups and
cache updates that can put keystore2 in an inconsistent state which may
lead to loss of keys. It is unlikely that this data loss was trigered,
because system server does not call keystore2 in the way required to
cause problems.

Test: keystore2_tests and CTS tests for regression testing.
Bug: 213942761
Change-Id: Ieedb4806403d3aa7175c98f2dca26532ff609cea

keystore2/src/security_level.rs

diff --git a/keystore2/src/security_level.rs b/keystore2/src/security_level.rs
index 9334930..83f0bee 100644
--- a/keystore2/src/security_level.rs
+++ b/keystore2/src/security_level.rs
@@ -160,6 +160,8 @@
                     let mut db = db.borrow_mut();
 
                     let (key_blob, mut blob_metadata) = SUPER_KEY
+                        .read()
+                        .unwrap()
                         .handle_super_encryption_on_key_init(
                             &mut db,
                             &LEGACY_MIGRATOR,
@@ -303,6 +305,8 @@
             .context("In create_operation.")?;
 
         let km_blob = SUPER_KEY
+            .read()
+            .unwrap()
             .unwrap_key_if_required(&blob_metadata, km_blob)
             .context("In create_operation. Failed to handle super encryption.")?;
 
@@ -736,8 +740,11 @@
             .ok_or_else(error::Error::sys)
             .context("No km_blob after successfully loading key. This should never happen.")?;
 
-        let wrapping_key_blob =
-            SUPER_KEY.unwrap_key_if_required(&wrapping_blob_metadata, &wrapping_key_blob).context(
+        let wrapping_key_blob = SUPER_KEY
+            .read()
+            .unwrap()
+            .unwrap_key_if_required(&wrapping_blob_metadata, &wrapping_key_blob)
+            .context(
                 "In import_wrapped_key. Failed to handle super encryption for wrapping key.",
             )?;