Fix DynamicRefTable::load security bug

DynamicRefTables parsed from apks are missing bounds checks that prevent
buffer overflows. This changes verifies the bounds of the header before
attempting to preform operations on the chunk.

Bug: 79488511
Test: run cts -m CtsAppSecurityHostTestCases \
        -t android.appsecurity.cts.CorruptApkTests

Change-Id: I02c8ad957da244fce777ac68a482e4e8fa70f846
Merged-In: I02c8ad957da244fce777ac68a482e4e8fa70f846

1 files changed, 9 insertions, 1 deletions

diff --git a/libs/androidfw/ResourceTypes.cpp b/libs/androidfw/ResourceTypes.cpp
index 401c7b070188..2e77d8ca651d 100644
--- a/libs/androidfw/ResourceTypes.cpp
+++ b/libs/androidfw/ResourceTypes.cpp
@@ -6576,8 +6576,16 @@ status_t ResTable::parsePackage(const ResTable_package* const pkg,
             }
 
         } else if (ctype == RES_TABLE_LIBRARY_TYPE) {
+
             if (group->dynamicRefTable.entries().size() == 0) {
-                status_t err = group->dynamicRefTable.load((const ResTable_lib_header*) chunk);
+                const ResTable_lib_header* lib = (const ResTable_lib_header*) chunk;
+                status_t err = validate_chunk(&lib->header, sizeof(*lib),
+                                              endPos, "ResTable_lib_header");
+                if (err != NO_ERROR) {
+                    return (mError=err);
+                }
+
+                err = group->dynamicRefTable.load(lib);
                 if (err != NO_ERROR) {
                     return (mError=err);
                 }