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
(cherry picked from commit 18a6ada4aa136da4f50f03fff91d61d448ced195)

1 files changed, 9 insertions, 1 deletions

diff --git a/libs/androidfw/ResourceTypes.cpp b/libs/androidfw/ResourceTypes.cpp
index 109619bf84a..da3f5c6d0a9 100644
--- a/libs/androidfw/ResourceTypes.cpp
+++ b/libs/androidfw/ResourceTypes.cpp
@@ -6376,8 +6376,16 @@ 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);
                 }