Fix reading of bad relocation type (#1672)

Fixes: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=30792
WebAssembly · May 28, 2021 · e808dfe · e808dfe
1 parent 63c3509
commit e808dfe
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Showing 2 changed files with 32 additions and 2 deletions.
diff --git a/src/common.h b/src/common.h
@@ -420,7 +420,7 @@ void InitStdio();
 extern const char* g_kind_name[];
 
 static WABT_INLINE const char* GetKindName(ExternalKind kind) {
-  return static_cast<int>(kind) < kExternalKindCount
+  return static_cast<size_t>(kind) < kExternalKindCount
     ? g_kind_name[static_cast<size_t>(kind)]
     : "<error_kind>";
 }
@@ -430,7 +430,7 @@ static WABT_INLINE const char* GetKindName(ExternalKind kind) {
 extern const char* g_reloc_type_name[];
 
 static WABT_INLINE const char* GetRelocTypeName(RelocType reloc) {
-  return static_cast<int>(reloc) < kRelocTypeCount
+  return static_cast<size_t>(reloc) < kRelocTypeCount
     ? g_reloc_type_name[static_cast<size_t>(reloc)]
     : "<error_reloc_type>";
 }

diff --git a/test/binary/bad-reloc-type.txt b/test/binary/bad-reloc-type.txt
@@ -0,0 +1,30 @@
+;;; TOOL: run-objdump-gen-wasm
+;;; ARGS: -x
+magic
+version
+section(TYPE) { count[1] function params[0] results[0] }
+section("reloc.BAD") {
+  reloc_section[0]
+  reloc_count[1]
+  reloc_type[leb_i32(0xffffffff)]
+  reloc_offset[0]
+  reloc_index[0]
+}
+(;; STDERR ;;;
+0000023: warning: unknown reloc type: <error_reloc_type>
+;;; STDERR ;;)
+(;; STDOUT ;;;
+
+bad-reloc-type.wasm:	file format wasm 0x1
+
+Section Details:
+
+Type[1]:
+ - type[0] () -> nil
+Custom:
+ - name: "reloc.BAD"
+  - relocations for section: 0 (Type) [1]
+
+Code Disassembly:
+
+;;; STDOUT ;;)