Fix fuzzing detected failure

If both :authority and host appear in client initial headers, we either
leak (in opt builds) or crash (in dbg).

src/core/lib/transport/metadata_batch.c

@@ -258,16 +258,22 @@ grpc_error *grpc_metadata_batch_substitute(grpc_exec_ctx *exec_ctx,
                                            grpc_metadata_batch *batch,
                                            grpc_linked_mdelem *storage,
                                            grpc_mdelem new) {
+  assert_valid_callouts(exec_ctx, batch);
   grpc_error *error = GRPC_ERROR_NONE;
   grpc_mdelem old = storage->md;
   if (!grpc_slice_eq(GRPC_MDKEY(new), GRPC_MDKEY(old))) {
     maybe_unlink_callout(batch, storage);
     storage->md = new;
     error = maybe_link_callout(batch, storage);
+    if (error != GRPC_ERROR_NONE) {
+      unlink_storage(&batch->list, storage);
+      GRPC_MDELEM_UNREF(exec_ctx, storage->md);
+    }
   } else {
     storage->md = new;
   }
   GRPC_MDELEM_UNREF(exec_ctx, old);
+  assert_valid_callouts(exec_ctx, batch);
   return error;
 }
 

tools/run_tests/generated/tests.json

@@ -126451,6 +126451,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/0c129f78eacfb0d0d3c89dd4e578724096a3cea0"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/0c413d2b361b2221585026d42f3046ff4135d2ff"
@@ -128277,6 +128299,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/3b55d09b98e3982d6f80913a792463c3974766db"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/3ca5da2f.bin"
@@ -128607,6 +128651,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/416160124b3b64fc9355f24dd789b3d1fd097b8b"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/418f392319c44d06a018ce4c62569d527829177a"
@@ -131423,6 +131489,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/92f1df2266f34a097e96dd22188d8633832d37b1"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/93beeba2.bin"
@@ -131907,6 +131995,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/a40c3ba87b4206142b134f67485859b7c9b7c75c"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/a5348197.bin"
@@ -133491,6 +133601,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/crash-73923add5066617ae08f187b79d2639b4fd96138"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/crash-7af5da2a8da23d197d9336e32da72c9ff64c15b3"
@@ -134855,6 +134987,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/fcb1dea251d1ce74e30351f13a3f71e3debec3d2"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/fd14bea45ecaf13af0053900edb2f17b71a0bf09"
@@ -135031,6 +135185,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/fe740f8c4ffd07f79456c8cee24ef556ee348f55"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/ff227015.bin"
@@ -135119,6 +135295,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-03c6f209b2f144734c83d81ed452839d9e244fe9"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-082763e16153cb6b8f3f5308cd060e822f475e5a"
@@ -135185,6 +135383,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-129ecb5e7b80616f36791e3580844e520f2ba7d3"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-13501419f349b7855d2e94060bd08b28923d1f37"
@@ -135317,6 +135537,50 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-30408c9d13f29804168fc62a0818cc894c6375ae"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-33d8bf197de7131be78244e10fbb0da5055cf266"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-350b5da741597222c98fe86768432507850317f5"
@@ -135449,6 +135713,50 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-51cdbfa3e97a46ceefde405e6ab087a109c26907"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-523cb1bca5ad56690c618b4ceac7fceca1113b9d"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-58f116dfba8d428a01ca596174fca63f4ac523f0"
@@ -135845,6 +136153,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-a877fe99fd0e92721d162bc252bf72a4f67ba1ea"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-aa23c18f6badd88a7bec65e8b04f7801ba624ec6"
@@ -135977,6 +136307,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-bd9d24f5c7c915174b6ca9d1a3573e16e0edee12"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-bda43d420a3e5d5228a5f5130207a1f11fc1c81f"
@@ -136175,6 +136527,28 @@
     ], 
     "uses_polling": false
   }, 
+  {
+    "args": [
+      "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-f3c688876395bf7a529f29f7b91532726cf5cbce"
+    ], 
+    "ci_platforms": [
+      "linux"
+    ], 
+    "cpu_cost": 0.1, 
+    "exclude_configs": [
+      "tsan"
+    ], 
+    "exclude_iomgrs": [
+      "uv"
+    ], 
+    "flaky": false, 
+    "language": "c", 
+    "name": "server_fuzzer_one_entry", 
+    "platforms": [
+      "linux"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [
       "test/core/end2end/fuzzers/server_fuzzer_corpus/slow-unit-f412afea6b01aa53da919a41a65ffbf9885f2d65"