Merge pull request #2534 from foxeng/fix-seek-descriptor-check

Fix seek table descriptor check when loading

.github/workflows/generic-dev.yml

@@ -62,7 +62,7 @@ jobs:
     # zbufftest-dll : test that a user program can link to multi-threaded libzstd without specifying -pthread
 
   gcc-8-asan-ubsan-testzstd:
-    runs-on: ubuntu-16.04 # fails on 18.04
+    runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
     - name: gcc-8 + ASan + UBSan + Test Zstd

contrib/seekable_format/tests/seekable_tests.c

@@ -103,7 +103,7 @@ int main(int argc, const char** argv)
             '\x00',
             '\x00',
             '\x00',
-            ';',
+            (uint8_t)('\x03'),
             (uint8_t)('\xb1'),
             (uint8_t)('\xea'),
             (uint8_t)('\x92'),

contrib/seekable_format/zstdseek_decompress.c

@@ -332,7 +332,7 @@ static size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable* zs)
         checksumFlag = sfd >> 7;
 
         /* check reserved bits */
-        if ((checksumFlag >> 2) & 0x1f) {
+        if ((sfd >> 2) & 0x1f) {
             return ERROR(corruption_detected);
     }   }