Check that dest is valid for decompression (#3555)

* add check for valid dest buffer and fuzz on random dest ptr when malloc 0

* add uptrval to linux-kernel

* remove bin files

* get rid of uptrval

* restrict max pointer value check to platforms where sizeof(size_t) == sizeof(void*)

tests/fuzz/block_decompress.c

@@ -13,6 +13,7 @@
  * decompression function to ensure the decompressor never crashes.
  */
 
+#include "fuzz_data_producer.h"
 #define ZSTD_STATIC_LINKING_ONLY
 
 #include <stddef.h>
@@ -28,11 +29,12 @@ static size_t bufSize = 0;
 int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
 {
     size_t const neededBufSize = ZSTD_BLOCKSIZE_MAX;
+    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
 
     /* Allocate all buffers and contexts if not already allocated */
     if (neededBufSize > bufSize) {
         free(rBuf);
-        rBuf = FUZZ_malloc(neededBufSize);
+        rBuf = FUZZ_malloc_rand(neededBufSize, producer);
         bufSize = neededBufSize;
     }
     if (!dctx) {
@@ -42,6 +44,8 @@ int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
     ZSTD_decompressBegin(dctx);
     ZSTD_decompressBlock(dctx, rBuf, neededBufSize, src, size);
 
+    FUZZ_dataProducer_free(producer);
+
 #ifndef STATEFUL_FUZZING
     ZSTD_freeDCtx(dctx); dctx = NULL;
 #endif