diff --git a/src/compress.cpp b/src/compress.cpp
index a5ce6666..ee5e0d51 100644
--- a/src/compress.cpp
+++ b/src/compress.cpp
@@ -149,6 +149,9 @@ int upx_decompress         ( const upx_bytep src, upx_uint  src_len,
 {
     int r = UPX_E_ERROR;
 
+    assert(*dst_len > 0);
+    assert(src_len < *dst_len); // must be compressed
+
     if (result && result->method == 0)
         result = NULL;
 
@@ -188,6 +191,7 @@ int upx_test_overlap       ( const upx_bytep buf, upx_uint src_off,
     if (result && result->method == 0)
         result = NULL;
 
+    assert(*dst_len > 0);
     assert(src_len < *dst_len); // must be compressed
     unsigned overlap_overhead = src_off + src_len - *dst_len;
     assert((int)overlap_overhead > 0);
diff --git a/src/p_lx_elf.cpp b/src/p_lx_elf.cpp
index aed1b15e..6505ca78 100644
--- a/src/p_lx_elf.cpp
+++ b/src/p_lx_elf.cpp
@@ -319,23 +319,24 @@ PackLinuxElf32x86::buildLinuxLoader(
 
     unsigned char *const cprLoader = new unsigned char[sizeof(h) + h.sz_unc];
   if (0 < szfold) {
-    memset(cprLoader, 0, sizeof(h) + h.sz_unc);
     h.sz_cpr = h.sz_unc;  // amount that the compressor may use
     int r = upx_compress(uncLoader, h.sz_unc, sizeof(h) + cprLoader, &h.sz_cpr,
         NULL, ph.method, 10, NULL, NULL );
     if (r != UPX_E_OK || h.sz_cpr >= h.sz_unc)
         throwInternalError("loader compression failed");
+#if 1  //{
     if (M_LZMA==ph.method) {  // FIXME: debugging only
         ucl_uint tmp_len = h.sz_unc;  // LZMA uses this as EOF
-        unsigned char *tmp = new unsigned char[h.sz_unc];
-        memset(tmp, 0, h.sz_unc);
+        unsigned char *tmp = new unsigned char[tmp_len];
+        memset(tmp, 0, tmp_len);
         r = upx_decompress(sizeof(h) + cprLoader, h.sz_cpr, tmp, &tmp_len, h.b_method, NULL);
-        printf("%d %d: %d %d %d\n", h.b_method, r, h.sz_cpr, h.sz_unc, tmp_len);
+        printf("\n%d %d: %d %d %d\n", h.b_method, r, h.sz_cpr, h.sz_unc, tmp_len);
         for (unsigned j=0; j < h.sz_unc; ++j) if (tmp[j]!=uncLoader[j]) {
             printf("%d: %x %x\n", j, tmp[j], uncLoader[j]);
         }
         delete[] tmp;
     }
+#endif  //}
   }
     memcpy(cprLoader, &h, sizeof(h));