diff --git a/common/bstrlib/bstrlib.c b/common/bstrlib/bstrlib.c
index 5eaada2..e44e76d 100644
--- a/common/bstrlib/bstrlib.c
+++ b/common/bstrlib/bstrlib.c
@@ -2399,7 +2399,10 @@ int i, c, v;
 		v = (bl->qty - 1) * len;
 		if ((bl->qty > 512 || len > 127) &&
 		    v / len != bl->qty - 1) return NULL; /* Overflow */
-		if (v > INT_MAX - c) return NULL;	/* Overflow */
+		if (v > INT_MAX - c) {
+			bstr__free (b);
+			return NULL;	/* Overflow */
+		}
 		c += v;
 		p = b->data = (unsigned char *) bstr__alloc (c);
 		if (p == NULL) {
@@ -2542,6 +2545,7 @@ int bssplitstrcb (struct bStream * s, const_bstring splitStr,
 			}
 			buff->slen = 0;
 		}
+		bdestroy (buff);
 		return BSTR_OK;
 	} else {
 		for (;;) {
diff --git a/common/ffs.cpp b/common/ffs.cpp
index c5f3c41..ed414a8 100644
--- a/common/ffs.cpp
+++ b/common/ffs.cpp
@@ -46,7 +46,9 @@ VOID uint32ToUint24(UINT32 size, UINT8* ffsSize)
 
 UINT32 uint24ToUint32(const UINT8* ffsSize)
 {
-    return readUnaligned((UINT32*)ffsSize) & 0x00FFFFFF;
+    return (UINT32) ffsSize[0]
+        + ((UINT32) ffsSize[1] << 8U)
+        + ((UINT32) ffsSize[2] << 16U);
 }
 
 UString guidToUString(const EFI_GUID & guid, bool convertToString)
diff --git a/common/sha256.c b/common/sha256.c
index c99c162..9177f45 100644
--- a/common/sha256.c
+++ b/common/sha256.c
@@ -90,7 +90,7 @@ static const unsigned long K[64] = {
 #define MIN(x, y) (((x) < (y)) ? (x) : (y))
 #endif
 /* compress 512-bits */
-static int sha256_compress(struct sha256_state *md, unsigned char *buf)
+static void sha256_compress(struct sha256_state *md, unsigned char *buf)
 {
     uint32_t S[8], W[64], t0, t1;
     uint32_t t;
@@ -122,7 +122,6 @@ h  = t0 + t1;
     for (i = 0; i < 8; i++) {
         md->state[i] = md->state[i] + S[i];
     }
-    return 0;
 }
 /* Initialize the hash state */
 void sha256_init(struct sha256_state *md)
@@ -154,8 +153,7 @@ int sha256_process(struct sha256_state *md, const unsigned char *in,
         return -1;
     while (inlen > 0) {
         if (md->curlen == 0 && inlen >= block_size) {
-            if (sha256_compress(md, (unsigned char *) in) < 0)
-                return -1;
+            sha256_compress(md, (unsigned char *) in);
             md->length += block_size * 8;
             in += block_size;
             inlen -= block_size;
@@ -166,8 +164,7 @@ int sha256_process(struct sha256_state *md, const unsigned char *in,
             in += n;
             inlen -= n;
             if (md->curlen == block_size) {
-                if (sha256_compress(md, md->buf) < 0)
-                    return -1;
+                sha256_compress(md, md->buf);
                 md->length += 8 * block_size;
                 md->curlen = 0;
             }
diff --git a/common/zlib/deflate.c b/common/zlib/deflate.c
index 1ec7614..909606d 100755
--- a/common/zlib/deflate.c
+++ b/common/zlib/deflate.c
@@ -190,8 +190,11 @@ local const config configuration_table[10] = {
  * prev[] will be initialized on the fly.
  */
 #define CLEAR_HASH(s) \
-    s->head[s->hash_size-1] = NIL; \
-    zmemzero((Bytef *)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head));
+    do { \
+        s->head[s->hash_size-1] = NIL; \
+        zmemzero((Bytef *)s->head, \
+                 (unsigned)(s->hash_size-1)*sizeof(*s->head)); \
+    } while (0)
 
 /* ===========================================================================
  * Slide the hash table when sliding the window down (could be avoided with 32