Fix 0 size malloc, part 2

lib/nghttp2_frame.c

@@ -515,11 +515,18 @@ int nghttp2_frame_unpack_settings_payload(nghttp2_settings *frame,
 {
   size_t payloadlen = niv * sizeof(nghttp2_settings_entry);
 
+  if(niv == 0) {
+    frame->iv = NULL;
+  } else {
     frame->iv = malloc(payloadlen);
+
     if(frame->iv == NULL) {
       return NGHTTP2_ERR_NOMEM;
     }
+
     memcpy(frame->iv, iv, payloadlen);
+  }
+
   frame->niv = niv;
   return 0;
 }
@@ -537,15 +544,27 @@ int nghttp2_frame_unpack_settings_payload2(nghttp2_settings_entry **iv_ptr,
                                            size_t payloadlen)
 {
   size_t i;
+
   *niv_ptr = payloadlen / NGHTTP2_FRAME_SETTINGS_ENTRY_LENGTH;
+
+  if(*niv_ptr == 0) {
+    *iv_ptr = NULL;
+
+    return 0;
+  }
+
+
   *iv_ptr = malloc((*niv_ptr)*sizeof(nghttp2_settings_entry));
+
   if(*iv_ptr == NULL) {
     return NGHTTP2_ERR_NOMEM;
   }
+
   for(i = 0; i < *niv_ptr; ++i) {
     size_t off = i * NGHTTP2_FRAME_SETTINGS_ENTRY_LENGTH;
     nghttp2_frame_unpack_settings_entry(&(*iv_ptr)[i], &payload[off]);
   }
+
   return 0;
 }
 
@@ -829,11 +848,19 @@ nghttp2_settings_entry* nghttp2_frame_iv_copy(const nghttp2_settings_entry *iv,
 {
   nghttp2_settings_entry *iv_copy;
   size_t len = niv*sizeof(nghttp2_settings_entry);
+
+  if(len == 0) {
+    return NULL;
+  }
+
   iv_copy = malloc(len);
+
   if(iv_copy == NULL) {
     return NULL;
   }
+
   memcpy(iv_copy, iv, len);
+
   return iv_copy;
 }
 

lib/nghttp2_helper.c

@@ -74,7 +74,13 @@ int nghttp2_reserve_buffer(uint8_t **buf_ptr, size_t *buflen_ptr,
 
 void* nghttp2_memdup(const void* src, size_t n)
 {
-  void* dest = malloc(n);
+  void* dest;
+
+  if(n == 0) {
+    return NULL;
+  }
+
+  dest = malloc(n);
   if(dest == NULL) {
     return NULL;
   }

lib/nghttp2_session.c

@@ -4814,6 +4814,7 @@ ssize_t nghttp2_session_mem_recv(nghttp2_session *session,
 
         varlen = iframe->frame.hd.length - 8;
 
+        if(varlen > 0) {
           iframe->raw_lbuf = malloc(varlen);
 
           if(iframe->raw_lbuf == NULL) {
@@ -4821,6 +4822,7 @@ ssize_t nghttp2_session_mem_recv(nghttp2_session *session,
           }
 
           nghttp2_buf_wrap_init(&iframe->lbuf, iframe->raw_lbuf, varlen);
+        }
 
         busy = 1;
 
@@ -5528,11 +5530,16 @@ int nghttp2_session_add_settings(nghttp2_session *session, uint8_t flags,
   if(frame == NULL) {
     return NGHTTP2_ERR_NOMEM;
   }
+
+  if(niv > 0) {
     iv_copy = nghttp2_frame_iv_copy(iv, niv);
     if(iv_copy == NULL) {
       free(frame);
       return NGHTTP2_ERR_NOMEM;
     }
+  } else {
+    iv_copy = NULL;
+  }
 
   if((flags & NGHTTP2_FLAG_ACK) == 0) {
     if(niv > 0) {