Re: [Qemu-devel] [PATCH V2] net/colo-compare.c: Fix memory leak and code style issue.

[Jason Wang]

On 2019/7/4 下午4:36, Zhang Chen wrote:
From: Zhang Chen <chen.zh...@intel.com>

This patch to fix the origin "char *data" menory leak, code style issue
and add necessary check here.
Reported-by: Coverity (CID 1402785)

Signed-off-by: Zhang Chen <chen.zh...@intel.com>
---
  net/colo-compare.c | 28 +++++++++++++++++++++-------
  1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/net/colo-compare.c b/net/colo-compare.c
index 909dd6c6eb..ed349f5f6a 100644
--- a/net/colo-compare.c
+++ b/net/colo-compare.c
@@ -127,6 +127,17 @@ static int compare_chr_send(CompareState *s,
                              uint32_t vnet_hdr_len,
                              bool notify_remote_frame);
  
+static bool packet_matches_str(const char *str,
+                               uint8_t *buf,
+                               uint32_t packet_len)
+{
+    if (packet_len <= strlen(str)) {
+        return false;
+    }
+
+    return !memcmp(str, buf, strlen(str) + 1);


This assumes buf is NULL terminated (you pass notify_rs->buf) which is 
not correct I think?

Thanks


+}
+
  static void notify_remote_frame(CompareState *s)
  {
      char msg[] = "DO_CHECKPOINT";
@@ -1008,21 +1019,24 @@ static void compare_notify_rs_finalize(SocketReadState 
*notify_rs)
  {
      CompareState *s = container_of(notify_rs, CompareState, notify_rs);
  
-    /* Get Xen colo-frame's notify and handle the message */
-    char *data = g_memdup(notify_rs->buf, notify_rs->packet_len);
-    char msg[] = "COLO_COMPARE_GET_XEN_INIT";
+    const char msg[] = "COLO_COMPARE_GET_XEN_INIT";
      int ret;
  
-    if (!strcmp(data, "COLO_USERSPACE_PROXY_INIT")) {
+    if (packet_matches_str("COLO_USERSPACE_PROXY_INIT",
+                           notify_rs->buf,
+                           notify_rs->packet_len)) {
          ret = compare_chr_send(s, (uint8_t *)msg, strlen(msg), 0, true);
          if (ret < 0) {
              error_report("Notify Xen COLO-frame INIT failed");
          }
-    }
-
-    if (!strcmp(data, "COLO_CHECKPOINT")) {
+    } else if (packet_matches_str("COLO_CHECKPOINT",
+                                  notify_rs->buf,
+                                  notify_rs->packet_len)) {
          /* colo-compare do checkpoint, flush pri packet and remove sec packet 
*/
          g_queue_foreach(&s->conn_list, colo_flush_packets, s);
+    } else {
+        error_report("COLO compare got unsupported instruction '%s'",
+                     (char *)notify_rs->buf);
      }
  }