Re: [Qemu-devel] [PATCH V4] net/colo-compare.c: Fix memory leak and code style issue.

[Zhang, Chen]

> -----Original Message-----
> From: Peter Maydell [mailto:address@hidden]
> Sent: Monday, July 22, 2019 9:19 PM
> To: Zhang, Chen <address@hidden>
> Cc: Li Zhijian <address@hidden>; Jason Wang <address@hidden>;
> qemu-dev <address@hidden>; Zhang Chen <address@hidden>
> Subject: Re: [PATCH V4] net/colo-compare.c: Fix memory leak and code style
> issue.
> 
> On Sun, 21 Jul 2019 at 10:04, Zhang Chen <address@hidden> wrote:
> >
> > From: Zhang Chen <address@hidden>
> >
> > This patch to fix the origin "char *data" memory leak, code style
> > issue and add necessary check here.
> > Reported-by: Coverity (CID 1402785)
> >
> > Signed-off-by: Zhang Chen <address@hidden>
> 
> > @@ -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);
> >      }
> 
> The notify_rs->buf is not NUL-terminated, so you can't use it in a %s format
> string like this. The simplest fix is just to not try to print the contents 
> of the
> incoming packet at all.
> 
> The rest of the patch looks good.

Thanks for reminding. I will remove it in next version.


Thanks
Zhang Chen

> 
> thanks
> -- PMM