[xen staging] tools/xenstore: fix use after free bug in xenstore_control

[patchbot@xxxxxxx]

commit 1d24e551b99a85f50c69e72b7828a7d6c4c4e7a5
Author:     Juergen Gross <jgross@xxxxxxxx>
AuthorDate: Mon Jan 25 08:23:31 2021 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Mon Jan 25 15:13:29 2021 +0000

    tools/xenstore: fix use after free bug in xenstore_control
    
    There is a very unlikely use after free bug and a memory leak in
    live_update_start() of xenstore_control. Fix those.
    
    Coverity-Id: 1472399
    Fixes: 7f97193e6aa858 ("tools/xenstore: add live update command to 
xenstore-control")
    Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 tools/xenstore/xenstore_control.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/xenstore/xenstore_control.c 
b/tools/xenstore/xenstore_control.c
index 0c95cf767c..f6f4626c06 100644
--- a/tools/xenstore/xenstore_control.c
+++ b/tools/xenstore/xenstore_control.c
@@ -43,7 +43,12 @@ static int live_update_start(struct xs_handle *xsh, bool 
force, unsigned int to)
     if (len < 0)
         return 1;
 
+    ret = strdup("BUSY");
+    if (!ret)
+        return 1;
+
     for (time_start = time(NULL); time(NULL) - time_start < to;) {
+        free(ret);
         ret = xs_control_command(xsh, "live-update", buf, len);
         if (!ret)
             goto err;
--
generated by git-patchbot for /home/xen/git/xen.git#staging