Re: [PATCH v2] qga: fix a memory leak in qmp_guest_exec_status()

[Marc-André Lureau]

On Wed, Jun 30, 2021 at 1:55 PM Yi Wang <wang.yi59@zte.com.cn> wrote:

From: Wang Yechao <wang.yechao255@zte.com.cn>

In some case, $GuestExecInfo.out.length maybe zero and the memory
is leaked in qmp_guest_exec_status(). Call g_free() on the fileds
directly to fix memory leak (NULL is ignored).

$GuestExecInfo.err.data has the same problem.

Signed-off-by: Yechao Wang <wang.yechao255@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

---
Changes in v2:
 - do not check the size > 0 when call g_free. Thanks to Marc.
---
 qga/commands.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/qga/commands.c b/qga/commands.c
index d3fec80..26e9358 100644
--- a/qga/commands.c
+++ b/qga/commands.c
@@ -214,17 +214,18 @@ GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **errp)
         if (gei->out.length > 0) {
             ges->has_out_data = true;
             ges->out_data = g_base64_encode(gei->out.data, gei->out.length);
-            g_free(gei->out.data);
             ges->has_out_truncated = gei->out.truncated;
         }
 
         if (gei->err.length > 0) {
             ges->has_err_data = true;
             ges->err_data = g_base64_encode(gei->err.data, gei->err.length);
-            g_free(gei->err.data);
             ges->has_err_truncated = gei->err.truncated;
         }
 
+        g_free(gei->out.data);
+        g_free(gei->err.data);
+
         QTAILQ_REMOVE(&guest_exec_state.processes, gei, next);
         g_free(gei);
     }
-- 
1.8.3.1

--

Marc-André Lureau