[libvirt] [PATCH] virsh: fix memory leak in cmdVolPath code

[ajia at redhat.com]

* tools/virsh.c: avoid memory leak in cmdVolPath.

* how to reproduce?

  % dd if=/dev/zero of=/var/lib/libvirt/images/foo.img count=1 bs=10M
  % virsh pool-refresh default
  % valgrind -v --leak-check=full virsh vol-path --vol
     /var/lib/libvirt/images/foo.img

* actual results:

Detected in valgrind run:

==16436== 32 bytes in 1 blocks are definitely lost in loss record 7 of 22
==16436==    at 0x4A05FDE: malloc (vg_replace_malloc.c:236)
==16436==    by 0x386A314B3D: xdr_string (in /lib64/libc-2.12.so)
==16436==    by 0x3DF8CD770D: xdr_remote_nonnull_string (remote_protocol.c:30)
==16436==    by 0x3DF8CD7EC8: xdr_remote_storage_vol_get_path_ret
(remote_protocol.c:2952)
==16436==    by 0x3DF8CDF161: virNetMessageDecodePayload (virnetmessage.c:286)
==16436==    by 0x3DF8CDE9E5: virNetClientProgramCall
(virnetclientprogram.c:318)
==16436==    by 0x3DF8CC28A2: call (remote_driver.c:3929)
==16436==    by 0x3DF8CC8412: remoteStorageVolGetPath
(remote_client_bodies.h:5219)
==16436==    by 0x3DF8C9BF14: virStorageVolGetPath (libvirt.c:11389)
==16436==    by 0x418ECA: cmdVolPath (virsh.c:8754)
==16436==    by 0x410CC2: vshCommandRun (virsh.c:12758)
==16436==    by 0x41F286: main (virsh.c:14110)
==16436==
==16436== LEAK SUMMARY:
==16436==    definitely lost: 32 bytes in 1 blocks


Signed-off-by: Alex Jia <ajia at redhat.com>
---
 tools/virsh.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/tools/virsh.c b/tools/virsh.c
index 841df61..d194a8b 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -9326,6 +9326,7 @@ cmdVolPath(vshControl *ctl, const vshCmd *cmd)
 {
     virStorageVolPtr vol;
     const char *name = NULL;
+    char * StorageVolPath;
 
     if (!vshConnectionUsability(ctl, ctl->conn))
         return false;
@@ -9334,7 +9335,13 @@ cmdVolPath(vshControl *ctl, const vshCmd *cmd)
         return false;
     }
 
-    vshPrint(ctl, "%s\n", virStorageVolGetPath(vol));
+    if ((StorageVolPath = virStorageVolGetPath(vol)) == NULL) {
+        virStorageVolFree(vol);
+        return false;
+    }
+
+    vshPrint(ctl, "%s\n", StorageVolPath);
+    VIR_FREE(StorageVolPath);
     virStorageVolFree(vol);
     return true;
 }
-- 
1.7.1