[Pkg-xen-devel] Bug#784880: [PATCH for-4.6] tools: libxl: Handle failure to create qemu dm logfile

[Ian Campbell]

If libxl_create_logfile fails for some reason then
libxl__create_qemu_logfile previously just carried on and dereferenced
the uninitialised logfile.

Check for the error from libxl_create_logfile, which has already
logged for us.

This was reported as Debian bug #784880.

Reported-by: Russell Coker <russell at coker.com.au>
Signed-off-by: Ian Campbell <ian.campbell at citrix.com>
Cc: 784880 at bugs.debian.org
---
Should be backported.
---
 tools/libxl/libxl_dm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
index ad434f0..8ed2d2e 100644
--- a/tools/libxl/libxl_dm.c
+++ b/tools/libxl/libxl_dm.c
@@ -46,9 +46,11 @@ static const char *qemu_xen_path(libxl__gc *gc)
 static int libxl__create_qemu_logfile(libxl__gc *gc, char *name)
 {
     char *logfile;
-    int logfile_w;
+    int rc, logfile_w;
+
+    rc = libxl_create_logfile(CTX, name, &logfile);
+    if (rc) return rc;
 
-    libxl_create_logfile(CTX, name, &logfile);
     logfile_w = open(logfile, O_WRONLY|O_CREAT|O_APPEND, 0644);
     free(logfile);
 
-- 
2.1.4