[PULL,1/1] s390x/s390-virtio-ccw: fix off-by-one in loadparm getter

Commit Message

Cornelia Huck July 31, 2020, 8:55 a.m. UTC

From: Halil Pasic <[e-mail]>

As pointed out by Peter, g_memdup(ms->loadparm, sizeof(ms->loadparm) + 1)
reads one past of the end of ms->loadparm, so g_memdup() can not be used
here.

Let's use g_strndup instead!

Fixes: d6645483285f ("s390x/s390-virtio-ccw: fix loadparm property getter")
Fixes: Coverity CID 1431058
Reported-by: Peter Maydell <[e-mail]>
Signed-off-by: Halil Pasic <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Reviewed-by: Peter Maydell <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Cornelia Huck <[e-mail]>
---
 hw/s390x/s390-virtio-ccw.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

Patch

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 403d30e13bca..e72c61d2eae0 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -701,12 +701,9 @@  bool hpage_1m_allowed(void)
 static char *machine_get_loadparm(Object *obj, Error **errp)
 {
     S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
-    char *loadparm_str;
 
     /* make a NUL-terminated string */
-    loadparm_str = g_memdup(ms->loadparm, sizeof(ms->loadparm) + 1);
-    loadparm_str[sizeof(ms->loadparm)] = 0;
-    return loadparm_str;
+    return g_strndup((char *) ms->loadparm, sizeof(ms->loadparm));
 }
 
 static void machine_set_loadparm(Object *obj, const char *val, Error **errp)