commit 6039a2cb49c8af4c68460d2faf365a7e1c686c7b
Author: Jiri Denemark <jdenemar@redhat.com>
Date:   Mon Jul 30 12:14:54 2012 +0200

    daemon: Fix crash in virTypedParameterArrayClear
    
    Daemon uses the following pattern when dispatching APIs with typed
    parameters:
    
        VIR_ALLOC_N(params, nparams);
        virDomain*(dom, params, &nparams, flags);
        virTypedParameterArrayClear(params, nparams);
    
    In case nparams was originally set to 0, virDomain* API would fill it
    with the number of typed parameters it can provide and we would use this
    number (rather than zero) to clear params. Because VIR_ALLOC* returns
    non-NULL pointer even if size is 0, the code would end up walking
    through random memory. If we were lucky enough and the memory contained
    7 (VIR_TYPED_PARAM_STRING) at the right place, we would try to free a
    random pointer and crash.
    
    Let's make sure params stays NULL when nparams is 0.

Index: libvirt-0.9.13/daemon/remote.c
===================================================================
--- libvirt-0.9.13.orig/daemon/remote.c
+++ libvirt-0.9.13/daemon/remote.c
@@ -964,7 +964,7 @@ remoteDispatchDomainGetSchedulerParamete
         virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("nparams too large"));
         goto cleanup;
     }
-    if (VIR_ALLOC_N(params, nparams) < 0)
+    if (nparams && VIR_ALLOC_N(params, nparams) < 0)
         goto no_memory;
 
     if (!(dom = get_nonnull_domain(priv->conn, args->dom)))
@@ -1073,7 +1073,7 @@ remoteDispatchDomainGetSchedulerParamete
         virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("nparams too large"));
         goto cleanup;
     }
-    if (VIR_ALLOC_N(params, nparams) < 0)
+    if (nparams && VIR_ALLOC_N(params, nparams) < 0)
         goto no_memory;
 
     if (!(dom = get_nonnull_domain(priv->conn, args->dom)))
@@ -1254,7 +1254,7 @@ remoteDispatchDomainBlockStatsFlags(virN
         virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("nparams too large"));
         goto cleanup;
     }
-    if (VIR_ALLOC_N(params, nparams) < 0) {
+    if (nparams && VIR_ALLOC_N(params, nparams) < 0) {
         virReportOOMError();
         goto cleanup;
     }
@@ -1728,7 +1728,7 @@ remoteDispatchDomainGetMemoryParameters(
         virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("nparams too large"));
         goto cleanup;
     }
-    if (VIR_ALLOC_N(params, nparams) < 0) {
+    if (nparams && VIR_ALLOC_N(params, nparams) < 0) {
         virReportOOMError();
         goto cleanup;
     }
@@ -1793,7 +1793,7 @@ remoteDispatchDomainGetNumaParameters(vi
         virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("nparams too large"));
         goto cleanup;
     }
-    if (VIR_ALLOC_N(params, nparams) < 0) {
+    if (nparams && VIR_ALLOC_N(params, nparams) < 0) {
         virReportOOMError();
         goto cleanup;
     }
@@ -1858,7 +1858,7 @@ remoteDispatchDomainGetBlkioParameters(v
         virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("nparams too large"));
         goto cleanup;
     }
-    if (VIR_ALLOC_N(params, nparams) < 0) {
+    if (nparams && VIR_ALLOC_N(params, nparams) < 0) {
         virReportOOMError();
         goto cleanup;
     }
@@ -2118,7 +2118,7 @@ remoteDispatchDomainGetBlockIoTune(virNe
         goto cleanup;
     }
 
-    if (VIR_ALLOC_N(params, nparams) < 0) {
+    if (nparams && VIR_ALLOC_N(params, nparams) < 0) {
         virReportOOMError();
         goto cleanup;
     }
@@ -3621,7 +3621,7 @@ remoteDispatchDomainGetInterfaceParamete
         virNetError(VIR_ERR_INTERNAL_ERROR, "%s", _("nparams too large"));
         goto cleanup;
     }
-    if (VIR_ALLOC_N(params, nparams) < 0) {
+    if (nparams && VIR_ALLOC_N(params, nparams) < 0) {
         virReportOOMError();
         goto cleanup;
     }