[Qemu-devel] [for-2.11 PATCH 03/26] spapr_iommu: use g_strdup_printf() instead of snprintf()

[Greg Kurz]

Passing a stack allocated buffer of arbitrary length to snprintf()
without checking the return value can cause the resultant strings
to be silently truncated.

Signed-off-by: Greg Kurz <address@hidden>
---
 hw/ppc/spapr_iommu.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
index e614621a8317..740d42608b61 100644
--- a/hw/ppc/spapr_iommu.c
+++ b/hw/ppc/spapr_iommu.c
@@ -252,17 +252,19 @@ static int spapr_tce_table_realize(DeviceState *dev)
 {
     sPAPRTCETable *tcet = SPAPR_TCE_TABLE(dev);
     Object *tcetobj = OBJECT(tcet);
-    char tmp[32];
+    gchar *tmp;
 
     tcet->fd = -1;
     tcet->need_vfio = false;
-    snprintf(tmp, sizeof(tmp), "tce-root-%x", tcet->liobn);
+    tmp = g_strdup_printf("tce-root-%x", tcet->liobn);
     memory_region_init(&tcet->root, tcetobj, tmp, UINT64_MAX);
+    g_free(tmp);
 
-    snprintf(tmp, sizeof(tmp), "tce-iommu-%x", tcet->liobn);
+    tmp = g_strdup_printf("tce-iommu-%x", tcet->liobn);
     memory_region_init_iommu(&tcet->iommu, sizeof(tcet->iommu),
                              TYPE_SPAPR_IOMMU_MEMORY_REGION,
                              tcetobj, tmp, 0);
+    g_free(tmp);
 
     QLIST_INSERT_HEAD(&spapr_tce_tables, tcet, list);
 
@@ -307,7 +309,7 @@ void spapr_tce_set_need_vfio(sPAPRTCETable *tcet, bool 
need_vfio)
 sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, uint32_t liobn)
 {
     sPAPRTCETable *tcet;
-    char tmp[32];
+    gchar *tmp;
 
     if (spapr_tce_find_by_liobn(liobn)) {
         error_report("Attempted to create TCE table with duplicate"
@@ -318,8 +320,9 @@ sPAPRTCETable *spapr_tce_new_table(DeviceState *owner, 
uint32_t liobn)
     tcet = SPAPR_TCE_TABLE(object_new(TYPE_SPAPR_TCE_TABLE));
     tcet->liobn = liobn;
 
-    snprintf(tmp, sizeof(tmp), "tce-table-%x", liobn);
+    tmp = g_strdup_printf("tce-table-%x", liobn);
     object_property_add_child(OBJECT(owner), tmp, OBJECT(tcet), NULL);
+    g_free(tmp);
 
     object_property_set_bool(OBJECT(tcet), true, "realized", NULL);