[Qemu-devel] [PATCH] qdict: fix unbounded stack for qdict_array_entries

[Peter Xu <peterx@redhat.com>]

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 qobject/qdict.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/qobject/qdict.c b/qobject/qdict.c
index 9833bd0..9188a87 100644
--- a/qobject/qdict.c
+++ b/qobject/qdict.c
@@ -704,19 +704,16 @@ int qdict_array_entries(QDict *src, const char *subqdict)
     for (i = 0; i < INT_MAX; i++) {
         QObject *subqobj;
         int subqdict_entries;
-        size_t slen = 32 + subqdict_len;
-        char indexstr[slen], prefix[slen];
-        size_t snprintf_ret;
+        char *prefix = g_strdup_printf("%s%u.", subqdict, i);
 
-        snprintf_ret = snprintf(indexstr, slen, "%s%u", subqdict, i);
-        assert(snprintf_ret < slen);
+        subqdict_entries = qdict_count_prefixed_entries(src, prefix);
 
-        subqobj = qdict_get(src, indexstr);
+        /* Remove ending "." */
+        prefix[strlen(prefix) - 1] = 0x00;
+        subqobj = qdict_get(src, prefix);
 
-        snprintf_ret = snprintf(prefix, slen, "%s%u.", subqdict, i);
-        assert(snprintf_ret < slen);
+        g_free(prefix);
 
-        subqdict_entries = qdict_count_prefixed_entries(src, prefix);
         if (subqdict_entries < 0) {
             return subqdict_entries;
         }
-- 
2.4.3