res_config_sqlite3: Fix crashes when reading peers from sqlite3 tables

Introduced realloaction of ast_str buf in sqlite3_escape functions in case
the returned buffer from threadstorage was actually too small.

Change-Id: I3c5eb43aaade93ee457943daddc651781954c445

diff --git a/res/res_config_sqlite3.c b/res/res_config_sqlite3.c
index 04b8e374c620d4fe5309bda5d1bc270751d89088..4c4b820516dd99bc982918193baf8a01febf83cd 100644 (file)
--- a/res/res_config_sqlite3.c
+++ b/res/res_config_sqlite3.c
@@ -127,8 +127,14 @@ static inline const char *sqlite3_escape_string_helper(struct ast_threadstorage
         * add two quotes, and convert NULL pointers to the word "NULL", but we
         * don't allow those anyway. Just going to use %q for now. */
        struct ast_str *buf = ast_str_thread_get(ts, maxlen);
-       char *tmp = ast_str_buffer(buf);
        char q = ts == &escape_value_buf ? '\'' : '"';
+       char *tmp;
+
+       if (ast_str_size(buf) < maxlen) {
+               /* realloc if buf is too small */
+               ast_str_make_space(&buf, maxlen);
+       }
+       tmp = ast_str_buffer(buf);
 
        ast_str_reset(buf);
        *tmp++ = q; /* Initial quote */
@@ -160,9 +166,15 @@ static const char *sqlite3_escape_column_op(const char *param)
 {
        size_t maxlen = strlen(param) * 2 + sizeof("\"\" =");
        struct ast_str *buf = ast_str_thread_get(&escape_column_buf, maxlen);
-       char *tmp = ast_str_buffer(buf);
+       char *tmp;
        int space = 0;
 
+       if (ast_str_size(buf) < maxlen) {
+               /* realloc if buf is too small */
+               ast_str_make_space(&buf, maxlen);
+       }
+       tmp = ast_str_buffer(buf);
+
        ast_str_reset(buf);
        *tmp++ = '"';
        while ((*tmp++ = *param++)) {