Realtime: Fix a bug that caused realtime destroy command to crash

Also has could affect with anything that goes through ast_destroy_realtime.
If a CLI user used the command 'realtime destroy <family>' with only a single
column/value pair, Asterisk would crash when trying to create a variable list
from a NULL value.

ASTERISK-24231 #close
Reported by: Niklas Larsson
Review: https://reviewboard.asterisk.org/r/3985/

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@422984 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/config.c b/main/config.c
index 4af50b168ef01b85bf6b351827bc97db727051cc..8fbbbd302b0aa355fd5c37a1c7210b80b6446ebb 100644 (file)
--- a/main/config.c
+++ b/main/config.c
@@ -2749,9 +2749,22 @@ struct ast_config *ast_config_load2(const char *filename, const char *who_asked,
        return result;
 }
 
-#define realtime_arguments_to_fields(ap) realtime_arguments_to_fields2(ap, 0)
+#define realtime_arguments_to_fields(ap, result) realtime_arguments_to_fields2(ap, 0, result)
 
-static struct ast_variable *realtime_arguments_to_fields2(va_list ap, int skip)
+/*!
+ * \internal
+ * \brief
+ *
+ * \param ap list of variable arguments
+ * \param skip Skip argument pairs for this number of variables
+ * \param result Address of a variables pointer to store the results
+ *               May be NULL if no arguments are parsed
+ *               Will be NULL on failure.
+ *
+ * \retval 0 on success or empty ap list
+ * \retval -1 on failure
+ */
+static int realtime_arguments_to_fields2(va_list ap, int skip, struct ast_variable **result)
 {
        struct ast_variable *first, *fields = NULL;
        const char *newparam;
@@ -2778,10 +2791,14 @@ static struct ast_variable *realtime_arguments_to_fields2(va_list ap, int skip)
         * using the skip parameter:
         *
         *     va_start(ap, last);
-        *     x = realtime_arguments_to_fields(ap);
+        *     if (realtime_arguments_to_fields(ap, &x)) {
+        *         // FAILURE CONDITIONS
+        *     }
         *     va_end(ap);
         *     va_start(ap, last);
-        *     y = realtime_arguments_to_fields2(ap, 1);
+        *     if (realtime_arguments_to_fields2(ap, 1, &y)) {
+        *         // FAILURE CONDITIONS
+        *     }
         *     va_end(ap);
         */
        while (skip--) {
@@ -2795,10 +2812,15 @@ static struct ast_variable *realtime_arguments_to_fields2(va_list ap, int skip)
 
        /* Load up the first vars. */
        newparam = va_arg(ap, const char *);
+       if (!newparam) {
+               *result = NULL;
+               return 0;
+       }
        newval = va_arg(ap, const char *);
 
        if (!(first = ast_variable_new(newparam, newval, ""))) {
-               return NULL;
+               *result = NULL;
+               return -1;
        }
 
        while ((newparam = va_arg(ap, const char *))) {
@@ -2808,7 +2830,8 @@ static struct ast_variable *realtime_arguments_to_fields2(va_list ap, int skip)
                if (!(field = ast_variable_new(newparam, newval, ""))) {
                        ast_variables_destroy(fields);
                        ast_variables_destroy(first);
-                       return NULL;
+                       *result = NULL;
+                       return -1;
                }
 
                field->next = fields;
@@ -2818,7 +2841,8 @@ static struct ast_variable *realtime_arguments_to_fields2(va_list ap, int skip)
        first->next = fields;
        fields = first;
 
-       return fields;
+       *result = fields;
+       return 0;
 }
 
 struct ast_variable *ast_load_realtime_all_fields(const char *family, const struct ast_variable *fields)
@@ -2849,7 +2873,7 @@ struct ast_variable *ast_load_realtime_all(const char *family, ...)
        va_list ap;
 
        va_start(ap, family);
-       fields = realtime_arguments_to_fields(ap);
+       realtime_arguments_to_fields(ap, &fields);
        va_end(ap);
 
        if (fields) {
@@ -2897,12 +2921,19 @@ struct ast_variable *ast_load_realtime_fields(const char *family, const struct a
 struct ast_variable *ast_load_realtime(const char *family, ...)
 {
        RAII_VAR(struct ast_variable *, fields, NULL, ast_variables_destroy);
+       int field_res = 0;
        va_list ap;
 
        va_start(ap, family);
-       fields = realtime_arguments_to_fields(ap);
+       if (realtime_arguments_to_fields(ap, &fields)) {
+               field_res = -1;
+       }
        va_end(ap);
 
+       if (field_res) {
+               return NULL;
+       }
+
        if (!fields) {
                return NULL;
        }
@@ -3006,7 +3037,7 @@ struct ast_config *ast_load_realtime_multientry(const char *family, ...)
        va_list ap;
 
        va_start(ap, family);
-       fields = realtime_arguments_to_fields(ap);
+       realtime_arguments_to_fields(ap, &fields);
        va_end(ap);
 
        if (!fields) {
@@ -3043,7 +3074,7 @@ int ast_update_realtime(const char *family, const char *keyfield, const char *lo
        va_list ap;
 
        va_start(ap, lookup);
-       fields = realtime_arguments_to_fields(ap);
+       realtime_arguments_to_fields(ap, &fields);
        va_end(ap);
 
        if (!fields) {
@@ -3083,11 +3114,11 @@ int ast_update2_realtime(const char *family, ...)
        /* XXX: If we wanted to pass no lookup fields (select all), we'd be
         * out of luck. realtime_arguments_to_fields expects at least one key
         * value pair. */
-       lookup_fields = realtime_arguments_to_fields(ap);
+       realtime_arguments_to_fields(ap, &lookup_fields);
        va_end(ap);
 
        va_start(ap, family);
-       update_fields = realtime_arguments_to_fields2(ap, 1);
+       realtime_arguments_to_fields2(ap, 1, &lookup_fields);
        va_end(ap);
 
        if (!lookup_fields || !update_fields) {
@@ -3124,7 +3155,7 @@ int ast_store_realtime(const char *family, ...)
        va_list ap;
 
        va_start(ap, family);
-       fields = realtime_arguments_to_fields(ap);
+       realtime_arguments_to_fields(ap, &fields);
        va_end(ap);
 
        if (!fields) {
@@ -3157,13 +3188,16 @@ int ast_destroy_realtime_fields(const char *family, const char *keyfield, const
 int ast_destroy_realtime(const char *family, const char *keyfield, const char *lookup, ...)
 {
        RAII_VAR(struct ast_variable *, fields, NULL, ast_variables_destroy);
+       int res = 0;
        va_list ap;
 
        va_start(ap, lookup);
-       fields = realtime_arguments_to_fields(ap);
+       if (realtime_arguments_to_fields(ap, &fields)) {
+               res = -1;
+       }
        va_end(ap);
 
-       if (!fields) {
+       if (res) {
                return -1;
        }